Research ArticleComparative Study on Two Pretreatment Processes for ChemicalPhase Analysis of Gold in Geological Samples by AtomicAbsorption Spectrometry

Xiaodan Tang 12 Hang Li2 Hongyan Liu12 Bing Li2 Yuyan Zhao2 Jilong Lu2

Jian Zhou13 and Qingqing Liu 13

1Key Laboratory of Geochemical Exploration Ministry of Land and ResourcesInstitute of Geophysical and Geochemical Exploration Chinese Academy of Geological Sciences Langfang 065000 China2College of Geo-exploration Science and Technology Jilin University Changchun 130026 China3UNESCO International Centre on Global-Scale Geochemistry Langfang 065000 China

Correspondence should be addressed to Qingqing Liu liuqingqingiggecn

Received 24 February 2019 Revised 31 May 2019 Accepted 11 June 2019 Published 10 July 2019

Academic Editor Jaroon Jakmunee

Copyright copy 2019 Xiaodan Tang et alis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Sample pretreatment is important for chemical phase analysis of elements In this study the geological samples of theLaozuoshan gold mine are chosen to pretreat by ultrasonic centrifugation and cyclotron oscillation and the content of gold ineight chemical phases (water-soluble ion exchange and clay adsorption organic matter bound iron-manganese oxide boundnaked or seminaked carbonate bound sulfide bound and insoluble silicate states) is determined by atomic absorptionspectrometry e results show that the gold content of water-soluble ion exchange and clay adsorption iron-manganeseoxide and naked or seminaked states in the rock and ore samples is low and some samples have high gold content of insolublesilicate states in the two methods However the gold content of organic matter bound carbonate bound and sulfide boundstates obtained by ultrasonic centrifugation and cyclotron oscillation methods is significantly different According to the X-rayfluorescence spectrometry data and the actual geological condition the result given by the cyclotron oscillation method is morereasonable e gold content of sulfide bound state in sediment samples is the highest and consistent with the mineralinformation which could be applied to preliminarily predict the rock and ore conditions in the corresponding mining areas Incontrast with ultrasonic centrifugation the cyclotron oscillation method has the advantages of simplicity high efficiencypracticality and environmental protection and it can be better used for the determination of gold chemical phase state ingeological samples by atomic absorption spectrometry

1 Introduction

Gold is an extraordinary mineral resource with importantstatus and wide application in geology [1 2] electronics[3 4] chemical [5 6] and medical [7 8] fields However ithas low content and uneven distribution in the earthrsquoscrust which makes it difficult to analyze In recent yearsgold mineral resources are increasingly depleted undercontinuous development and utilization Searching forhidden gold mines and re-extraction of gold in tailings hasbecome a hot spot for exploration and research For the

rational effective and comprehensive development andutilization of gold mineral resources it is necessary toexplore the occurrence status of gold in various geologicalsamples

Chemical phase analysis [9] one of the important meansto ascertain the occurrence states of elements enables theseparation and determination of different phase elements byselective solvent dissolution or leaching of one or a class ofminerals e predecessors have done some research on thechemical phase analysis of gold e phase of gold in geo-chemical samples was initially divided into six namely

HindawiJournal of Analytical Methods in ChemistryVolume 2019 Article ID 1792792 8 pageshttpsdoiorg10115520191792792

natural gold carbonate phase pyrite wrapped phase oxidephase sulfide phase and quartz-silicate combination phase[10] In consideration of differences in landscape geo-chemical conditions and biogeochemical effects thechemical phase of gold was increased to eight by introducingclay absorbed phase (exchangeable phase) and organic phase[11] en the existence forms of ldquoinvisible goldrdquo in severalcomplex ores and the analytical methods for the de-termination of gold in different chemical phases weresummarized [12 13] e selective solvents required forchemical phase analysis of gold ore were explored in ex-periments [14] Furthermore gold chemical phase analysis isapplied to the geological analysis of different mines to ex-plore its indication significance for prospecting [15 16]

In order to accurately quickly and effectively determinethe content of phase gold in geological samples the con-tinuous improvement and innovation of analytical tech-niques are particularly important In the phase analysisprocess sample pretreatment [17ndash20] is one of the key stepswhich seriously affects the accuracy of the results and di-rectly determines the success of the experiment or not At thesame time the test methods will also have a certain impacton the experimental results Commonly used gold testmethods include titration [21] atomic absorption spec-trometry (AAS) [20 22ndash24] inductively coupled plasmaoptical emission spectroscopy [25 26] and inductivelycoupled plasma mass spectrometry [27 28] Among themthe AAS meets the test conditions of most geologicalsamples and its analytical techniques are relatively matureand widely used [29ndash32] erefore the AAS was used hereto determine the gold content

e main purpose of this study was to explore contrastand validate the pretreatment process applicable to the goldchemical phase analysis in geological samples by AASFirstly the geological samples of the Laozuoshan gold de-posit were chosen to analyze the gold-related elements byX-ray fluorescence spectrometry (XRF) [33 34] to pre-liminarily predict the content and occurrence state of golden the samples were pretreated by ultrasonic centrifu-gation and cyclotron oscillation methods for chemical phaseanalysis and the content of gold in eight phases (water-soluble ion exchange and clay adsorption organic matterbound iron-manganese oxide bound naked or seminakedcarbonate bound sulfide bound and insoluble silicate states)was determined by AAS which filled the gap in the chemicalphase analysis of the Laozuoshan gold mine Finally the twopretreatment processes were compared and evaluated bycombining the XRF data and geological and geochemicalcharacteristics of the Laozuoshan gold deposit [35 36]

2 Materials and Methods

21 Reagents and Standards Hydrochloric acid (HCl) nitricacid (HNO3) and hydrofluoric acid (HF) in guaranteedreagent grade and ultrapure deionized water with a re-sistivity of 182MΩmiddotcm at 25degC were used for samplepreparatione other reagents were of analytical gradeemain reagents prepared in the experiment were 50 gLammonium citrate solution 4 gL sodium hydroxide

(NaOH)-40 gL sodium pyrophosphate (Na4P2O7) mixedsolution 100 gL ammonium citrate-40 gL hydroxylaminehydrochloride mixed solution (pHasymp 7 with ammonia) 5 gLiodine (I2)-15 gL potassium iodide (KI) mixed solution(pHasymp 10 with ammonia) 4molL acetic acid (HAc) solu-tion 5mLL bromine (Br2)-100 gL sodium chloride (NaCl)mixed solution 250 gL ferric chloride (FeCl3) solution (with1 HCl) 10 gL thiourea solution (with 1 HCl) and aquaregia

National standard gold single element solution (GSB 04-1715-2004 1000 μgmL) in 15molL HCl was obtained fromNational Center of Analysis and Testing for NonferrousMetals and Electronic Materialse gold standard solutionsrequired in the experiment were prepared by stepwise di-lution Four certified reference materials (CRMs)(GBW07247a GBW07298a GBW07105 and GBW07309)were acquired from the Institute of Geophysical and Geo-chemical Exploration Chinese Academy of GeologicalSciences (Langfang China)

22 Instrumentation Samples were triturated by a plane-tary ball mill (QM-3SP4 Laibu China) weighed with anelectronic balance (ATY124 Shimadzu Japan) and ashedin a muffle furnace (SXL-1008 Jinghong China) eelectric heating plate (SB-18-4 Shanghai Shiyan China)was applied in total gold digestion process e cyclotronoscillator (HY-8A Jintan Jingda China) centrifuge (TDL-5A Anting China) ultrasonic cleaner (KQ-400KDEKunshan China) and vacuum pump (SHB-III Great WallChina) devices were used for phase gold pretreatment econstant-temperature water bath (HH-S26S Jintan In-struments China) was applied to the gold desorptionSome gold-related elements were determined by an X-rayfluorescence spectrometer (EDX 6000B Tianrui China)Gold determination was performed on an AAS (A3 PerseeChina) instrument e optimum operating parameters ofthe XRF flame and graphite furnace AAS are summarizedin Table 1 and the graphite furnace heating process isshown in Table 2

23 Sample Processing e collected ore and sedimentsamples of the Laozuoshan gold deposit were dried smashedby a crusher finely grinded to powder by a planetary ballmill filtered through a 200-mesh sieve and placed in adesiccator for use

24 Experimental Procedure of Total Gold With reference tothe geological and mineral industry standard DZT027919-2016 of the Peoplersquos Republic of China combined with theactual situation of the laboratory the leaching experiment oftotal gold in geological samples was designed as the fol-lowing two steps

(1) High-temperature ashing-acid digestion Ten gramsof sample were accurately weighed into a porcelaincrucible heated to 700degC in a muffle furnace andheld for 15 hours After cooling the sample wastransferred to a Teflon Erlenmeyer flask (TEF) into

2 Journal of Analytical Methods in Chemistry

which 50mL 50 aqua regia and 10mL HF wereadded e TEF was placed on a hot plate andheated to dissolve the sample and the solution waskept slightly boiled evaporated to half and thencooled

(2) Gold enrichment and desorption 80mL ultrapuredeionized water 3mL FeCl3 solution and a gold-absorbing foam (3times 2times1 cm3 sim035 g) were addedto the resulting solution of the TEF which was thenplaced on a cyclotron and shaken for 30minutes at afrequency of 200 rpm Subsequently the foam wastaken out from the flask the residual acid and residuewere rinsed with ultrapure deionized water thewater was drained with the filter paper and thesolution was placed in a 50mL colorimetric tube inwhich 25mL thiourea solution had been added After45minutes in the boiling water bath the foam wasrepeatedly pressed and taken out e resulting so-lution was cooled to room temperature and to bemeasured

At the same time the same method was used for theblank control experiment

25 Experimental Procedure of PhaseGold Methods I and IIrepresent ultrasonic centrifugation and cyclotron oscilla-tion processes respectively Method I uses ultrasonic waves

to propagate in the form of longitudinal waves within theliquid cause the liquid molecules to vibrate at theirequilibrium positions and then increase the solubility ofthe sample in the solvent When the ultrasonic power isstrong enough the cavitation even instantaneous hightemperature and high pressure will generate is extremeenvironment is easy to accelerate the internal motion ordepolymerization of molecules and cause chemical re-action Here the samples were sonicated at the frequency of40 kHz for 1 hour in an ultrasonic cleaner with the power of200W and the temperature of 25degCndash30degC and thencentrifuged at 4500 rpm for 15minutes in a centrifugeMethod II also called the circumferential oscillation is a360deg rotation oscillation on the horizontal surface Duringthe oscillation process the oscillated liquid will appear in aswirl shape in the container and its turbulence is moreintense which allows the sample to be distributed moreevenly throughout the extractant and thereby acceleratesthe diffusion rate of the extracted gold into the solutionHere the samples were shaken at the frequency of 200 rpmfor 15 hours on a cyclotron oscillator with the power of100W and the amplitude of 20mm

251 Water-Soluble State (WSS) Method I Ten grams ofsample and 50mL ultrapure deionized water were accu-rately taken into a centrifuge cup shaken well and soni-cated in an ultrasonic cleaner for 1 hour e temperatureof the ultrasonic cleaner should be maintained at 25degCndash30degC during the ultrasound process en the sample wascentrifuged at 4500 rpm for 15minutes and filtered througha 045 μm membrane e residue and filter flask wererinsed several times with ultrapure deionized water eresidue was retained in the original centrifuge cup for thegold extraction of the next phase e filtrate was com-pletely transferred to a TEF heated and concentrated toabout 20mL on a hot plate 25mL of aqua regia was addedto the resulting filtrate in the TEF shaken well and heatedto dissolve gold e resulting solution was evaporated toabout 20mL and cooled e subsequent operation was thesame as Gold enrichment and desorption described inSection 24

Method II Ten grams of sample and 50mL ultrapuredeionized water were accurately taken into a conical flaskwith cover shaken at 200 rpm for 15 hours on a cyclotronoscillator and filtered through a 045 μm membrane eresidue conical flask and filter flask were rinsed severaltimes with ultrapure deionized water e residue wasretained in the original conical flask for the gold extractionof the next phase e filtrate was completely transferred toa new TEF and the subsequent operation was the same asMethod I above

252 Ion Exchange and Clay Adsorption State (IECAS)Fifty millilitres of 50 gL ammonium citrate was added tothe remained residue after the gold extraction of WSS andthe subsequent operations were the same as methods I andII of Section 251 respectively

Table 1 Instrument operating parameters

Parameter SettingXRFInitialization element AgInitialization channel 2210Tube current 250 μATube voltage 40 kVCounting rate 1Vacuum time 25 sMeasure time 100 sReplicates 3Flame AASElement AuWavelength 2428 nmSpectral bandwidth 04 nmLamp current 20mAFilter coefficient 06Integration time 3 sBurner height 6mmFlame type Air-C2H2

Graphite furnace AASElement AuWavelength 2428 nmSpectral bandwidth 04 nmLamp current 40mAFilter coefficient 01Integration time 3 sInjection volume 20 μLMeasurement methods Peak areaXRF X-ray fluorescence spectrometry AAS atomic absorptionspectrometry

Journal of Analytical Methods in Chemistry 3

253 Organic Matter Bound State (OMBS) Fifty millilitresof 4 gL NaOH-40 gL Na4P2O7 mixed solution was added tothe remained residue after the gold extraction of IECAS andthe subsequent operations were the same as methods I and IIof Section 251 respectively

254 Iron-Manganese Oxide Bound State (IMOBS) Fiftymillilitres of 4 gL 100 gL ammonium citrate-40 gL hy-droxylamine hydrochloride mixed solution was added to theremained residue after the gold extraction of OMBS and thesubsequent operations were the same as methods I and II ofSection 251 respectively

255 Naked or Seminaked State (NSNS) Fifty millilitres of5 gL I2-15 gL KI mixed solution was added to the remainedresidue after the gold extraction of IMOBS and the sub-sequent operations were the same as methods I and II ofSection 251 respectively

256 Carbonate Bound State (CBS) Fifty millilitres of4molL HAc was added to the remained residue after thegold extraction of NSNS and the subsequent operationswere the same as methods I and II of Section 251respectively

257 Sulfide Bound State (SBS) Fifty millilitres of 5mLLBr2-100 gL NaCl mixed solution was added to the remainedresidue after the gold extraction of CBS and the subsequentoperations were the same as methods I and II of Section251 respectively

258 Insoluble Silicate State (ISS) Methods I and II 50mLof 50 aqua regia and 10mLHF were added to the remainedresidue after the gold extraction of SBS and the subsequentoperations were the same as the experimental procedure oftotal gold above respectively

26CalibrationCurves Under the optimal conditions of theinstrument in Table 1 two series of calibration curves wereestablished separately with five concentrations of goldstandard solutions and a blank Curve I ranging from 0to 10 μgmL for flame AAS was y 00017 + 00522x witha correlation coefficient of 09998 and curve II rangingfrom 0 to 50 ngmL for graphite furnace AAS wasy 00003 + 00022x with a correlation coefficient of 09996which indicated that a good linear regression was establishedbetween the absorbances and the concentrations

3 Results and Discussion

31 Validation of Analytical Methods e accuracy andprecision requirements of analytical methods can be vali-dated by separately calculating the logarithmic deviation(Δ logC) and relative standard deviation (RSD) between themeasured value and the standard of the CRMe content ofmain constant and trace elements in CRMs GBW07105 andGBW07309 by XRF is listed in Table S1 the total goldcontent of CRMs GBW7247a and GBW07298a by AAS isshown in Table S2 and the relevant quality control pa-rameters Δ logC and RSD could be evaluated from thefollowing equations

Δ lgC (GBW) lgCminus

i minus lgCs

11138681113868111386811138681113868

11138681113868111386811138681113868

RSD (GBW)

1113936ni1 Ci minusCs( 1113857

2(nminus 1)

1113969

Cs

times 100

(1)

where n 5 is the number of parallel experiments Cs is thenational standard value of the CRM and Ci and Ci denotethe single and mean measured value of the CRMrespectively

In Tables S1 and S2 the Δ logC values were in the rangeof 016ndash252 and the RSDs were all less than 680 edetection limits estimated as three times the standard de-viation of the blank were 0002 μgmL and 0012 ngmL forflame and graphite furnace AAS respectively According tothe requirements of the geological and mineral industrystandard DZT0011-2015 of the Peoplersquos Republic of Chinathe detection limits of flame and graphite furnace AAS werelower than those required by the standard and the ΔlogCand RSD values of four CRMs were much smaller than thestandard monitoring limits ese demonstrated that theaccuracy and precision of the experimental method werehigh and satisfied the detection requirements

32 Constant and Trace Element Content Combined withthe geological characteristics of the Laozuoshan gold de-posit the main constant elements Al Ca Fe K Mg Na andSi (expressed by oxide) and trace elements Co Cu Mn NiPb Sn and Zn of the sample were determined by XRF andthe results are shown in Tables S3 and 3 In the Laozuoshangold mine the main ore minerals were arsenopyrite pyr-rhotite pyrite and chalcopyrite and the major gangueminerals were mainly quartz diopside and calcite themeasurement results were clearly related to these geologicaldata Among them the rock ore sample LZY01 containedsulfide quartz vein and its Fe Cu Pb and Co contents wereobviously high LZY02 was granulite its main mineral was

Table 2 Heating program for graphite furnace

Step Temperature (degC) Heating time (s) Holding time (s) Internal gas flow (mLmin)Dry 110 10 10 200Ashing 600 10 15 200Atomization 1800 0 3 0Exclusion 1900 1 2 200

4 Journal of Analytical Methods in Chemistry

quartz and feldspar and its Si content was high LZY03 hadremarkable characteristics of brass mineralization its Cucontent was the highest among the six samples and thecontent of other metal elements was also high LZY04 withno obvious high content elements was a rock sample in thelater stage of mineralization LZY05 was an altered rocksample with a certain degree of quartzification duringmineralization and its Si content was high e sedimentsample LZS01 was collected from the upstream river sandnear the original gold mining field its Si content was highand its Fe Cu Co and Mn contents were low Based on theabove element content information it was preliminarilypredicted that the gold in the sample mainly existed in theSBS the gold content of LZY01 and LZY03 would be higherthan that of others and the gold content in the sedimentmight be lower than that in the rock ore

33 Total Gold Content e measurement results of thetotal gold in the sample by AAS are shown in Tables S4and 4 e total gold content from high to low wasLZY01 gt LZY03gt LZY02gt LZY04gt LZY05gt LZS01 whichmet the expectation of gold-related elements above andfurther indicated that gold was enriched in sulfide quartzveins e gold in the sediment was derived from the debrisformed by the weathering and erosion of the primary rockbut the tiny gold particles were carried away by water flowso the gold content of the sediment was lower than that ofthe rock ore

34 Comparison of Phase Analysis Results e gold contentof each chemical phase in the sample was determined byAAS the weighted value (the sum of eight phase goldcontents) the percentage (the ratio of the phase goldcontent to the weighted value) and the leaching rate (theratio of the weighted value to the total content) werecalculated and all the results are listed in Tables S5 S6 and5 For more intuitive analysis and discussion of relevantdata a histogram for the percentage of gold in eachchemical phase was plotted in Figure 1 Comparing the

extraction effect of methods I and II for gold in eachchemical phase two common points were found (1) epercentages of WSS IECAS IMOBS and NSNS were lowand their maximum value did not exceed 2 which in-dicated that these phase states contained less gold (2) egold percentage of ISS in LZY01 and LZY03 was close to50 due to the inclusion of sulfide quartz veins Except forabove common points there were significant differencesbetween the two methods in Figure 1 For all the samplesthe gold content of OMBS obtained by ultrasonic centri-fugation was much higher than that by cyclotron oscilla-tion and the gold content of SBS extracted by cyclotronoscillation was much more than that by ultrasonic cen-trifugation e average percentage of gold in OMBSextracted by ultrasonic centrifugation was up to 6724and the average percentage of gold in SBS extracted bycyclotron oscillation was up to 6237 Moreover the goldcontent of CBS extracted by cyclotron oscillation was alsolarger than that by ultrasonic centrifugation Since thegold-bearing minerals in the Laozuoshan gold mining areawere mainly arsenopyrite pyrrhotite pyrite and chalco-pyrite and the content of sulfide in samples was high thusthe gold extraction result of each chemical phase by cy-clotron oscillation method was more in line with actualgeological conditions When extracting gold in OMBSultrasound would accelerate the internal motion and de-polymerization of molecules which might lead to the earlyrelease of the subsequent gold in CBS and SBS

In addition the gold content of SBS in sedimentsamples was the highest indicating that the sedimentsystem was affected by the primary halo and its main phasecomposition was consistent with the mineral informationin the mining area us the gold content and phase be-havior of sediments could be used to preliminarily predictthe rock and ore conditions in the corresponding mining

Table 3 e content of main constant and trace elements

Constant element (unit 10minus2)Sample Al2O3 CaO Fe2O3 K2O MgO Na2O SiO2

LZY01 3140 7598 34367 0188 0586 2213 44198LZY02 8916 14113 9429 1693 2472 0201 58545LZY03 7945 20719 8677 0166 1746 0668 47335LZY04 8062 15368 10244 2061 2182 0292 56328LZY05 12504 9485 3513 1600 1136 1968 61755LZS01 11318 1524 1620 3443 0431 2457 63061

Trace element (unit 10minus6)Sample Co Cu Mn Ni Pb Sn ZnLZY01 255089 900836 1055870 48409 39484 0607 133309LZY02 19689 120047 2003167 30235 7462 0826 160777LZY03 18392 1856429 1848804 11438 14410 0742 134596LZY04 20457 243509 1973857 20027 4505 0784 143916LZY05 6162 157230 554794 4761 13303 1757 24905LZS01 1475 26164 117641 2562 48004 0052 297242

Table 4 Analysis results of total gold

Sample LZY01 LZY02 LZY03 LZY04 LZY05 LZS01Content (10minus6) 46985 3980 26060 1840 1490 0176

Journal of Analytical Methods in Chemistry 5

areas analyze and deduce the hard-to-obtain medium withthe easily obtained sampling medium estimate the deepmineral information with the aid of shallow source in-formation and then provide some theoretical guidance forthe exploration of concealed gold deposits and the de-lineation of gold anomalies

Comparing the gold leaching rates of the two methods inTable 5 the average leaching rate of ultrasonic centrifugationand cyclotron oscillation was 10563 and 9659 re-spectively e cyclotron oscillation method had a betterleaching effect on gold since its leaching rate was closer to100 e power and vibration frequency of method I weremuch higher than those of method II but its extractionefficiency was not as good asmethod II At the same time thehigh power and high frequency vibration of method I alsoled to the enhanced cavitation and the solution was easy torise to high temperature so the temperature needed to bestrictly monitored and adjusted during the experimentprocess which increased the complexity of the experimentintroduced more errors and made the measurement resultsdeviate from the geological conditions While the experi-mental procedure of method II was simple and easy theerror was relatively reduced so the cyclotron oscillationmethod had higher leaching ability and efficiency for goldand its phase analysis result was more in line with the XRFdata and the actual geological information Furthermoreultrasound would cause a certain degree of noise pollution

100

80

60

40

20

0

Percentage

I II I II I II I II I II I IILZY01 LZY02 LZY03 LZY04 LZY05 LZS01

ISSIMOBSSBSOMBS

CBSIECASNSNSWSS

Figure 1 e histogram for the percentage of gold in each chemicalphase (I ultrasonic centrifugation II cyclotron oscillation WSSwater-soluble state IECAS ion exchange and clay adsorption stateOMBS organic matter bound state IMOBS iron-manganese oxidebound state NSNS naked or seminaked state CBS carbonate boundstate SBS sulfide bound state ISS insoluble silicate state)

Table 5 Analysis results of phase gold

Sample Method WSS IECAS OMBS IMOBS NSNS CBS SBS ISS Weighted value Leaching rate

LZY01

I 0211 0222 21856 0024 0213 0215 0272 21585 44598 9492(047) (050) (4901) (005) (048) (048) (061) (4840)

II 0224 0238 0240 0026 0216 0384 22261 21572 45161 9612(050) (053) (053) (006) (048) (085) (4929) (4777)

LZY02

I 0000 0019 4456 0002 0011 0005 0036 0065 4594 11543(000) (041) (9700) (004) (024) (011) (078) (141)

II 0006 0006 0051 0007 0003 0032 3079 0605 3789 9520(016) (016) (135) (018) (008) (084) (8126) (1597)

LZY03

I 0118 0112 12906 0015 0133 0031 0158 11439 24912 9560(047) (045) (5181) (006) (053) (012) (063) (4592)

II 0125 0194 1163 0014 0115 0792 11153 11817 25373 9736(049) (076) (458) (006) (045) (312) (4396) (4657)

LZY04

I 0000 0012 2105 0001 0000 0003 0110 0109 2340 12717(000) (051) (8996) (004) (000) (013) (470) (466)

II 0000 0019 0203 0003 0000 0041 1113 0180 1559 8473(000) (122) (1302) (019) (000) (263) (7139) (1155)

LZY05

I 0000 0019 1566 0002 0000 0003 0016 0004 1610 10805(000) (118) (9727) (012) (000) (019) (099) (025)

II 0000 0006 0213 0001 0000 0042 1129 0046 1437 9644(000) (042) (1482) (007) (000) (292) (7857) (320)

LZS01

I 0000 0000 0030 0010 0035 0006 0072 0010 0163 9261(000) (000) (1840) (613) (2147) (368) (4417) (613)

II 0000 0006 0022 0002 0000 0023 0096 0044 0193 10966(000) (311) (1140) (104) (000) (1192) (4974) (2280)

I ultrasonic centrifugation II cyclotron oscillation WSS water-soluble state IECAS ion exchange and clay adsorption state OMBS organic matterbound state IMOBS iron-manganese oxide bound state NSNS naked or seminaked state CBS carbonate bound state SBS sulfide bound state ISSinsoluble silicate state Among the eight phase states the value outside the parentheses is the content of gold in each phase and the unit is 10minus6 the valuein parentheses is the ratio of the phase gold content to the weighted value and the unit is e weighted value is the sum of the eight phase gold contentsand the unit is 10minus6 the leaching rate is the ratio of the weighted value to the total content and the unit is

6 Journal of Analytical Methods in Chemistry

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

which 50mL 50 aqua regia and 10mL HF wereadded e TEF was placed on a hot plate andheated to dissolve the sample and the solution waskept slightly boiled evaporated to half and thencooled

(2) Gold enrichment and desorption 80mL ultrapuredeionized water 3mL FeCl3 solution and a gold-absorbing foam (3times 2times1 cm3 sim035 g) were addedto the resulting solution of the TEF which was thenplaced on a cyclotron and shaken for 30minutes at afrequency of 200 rpm Subsequently the foam wastaken out from the flask the residual acid and residuewere rinsed with ultrapure deionized water thewater was drained with the filter paper and thesolution was placed in a 50mL colorimetric tube inwhich 25mL thiourea solution had been added After45minutes in the boiling water bath the foam wasrepeatedly pressed and taken out e resulting so-lution was cooled to room temperature and to bemeasured

At the same time the same method was used for theblank control experiment

25 Experimental Procedure of PhaseGold Methods I and IIrepresent ultrasonic centrifugation and cyclotron oscilla-tion processes respectively Method I uses ultrasonic waves

to propagate in the form of longitudinal waves within theliquid cause the liquid molecules to vibrate at theirequilibrium positions and then increase the solubility ofthe sample in the solvent When the ultrasonic power isstrong enough the cavitation even instantaneous hightemperature and high pressure will generate is extremeenvironment is easy to accelerate the internal motion ordepolymerization of molecules and cause chemical re-action Here the samples were sonicated at the frequency of40 kHz for 1 hour in an ultrasonic cleaner with the power of200W and the temperature of 25degCndash30degC and thencentrifuged at 4500 rpm for 15minutes in a centrifugeMethod II also called the circumferential oscillation is a360deg rotation oscillation on the horizontal surface Duringthe oscillation process the oscillated liquid will appear in aswirl shape in the container and its turbulence is moreintense which allows the sample to be distributed moreevenly throughout the extractant and thereby acceleratesthe diffusion rate of the extracted gold into the solutionHere the samples were shaken at the frequency of 200 rpmfor 15 hours on a cyclotron oscillator with the power of100W and the amplitude of 20mm

251 Water-Soluble State (WSS) Method I Ten grams ofsample and 50mL ultrapure deionized water were accu-rately taken into a centrifuge cup shaken well and soni-cated in an ultrasonic cleaner for 1 hour e temperatureof the ultrasonic cleaner should be maintained at 25degCndash30degC during the ultrasound process en the sample wascentrifuged at 4500 rpm for 15minutes and filtered througha 045 μm membrane e residue and filter flask wererinsed several times with ultrapure deionized water eresidue was retained in the original centrifuge cup for thegold extraction of the next phase e filtrate was com-pletely transferred to a TEF heated and concentrated toabout 20mL on a hot plate 25mL of aqua regia was addedto the resulting filtrate in the TEF shaken well and heatedto dissolve gold e resulting solution was evaporated toabout 20mL and cooled e subsequent operation was thesame as Gold enrichment and desorption described inSection 24

Method II Ten grams of sample and 50mL ultrapuredeionized water were accurately taken into a conical flaskwith cover shaken at 200 rpm for 15 hours on a cyclotronoscillator and filtered through a 045 μm membrane eresidue conical flask and filter flask were rinsed severaltimes with ultrapure deionized water e residue wasretained in the original conical flask for the gold extractionof the next phase e filtrate was completely transferred toa new TEF and the subsequent operation was the same asMethod I above

252 Ion Exchange and Clay Adsorption State (IECAS)Fifty millilitres of 50 gL ammonium citrate was added tothe remained residue after the gold extraction of WSS andthe subsequent operations were the same as methods I andII of Section 251 respectively

Table 1 Instrument operating parameters

Parameter SettingXRFInitialization element AgInitialization channel 2210Tube current 250 μATube voltage 40 kVCounting rate 1Vacuum time 25 sMeasure time 100 sReplicates 3Flame AASElement AuWavelength 2428 nmSpectral bandwidth 04 nmLamp current 20mAFilter coefficient 06Integration time 3 sBurner height 6mmFlame type Air-C2H2

Graphite furnace AASElement AuWavelength 2428 nmSpectral bandwidth 04 nmLamp current 40mAFilter coefficient 01Integration time 3 sInjection volume 20 μLMeasurement methods Peak areaXRF X-ray fluorescence spectrometry AAS atomic absorptionspectrometry

Journal of Analytical Methods in Chemistry 3

253 Organic Matter Bound State (OMBS) Fifty millilitresof 4 gL NaOH-40 gL Na4P2O7 mixed solution was added tothe remained residue after the gold extraction of IECAS andthe subsequent operations were the same as methods I and IIof Section 251 respectively

254 Iron-Manganese Oxide Bound State (IMOBS) Fiftymillilitres of 4 gL 100 gL ammonium citrate-40 gL hy-droxylamine hydrochloride mixed solution was added to theremained residue after the gold extraction of OMBS and thesubsequent operations were the same as methods I and II ofSection 251 respectively

255 Naked or Seminaked State (NSNS) Fifty millilitres of5 gL I2-15 gL KI mixed solution was added to the remainedresidue after the gold extraction of IMOBS and the sub-sequent operations were the same as methods I and II ofSection 251 respectively

256 Carbonate Bound State (CBS) Fifty millilitres of4molL HAc was added to the remained residue after thegold extraction of NSNS and the subsequent operationswere the same as methods I and II of Section 251respectively

257 Sulfide Bound State (SBS) Fifty millilitres of 5mLLBr2-100 gL NaCl mixed solution was added to the remainedresidue after the gold extraction of CBS and the subsequentoperations were the same as methods I and II of Section251 respectively

258 Insoluble Silicate State (ISS) Methods I and II 50mLof 50 aqua regia and 10mLHF were added to the remainedresidue after the gold extraction of SBS and the subsequentoperations were the same as the experimental procedure oftotal gold above respectively

26CalibrationCurves Under the optimal conditions of theinstrument in Table 1 two series of calibration curves wereestablished separately with five concentrations of goldstandard solutions and a blank Curve I ranging from 0to 10 μgmL for flame AAS was y 00017 + 00522x witha correlation coefficient of 09998 and curve II rangingfrom 0 to 50 ngmL for graphite furnace AAS wasy 00003 + 00022x with a correlation coefficient of 09996which indicated that a good linear regression was establishedbetween the absorbances and the concentrations

3 Results and Discussion

31 Validation of Analytical Methods e accuracy andprecision requirements of analytical methods can be vali-dated by separately calculating the logarithmic deviation(Δ logC) and relative standard deviation (RSD) between themeasured value and the standard of the CRMe content ofmain constant and trace elements in CRMs GBW07105 andGBW07309 by XRF is listed in Table S1 the total goldcontent of CRMs GBW7247a and GBW07298a by AAS isshown in Table S2 and the relevant quality control pa-rameters Δ logC and RSD could be evaluated from thefollowing equations

Δ lgC (GBW) lgCminus

i minus lgCs

11138681113868111386811138681113868

11138681113868111386811138681113868

RSD (GBW)

1113936ni1 Ci minusCs( 1113857

2(nminus 1)

1113969

Cs

times 100

(1)

where n 5 is the number of parallel experiments Cs is thenational standard value of the CRM and Ci and Ci denotethe single and mean measured value of the CRMrespectively

In Tables S1 and S2 the Δ logC values were in the rangeof 016ndash252 and the RSDs were all less than 680 edetection limits estimated as three times the standard de-viation of the blank were 0002 μgmL and 0012 ngmL forflame and graphite furnace AAS respectively According tothe requirements of the geological and mineral industrystandard DZT0011-2015 of the Peoplersquos Republic of Chinathe detection limits of flame and graphite furnace AAS werelower than those required by the standard and the ΔlogCand RSD values of four CRMs were much smaller than thestandard monitoring limits ese demonstrated that theaccuracy and precision of the experimental method werehigh and satisfied the detection requirements

32 Constant and Trace Element Content Combined withthe geological characteristics of the Laozuoshan gold de-posit the main constant elements Al Ca Fe K Mg Na andSi (expressed by oxide) and trace elements Co Cu Mn NiPb Sn and Zn of the sample were determined by XRF andthe results are shown in Tables S3 and 3 In the Laozuoshangold mine the main ore minerals were arsenopyrite pyr-rhotite pyrite and chalcopyrite and the major gangueminerals were mainly quartz diopside and calcite themeasurement results were clearly related to these geologicaldata Among them the rock ore sample LZY01 containedsulfide quartz vein and its Fe Cu Pb and Co contents wereobviously high LZY02 was granulite its main mineral was

Table 2 Heating program for graphite furnace

Step Temperature (degC) Heating time (s) Holding time (s) Internal gas flow (mLmin)Dry 110 10 10 200Ashing 600 10 15 200Atomization 1800 0 3 0Exclusion 1900 1 2 200

4 Journal of Analytical Methods in Chemistry

quartz and feldspar and its Si content was high LZY03 hadremarkable characteristics of brass mineralization its Cucontent was the highest among the six samples and thecontent of other metal elements was also high LZY04 withno obvious high content elements was a rock sample in thelater stage of mineralization LZY05 was an altered rocksample with a certain degree of quartzification duringmineralization and its Si content was high e sedimentsample LZS01 was collected from the upstream river sandnear the original gold mining field its Si content was highand its Fe Cu Co and Mn contents were low Based on theabove element content information it was preliminarilypredicted that the gold in the sample mainly existed in theSBS the gold content of LZY01 and LZY03 would be higherthan that of others and the gold content in the sedimentmight be lower than that in the rock ore

33 Total Gold Content e measurement results of thetotal gold in the sample by AAS are shown in Tables S4and 4 e total gold content from high to low wasLZY01 gt LZY03gt LZY02gt LZY04gt LZY05gt LZS01 whichmet the expectation of gold-related elements above andfurther indicated that gold was enriched in sulfide quartzveins e gold in the sediment was derived from the debrisformed by the weathering and erosion of the primary rockbut the tiny gold particles were carried away by water flowso the gold content of the sediment was lower than that ofthe rock ore

34 Comparison of Phase Analysis Results e gold contentof each chemical phase in the sample was determined byAAS the weighted value (the sum of eight phase goldcontents) the percentage (the ratio of the phase goldcontent to the weighted value) and the leaching rate (theratio of the weighted value to the total content) werecalculated and all the results are listed in Tables S5 S6 and5 For more intuitive analysis and discussion of relevantdata a histogram for the percentage of gold in eachchemical phase was plotted in Figure 1 Comparing the

extraction effect of methods I and II for gold in eachchemical phase two common points were found (1) epercentages of WSS IECAS IMOBS and NSNS were lowand their maximum value did not exceed 2 which in-dicated that these phase states contained less gold (2) egold percentage of ISS in LZY01 and LZY03 was close to50 due to the inclusion of sulfide quartz veins Except forabove common points there were significant differencesbetween the two methods in Figure 1 For all the samplesthe gold content of OMBS obtained by ultrasonic centri-fugation was much higher than that by cyclotron oscilla-tion and the gold content of SBS extracted by cyclotronoscillation was much more than that by ultrasonic cen-trifugation e average percentage of gold in OMBSextracted by ultrasonic centrifugation was up to 6724and the average percentage of gold in SBS extracted bycyclotron oscillation was up to 6237 Moreover the goldcontent of CBS extracted by cyclotron oscillation was alsolarger than that by ultrasonic centrifugation Since thegold-bearing minerals in the Laozuoshan gold mining areawere mainly arsenopyrite pyrrhotite pyrite and chalco-pyrite and the content of sulfide in samples was high thusthe gold extraction result of each chemical phase by cy-clotron oscillation method was more in line with actualgeological conditions When extracting gold in OMBSultrasound would accelerate the internal motion and de-polymerization of molecules which might lead to the earlyrelease of the subsequent gold in CBS and SBS

In addition the gold content of SBS in sedimentsamples was the highest indicating that the sedimentsystem was affected by the primary halo and its main phasecomposition was consistent with the mineral informationin the mining area us the gold content and phase be-havior of sediments could be used to preliminarily predictthe rock and ore conditions in the corresponding mining

Table 3 e content of main constant and trace elements

Constant element (unit 10minus2)Sample Al2O3 CaO Fe2O3 K2O MgO Na2O SiO2

LZY01 3140 7598 34367 0188 0586 2213 44198LZY02 8916 14113 9429 1693 2472 0201 58545LZY03 7945 20719 8677 0166 1746 0668 47335LZY04 8062 15368 10244 2061 2182 0292 56328LZY05 12504 9485 3513 1600 1136 1968 61755LZS01 11318 1524 1620 3443 0431 2457 63061

Trace element (unit 10minus6)Sample Co Cu Mn Ni Pb Sn ZnLZY01 255089 900836 1055870 48409 39484 0607 133309LZY02 19689 120047 2003167 30235 7462 0826 160777LZY03 18392 1856429 1848804 11438 14410 0742 134596LZY04 20457 243509 1973857 20027 4505 0784 143916LZY05 6162 157230 554794 4761 13303 1757 24905LZS01 1475 26164 117641 2562 48004 0052 297242

Table 4 Analysis results of total gold

Sample LZY01 LZY02 LZY03 LZY04 LZY05 LZS01Content (10minus6) 46985 3980 26060 1840 1490 0176

Journal of Analytical Methods in Chemistry 5

areas analyze and deduce the hard-to-obtain medium withthe easily obtained sampling medium estimate the deepmineral information with the aid of shallow source in-formation and then provide some theoretical guidance forthe exploration of concealed gold deposits and the de-lineation of gold anomalies

Comparing the gold leaching rates of the two methods inTable 5 the average leaching rate of ultrasonic centrifugationand cyclotron oscillation was 10563 and 9659 re-spectively e cyclotron oscillation method had a betterleaching effect on gold since its leaching rate was closer to100 e power and vibration frequency of method I weremuch higher than those of method II but its extractionefficiency was not as good asmethod II At the same time thehigh power and high frequency vibration of method I alsoled to the enhanced cavitation and the solution was easy torise to high temperature so the temperature needed to bestrictly monitored and adjusted during the experimentprocess which increased the complexity of the experimentintroduced more errors and made the measurement resultsdeviate from the geological conditions While the experi-mental procedure of method II was simple and easy theerror was relatively reduced so the cyclotron oscillationmethod had higher leaching ability and efficiency for goldand its phase analysis result was more in line with the XRFdata and the actual geological information Furthermoreultrasound would cause a certain degree of noise pollution

100

80

60

40

20

0

Percentage

I II I II I II I II I II I IILZY01 LZY02 LZY03 LZY04 LZY05 LZS01

ISSIMOBSSBSOMBS

CBSIECASNSNSWSS

Figure 1 e histogram for the percentage of gold in each chemicalphase (I ultrasonic centrifugation II cyclotron oscillation WSSwater-soluble state IECAS ion exchange and clay adsorption stateOMBS organic matter bound state IMOBS iron-manganese oxidebound state NSNS naked or seminaked state CBS carbonate boundstate SBS sulfide bound state ISS insoluble silicate state)

Table 5 Analysis results of phase gold

Sample Method WSS IECAS OMBS IMOBS NSNS CBS SBS ISS Weighted value Leaching rate

LZY01

I 0211 0222 21856 0024 0213 0215 0272 21585 44598 9492(047) (050) (4901) (005) (048) (048) (061) (4840)

II 0224 0238 0240 0026 0216 0384 22261 21572 45161 9612(050) (053) (053) (006) (048) (085) (4929) (4777)

LZY02

I 0000 0019 4456 0002 0011 0005 0036 0065 4594 11543(000) (041) (9700) (004) (024) (011) (078) (141)

II 0006 0006 0051 0007 0003 0032 3079 0605 3789 9520(016) (016) (135) (018) (008) (084) (8126) (1597)

LZY03

I 0118 0112 12906 0015 0133 0031 0158 11439 24912 9560(047) (045) (5181) (006) (053) (012) (063) (4592)

II 0125 0194 1163 0014 0115 0792 11153 11817 25373 9736(049) (076) (458) (006) (045) (312) (4396) (4657)

LZY04

I 0000 0012 2105 0001 0000 0003 0110 0109 2340 12717(000) (051) (8996) (004) (000) (013) (470) (466)

II 0000 0019 0203 0003 0000 0041 1113 0180 1559 8473(000) (122) (1302) (019) (000) (263) (7139) (1155)

LZY05

I 0000 0019 1566 0002 0000 0003 0016 0004 1610 10805(000) (118) (9727) (012) (000) (019) (099) (025)

II 0000 0006 0213 0001 0000 0042 1129 0046 1437 9644(000) (042) (1482) (007) (000) (292) (7857) (320)

LZS01

I 0000 0000 0030 0010 0035 0006 0072 0010 0163 9261(000) (000) (1840) (613) (2147) (368) (4417) (613)

II 0000 0006 0022 0002 0000 0023 0096 0044 0193 10966(000) (311) (1140) (104) (000) (1192) (4974) (2280)

I ultrasonic centrifugation II cyclotron oscillation WSS water-soluble state IECAS ion exchange and clay adsorption state OMBS organic matterbound state IMOBS iron-manganese oxide bound state NSNS naked or seminaked state CBS carbonate bound state SBS sulfide bound state ISSinsoluble silicate state Among the eight phase states the value outside the parentheses is the content of gold in each phase and the unit is 10minus6 the valuein parentheses is the ratio of the phase gold content to the weighted value and the unit is e weighted value is the sum of the eight phase gold contentsand the unit is 10minus6 the leaching rate is the ratio of the weighted value to the total content and the unit is

6 Journal of Analytical Methods in Chemistry

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

253 Organic Matter Bound State (OMBS) Fifty millilitresof 4 gL NaOH-40 gL Na4P2O7 mixed solution was added tothe remained residue after the gold extraction of IECAS andthe subsequent operations were the same as methods I and IIof Section 251 respectively

254 Iron-Manganese Oxide Bound State (IMOBS) Fiftymillilitres of 4 gL 100 gL ammonium citrate-40 gL hy-droxylamine hydrochloride mixed solution was added to theremained residue after the gold extraction of OMBS and thesubsequent operations were the same as methods I and II ofSection 251 respectively

255 Naked or Seminaked State (NSNS) Fifty millilitres of5 gL I2-15 gL KI mixed solution was added to the remainedresidue after the gold extraction of IMOBS and the sub-sequent operations were the same as methods I and II ofSection 251 respectively

256 Carbonate Bound State (CBS) Fifty millilitres of4molL HAc was added to the remained residue after thegold extraction of NSNS and the subsequent operationswere the same as methods I and II of Section 251respectively

257 Sulfide Bound State (SBS) Fifty millilitres of 5mLLBr2-100 gL NaCl mixed solution was added to the remainedresidue after the gold extraction of CBS and the subsequentoperations were the same as methods I and II of Section251 respectively

258 Insoluble Silicate State (ISS) Methods I and II 50mLof 50 aqua regia and 10mLHF were added to the remainedresidue after the gold extraction of SBS and the subsequentoperations were the same as the experimental procedure oftotal gold above respectively

26CalibrationCurves Under the optimal conditions of theinstrument in Table 1 two series of calibration curves wereestablished separately with five concentrations of goldstandard solutions and a blank Curve I ranging from 0to 10 μgmL for flame AAS was y 00017 + 00522x witha correlation coefficient of 09998 and curve II rangingfrom 0 to 50 ngmL for graphite furnace AAS wasy 00003 + 00022x with a correlation coefficient of 09996which indicated that a good linear regression was establishedbetween the absorbances and the concentrations

3 Results and Discussion

31 Validation of Analytical Methods e accuracy andprecision requirements of analytical methods can be vali-dated by separately calculating the logarithmic deviation(Δ logC) and relative standard deviation (RSD) between themeasured value and the standard of the CRMe content ofmain constant and trace elements in CRMs GBW07105 andGBW07309 by XRF is listed in Table S1 the total goldcontent of CRMs GBW7247a and GBW07298a by AAS isshown in Table S2 and the relevant quality control pa-rameters Δ logC and RSD could be evaluated from thefollowing equations

Δ lgC (GBW) lgCminus

i minus lgCs

11138681113868111386811138681113868

11138681113868111386811138681113868

RSD (GBW)

1113936ni1 Ci minusCs( 1113857

2(nminus 1)

1113969

Cs

times 100

(1)

where n 5 is the number of parallel experiments Cs is thenational standard value of the CRM and Ci and Ci denotethe single and mean measured value of the CRMrespectively

In Tables S1 and S2 the Δ logC values were in the rangeof 016ndash252 and the RSDs were all less than 680 edetection limits estimated as three times the standard de-viation of the blank were 0002 μgmL and 0012 ngmL forflame and graphite furnace AAS respectively According tothe requirements of the geological and mineral industrystandard DZT0011-2015 of the Peoplersquos Republic of Chinathe detection limits of flame and graphite furnace AAS werelower than those required by the standard and the ΔlogCand RSD values of four CRMs were much smaller than thestandard monitoring limits ese demonstrated that theaccuracy and precision of the experimental method werehigh and satisfied the detection requirements

32 Constant and Trace Element Content Combined withthe geological characteristics of the Laozuoshan gold de-posit the main constant elements Al Ca Fe K Mg Na andSi (expressed by oxide) and trace elements Co Cu Mn NiPb Sn and Zn of the sample were determined by XRF andthe results are shown in Tables S3 and 3 In the Laozuoshangold mine the main ore minerals were arsenopyrite pyr-rhotite pyrite and chalcopyrite and the major gangueminerals were mainly quartz diopside and calcite themeasurement results were clearly related to these geologicaldata Among them the rock ore sample LZY01 containedsulfide quartz vein and its Fe Cu Pb and Co contents wereobviously high LZY02 was granulite its main mineral was

Table 2 Heating program for graphite furnace

Step Temperature (degC) Heating time (s) Holding time (s) Internal gas flow (mLmin)Dry 110 10 10 200Ashing 600 10 15 200Atomization 1800 0 3 0Exclusion 1900 1 2 200

4 Journal of Analytical Methods in Chemistry

quartz and feldspar and its Si content was high LZY03 hadremarkable characteristics of brass mineralization its Cucontent was the highest among the six samples and thecontent of other metal elements was also high LZY04 withno obvious high content elements was a rock sample in thelater stage of mineralization LZY05 was an altered rocksample with a certain degree of quartzification duringmineralization and its Si content was high e sedimentsample LZS01 was collected from the upstream river sandnear the original gold mining field its Si content was highand its Fe Cu Co and Mn contents were low Based on theabove element content information it was preliminarilypredicted that the gold in the sample mainly existed in theSBS the gold content of LZY01 and LZY03 would be higherthan that of others and the gold content in the sedimentmight be lower than that in the rock ore

33 Total Gold Content e measurement results of thetotal gold in the sample by AAS are shown in Tables S4and 4 e total gold content from high to low wasLZY01 gt LZY03gt LZY02gt LZY04gt LZY05gt LZS01 whichmet the expectation of gold-related elements above andfurther indicated that gold was enriched in sulfide quartzveins e gold in the sediment was derived from the debrisformed by the weathering and erosion of the primary rockbut the tiny gold particles were carried away by water flowso the gold content of the sediment was lower than that ofthe rock ore

34 Comparison of Phase Analysis Results e gold contentof each chemical phase in the sample was determined byAAS the weighted value (the sum of eight phase goldcontents) the percentage (the ratio of the phase goldcontent to the weighted value) and the leaching rate (theratio of the weighted value to the total content) werecalculated and all the results are listed in Tables S5 S6 and5 For more intuitive analysis and discussion of relevantdata a histogram for the percentage of gold in eachchemical phase was plotted in Figure 1 Comparing the

extraction effect of methods I and II for gold in eachchemical phase two common points were found (1) epercentages of WSS IECAS IMOBS and NSNS were lowand their maximum value did not exceed 2 which in-dicated that these phase states contained less gold (2) egold percentage of ISS in LZY01 and LZY03 was close to50 due to the inclusion of sulfide quartz veins Except forabove common points there were significant differencesbetween the two methods in Figure 1 For all the samplesthe gold content of OMBS obtained by ultrasonic centri-fugation was much higher than that by cyclotron oscilla-tion and the gold content of SBS extracted by cyclotronoscillation was much more than that by ultrasonic cen-trifugation e average percentage of gold in OMBSextracted by ultrasonic centrifugation was up to 6724and the average percentage of gold in SBS extracted bycyclotron oscillation was up to 6237 Moreover the goldcontent of CBS extracted by cyclotron oscillation was alsolarger than that by ultrasonic centrifugation Since thegold-bearing minerals in the Laozuoshan gold mining areawere mainly arsenopyrite pyrrhotite pyrite and chalco-pyrite and the content of sulfide in samples was high thusthe gold extraction result of each chemical phase by cy-clotron oscillation method was more in line with actualgeological conditions When extracting gold in OMBSultrasound would accelerate the internal motion and de-polymerization of molecules which might lead to the earlyrelease of the subsequent gold in CBS and SBS

In addition the gold content of SBS in sedimentsamples was the highest indicating that the sedimentsystem was affected by the primary halo and its main phasecomposition was consistent with the mineral informationin the mining area us the gold content and phase be-havior of sediments could be used to preliminarily predictthe rock and ore conditions in the corresponding mining

Table 3 e content of main constant and trace elements

Constant element (unit 10minus2)Sample Al2O3 CaO Fe2O3 K2O MgO Na2O SiO2

LZY01 3140 7598 34367 0188 0586 2213 44198LZY02 8916 14113 9429 1693 2472 0201 58545LZY03 7945 20719 8677 0166 1746 0668 47335LZY04 8062 15368 10244 2061 2182 0292 56328LZY05 12504 9485 3513 1600 1136 1968 61755LZS01 11318 1524 1620 3443 0431 2457 63061

Trace element (unit 10minus6)Sample Co Cu Mn Ni Pb Sn ZnLZY01 255089 900836 1055870 48409 39484 0607 133309LZY02 19689 120047 2003167 30235 7462 0826 160777LZY03 18392 1856429 1848804 11438 14410 0742 134596LZY04 20457 243509 1973857 20027 4505 0784 143916LZY05 6162 157230 554794 4761 13303 1757 24905LZS01 1475 26164 117641 2562 48004 0052 297242

Table 4 Analysis results of total gold

Sample LZY01 LZY02 LZY03 LZY04 LZY05 LZS01Content (10minus6) 46985 3980 26060 1840 1490 0176

Journal of Analytical Methods in Chemistry 5

areas analyze and deduce the hard-to-obtain medium withthe easily obtained sampling medium estimate the deepmineral information with the aid of shallow source in-formation and then provide some theoretical guidance forthe exploration of concealed gold deposits and the de-lineation of gold anomalies

Comparing the gold leaching rates of the two methods inTable 5 the average leaching rate of ultrasonic centrifugationand cyclotron oscillation was 10563 and 9659 re-spectively e cyclotron oscillation method had a betterleaching effect on gold since its leaching rate was closer to100 e power and vibration frequency of method I weremuch higher than those of method II but its extractionefficiency was not as good asmethod II At the same time thehigh power and high frequency vibration of method I alsoled to the enhanced cavitation and the solution was easy torise to high temperature so the temperature needed to bestrictly monitored and adjusted during the experimentprocess which increased the complexity of the experimentintroduced more errors and made the measurement resultsdeviate from the geological conditions While the experi-mental procedure of method II was simple and easy theerror was relatively reduced so the cyclotron oscillationmethod had higher leaching ability and efficiency for goldand its phase analysis result was more in line with the XRFdata and the actual geological information Furthermoreultrasound would cause a certain degree of noise pollution

100

80

60

40

20

0

Percentage

I II I II I II I II I II I IILZY01 LZY02 LZY03 LZY04 LZY05 LZS01

ISSIMOBSSBSOMBS

CBSIECASNSNSWSS

Figure 1 e histogram for the percentage of gold in each chemicalphase (I ultrasonic centrifugation II cyclotron oscillation WSSwater-soluble state IECAS ion exchange and clay adsorption stateOMBS organic matter bound state IMOBS iron-manganese oxidebound state NSNS naked or seminaked state CBS carbonate boundstate SBS sulfide bound state ISS insoluble silicate state)

Table 5 Analysis results of phase gold

Sample Method WSS IECAS OMBS IMOBS NSNS CBS SBS ISS Weighted value Leaching rate

LZY01

I 0211 0222 21856 0024 0213 0215 0272 21585 44598 9492(047) (050) (4901) (005) (048) (048) (061) (4840)

II 0224 0238 0240 0026 0216 0384 22261 21572 45161 9612(050) (053) (053) (006) (048) (085) (4929) (4777)

LZY02

I 0000 0019 4456 0002 0011 0005 0036 0065 4594 11543(000) (041) (9700) (004) (024) (011) (078) (141)

II 0006 0006 0051 0007 0003 0032 3079 0605 3789 9520(016) (016) (135) (018) (008) (084) (8126) (1597)

LZY03

I 0118 0112 12906 0015 0133 0031 0158 11439 24912 9560(047) (045) (5181) (006) (053) (012) (063) (4592)

II 0125 0194 1163 0014 0115 0792 11153 11817 25373 9736(049) (076) (458) (006) (045) (312) (4396) (4657)

LZY04

I 0000 0012 2105 0001 0000 0003 0110 0109 2340 12717(000) (051) (8996) (004) (000) (013) (470) (466)

II 0000 0019 0203 0003 0000 0041 1113 0180 1559 8473(000) (122) (1302) (019) (000) (263) (7139) (1155)

LZY05

I 0000 0019 1566 0002 0000 0003 0016 0004 1610 10805(000) (118) (9727) (012) (000) (019) (099) (025)

II 0000 0006 0213 0001 0000 0042 1129 0046 1437 9644(000) (042) (1482) (007) (000) (292) (7857) (320)

LZS01

I 0000 0000 0030 0010 0035 0006 0072 0010 0163 9261(000) (000) (1840) (613) (2147) (368) (4417) (613)

II 0000 0006 0022 0002 0000 0023 0096 0044 0193 10966(000) (311) (1140) (104) (000) (1192) (4974) (2280)

I ultrasonic centrifugation II cyclotron oscillation WSS water-soluble state IECAS ion exchange and clay adsorption state OMBS organic matterbound state IMOBS iron-manganese oxide bound state NSNS naked or seminaked state CBS carbonate bound state SBS sulfide bound state ISSinsoluble silicate state Among the eight phase states the value outside the parentheses is the content of gold in each phase and the unit is 10minus6 the valuein parentheses is the ratio of the phase gold content to the weighted value and the unit is e weighted value is the sum of the eight phase gold contentsand the unit is 10minus6 the leaching rate is the ratio of the weighted value to the total content and the unit is

6 Journal of Analytical Methods in Chemistry

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

quartz and feldspar and its Si content was high LZY03 hadremarkable characteristics of brass mineralization its Cucontent was the highest among the six samples and thecontent of other metal elements was also high LZY04 withno obvious high content elements was a rock sample in thelater stage of mineralization LZY05 was an altered rocksample with a certain degree of quartzification duringmineralization and its Si content was high e sedimentsample LZS01 was collected from the upstream river sandnear the original gold mining field its Si content was highand its Fe Cu Co and Mn contents were low Based on theabove element content information it was preliminarilypredicted that the gold in the sample mainly existed in theSBS the gold content of LZY01 and LZY03 would be higherthan that of others and the gold content in the sedimentmight be lower than that in the rock ore

33 Total Gold Content e measurement results of thetotal gold in the sample by AAS are shown in Tables S4and 4 e total gold content from high to low wasLZY01 gt LZY03gt LZY02gt LZY04gt LZY05gt LZS01 whichmet the expectation of gold-related elements above andfurther indicated that gold was enriched in sulfide quartzveins e gold in the sediment was derived from the debrisformed by the weathering and erosion of the primary rockbut the tiny gold particles were carried away by water flowso the gold content of the sediment was lower than that ofthe rock ore

34 Comparison of Phase Analysis Results e gold contentof each chemical phase in the sample was determined byAAS the weighted value (the sum of eight phase goldcontents) the percentage (the ratio of the phase goldcontent to the weighted value) and the leaching rate (theratio of the weighted value to the total content) werecalculated and all the results are listed in Tables S5 S6 and5 For more intuitive analysis and discussion of relevantdata a histogram for the percentage of gold in eachchemical phase was plotted in Figure 1 Comparing the

extraction effect of methods I and II for gold in eachchemical phase two common points were found (1) epercentages of WSS IECAS IMOBS and NSNS were lowand their maximum value did not exceed 2 which in-dicated that these phase states contained less gold (2) egold percentage of ISS in LZY01 and LZY03 was close to50 due to the inclusion of sulfide quartz veins Except forabove common points there were significant differencesbetween the two methods in Figure 1 For all the samplesthe gold content of OMBS obtained by ultrasonic centri-fugation was much higher than that by cyclotron oscilla-tion and the gold content of SBS extracted by cyclotronoscillation was much more than that by ultrasonic cen-trifugation e average percentage of gold in OMBSextracted by ultrasonic centrifugation was up to 6724and the average percentage of gold in SBS extracted bycyclotron oscillation was up to 6237 Moreover the goldcontent of CBS extracted by cyclotron oscillation was alsolarger than that by ultrasonic centrifugation Since thegold-bearing minerals in the Laozuoshan gold mining areawere mainly arsenopyrite pyrrhotite pyrite and chalco-pyrite and the content of sulfide in samples was high thusthe gold extraction result of each chemical phase by cy-clotron oscillation method was more in line with actualgeological conditions When extracting gold in OMBSultrasound would accelerate the internal motion and de-polymerization of molecules which might lead to the earlyrelease of the subsequent gold in CBS and SBS

In addition the gold content of SBS in sedimentsamples was the highest indicating that the sedimentsystem was affected by the primary halo and its main phasecomposition was consistent with the mineral informationin the mining area us the gold content and phase be-havior of sediments could be used to preliminarily predictthe rock and ore conditions in the corresponding mining

Table 3 e content of main constant and trace elements

Constant element (unit 10minus2)Sample Al2O3 CaO Fe2O3 K2O MgO Na2O SiO2

LZY01 3140 7598 34367 0188 0586 2213 44198LZY02 8916 14113 9429 1693 2472 0201 58545LZY03 7945 20719 8677 0166 1746 0668 47335LZY04 8062 15368 10244 2061 2182 0292 56328LZY05 12504 9485 3513 1600 1136 1968 61755LZS01 11318 1524 1620 3443 0431 2457 63061

Trace element (unit 10minus6)Sample Co Cu Mn Ni Pb Sn ZnLZY01 255089 900836 1055870 48409 39484 0607 133309LZY02 19689 120047 2003167 30235 7462 0826 160777LZY03 18392 1856429 1848804 11438 14410 0742 134596LZY04 20457 243509 1973857 20027 4505 0784 143916LZY05 6162 157230 554794 4761 13303 1757 24905LZS01 1475 26164 117641 2562 48004 0052 297242

Table 4 Analysis results of total gold

Sample LZY01 LZY02 LZY03 LZY04 LZY05 LZS01Content (10minus6) 46985 3980 26060 1840 1490 0176

Journal of Analytical Methods in Chemistry 5

areas analyze and deduce the hard-to-obtain medium withthe easily obtained sampling medium estimate the deepmineral information with the aid of shallow source in-formation and then provide some theoretical guidance forthe exploration of concealed gold deposits and the de-lineation of gold anomalies

Comparing the gold leaching rates of the two methods inTable 5 the average leaching rate of ultrasonic centrifugationand cyclotron oscillation was 10563 and 9659 re-spectively e cyclotron oscillation method had a betterleaching effect on gold since its leaching rate was closer to100 e power and vibration frequency of method I weremuch higher than those of method II but its extractionefficiency was not as good asmethod II At the same time thehigh power and high frequency vibration of method I alsoled to the enhanced cavitation and the solution was easy torise to high temperature so the temperature needed to bestrictly monitored and adjusted during the experimentprocess which increased the complexity of the experimentintroduced more errors and made the measurement resultsdeviate from the geological conditions While the experi-mental procedure of method II was simple and easy theerror was relatively reduced so the cyclotron oscillationmethod had higher leaching ability and efficiency for goldand its phase analysis result was more in line with the XRFdata and the actual geological information Furthermoreultrasound would cause a certain degree of noise pollution

100

80

60

40

20

0

Percentage

I II I II I II I II I II I IILZY01 LZY02 LZY03 LZY04 LZY05 LZS01

ISSIMOBSSBSOMBS

CBSIECASNSNSWSS

Figure 1 e histogram for the percentage of gold in each chemicalphase (I ultrasonic centrifugation II cyclotron oscillation WSSwater-soluble state IECAS ion exchange and clay adsorption stateOMBS organic matter bound state IMOBS iron-manganese oxidebound state NSNS naked or seminaked state CBS carbonate boundstate SBS sulfide bound state ISS insoluble silicate state)

Table 5 Analysis results of phase gold

Sample Method WSS IECAS OMBS IMOBS NSNS CBS SBS ISS Weighted value Leaching rate

LZY01

I 0211 0222 21856 0024 0213 0215 0272 21585 44598 9492(047) (050) (4901) (005) (048) (048) (061) (4840)

II 0224 0238 0240 0026 0216 0384 22261 21572 45161 9612(050) (053) (053) (006) (048) (085) (4929) (4777)

LZY02

I 0000 0019 4456 0002 0011 0005 0036 0065 4594 11543(000) (041) (9700) (004) (024) (011) (078) (141)

II 0006 0006 0051 0007 0003 0032 3079 0605 3789 9520(016) (016) (135) (018) (008) (084) (8126) (1597)

LZY03

I 0118 0112 12906 0015 0133 0031 0158 11439 24912 9560(047) (045) (5181) (006) (053) (012) (063) (4592)

II 0125 0194 1163 0014 0115 0792 11153 11817 25373 9736(049) (076) (458) (006) (045) (312) (4396) (4657)

LZY04

I 0000 0012 2105 0001 0000 0003 0110 0109 2340 12717(000) (051) (8996) (004) (000) (013) (470) (466)

II 0000 0019 0203 0003 0000 0041 1113 0180 1559 8473(000) (122) (1302) (019) (000) (263) (7139) (1155)

LZY05

I 0000 0019 1566 0002 0000 0003 0016 0004 1610 10805(000) (118) (9727) (012) (000) (019) (099) (025)

II 0000 0006 0213 0001 0000 0042 1129 0046 1437 9644(000) (042) (1482) (007) (000) (292) (7857) (320)

LZS01

I 0000 0000 0030 0010 0035 0006 0072 0010 0163 9261(000) (000) (1840) (613) (2147) (368) (4417) (613)

II 0000 0006 0022 0002 0000 0023 0096 0044 0193 10966(000) (311) (1140) (104) (000) (1192) (4974) (2280)

I ultrasonic centrifugation II cyclotron oscillation WSS water-soluble state IECAS ion exchange and clay adsorption state OMBS organic matterbound state IMOBS iron-manganese oxide bound state NSNS naked or seminaked state CBS carbonate bound state SBS sulfide bound state ISSinsoluble silicate state Among the eight phase states the value outside the parentheses is the content of gold in each phase and the unit is 10minus6 the valuein parentheses is the ratio of the phase gold content to the weighted value and the unit is e weighted value is the sum of the eight phase gold contentsand the unit is 10minus6 the leaching rate is the ratio of the weighted value to the total content and the unit is

6 Journal of Analytical Methods in Chemistry

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

areas analyze and deduce the hard-to-obtain medium withthe easily obtained sampling medium estimate the deepmineral information with the aid of shallow source in-formation and then provide some theoretical guidance forthe exploration of concealed gold deposits and the de-lineation of gold anomalies

Comparing the gold leaching rates of the two methods inTable 5 the average leaching rate of ultrasonic centrifugationand cyclotron oscillation was 10563 and 9659 re-spectively e cyclotron oscillation method had a betterleaching effect on gold since its leaching rate was closer to100 e power and vibration frequency of method I weremuch higher than those of method II but its extractionefficiency was not as good asmethod II At the same time thehigh power and high frequency vibration of method I alsoled to the enhanced cavitation and the solution was easy torise to high temperature so the temperature needed to bestrictly monitored and adjusted during the experimentprocess which increased the complexity of the experimentintroduced more errors and made the measurement resultsdeviate from the geological conditions While the experi-mental procedure of method II was simple and easy theerror was relatively reduced so the cyclotron oscillationmethod had higher leaching ability and efficiency for goldand its phase analysis result was more in line with the XRFdata and the actual geological information Furthermoreultrasound would cause a certain degree of noise pollution

100

80

60

40

20

0

Percentage

I II I II I II I II I II I IILZY01 LZY02 LZY03 LZY04 LZY05 LZS01

ISSIMOBSSBSOMBS

CBSIECASNSNSWSS

Figure 1 e histogram for the percentage of gold in each chemicalphase (I ultrasonic centrifugation II cyclotron oscillation WSSwater-soluble state IECAS ion exchange and clay adsorption stateOMBS organic matter bound state IMOBS iron-manganese oxidebound state NSNS naked or seminaked state CBS carbonate boundstate SBS sulfide bound state ISS insoluble silicate state)

Table 5 Analysis results of phase gold

Sample Method WSS IECAS OMBS IMOBS NSNS CBS SBS ISS Weighted value Leaching rate

LZY01

I 0211 0222 21856 0024 0213 0215 0272 21585 44598 9492(047) (050) (4901) (005) (048) (048) (061) (4840)

II 0224 0238 0240 0026 0216 0384 22261 21572 45161 9612(050) (053) (053) (006) (048) (085) (4929) (4777)

LZY02

I 0000 0019 4456 0002 0011 0005 0036 0065 4594 11543(000) (041) (9700) (004) (024) (011) (078) (141)

II 0006 0006 0051 0007 0003 0032 3079 0605 3789 9520(016) (016) (135) (018) (008) (084) (8126) (1597)

LZY03

I 0118 0112 12906 0015 0133 0031 0158 11439 24912 9560(047) (045) (5181) (006) (053) (012) (063) (4592)

II 0125 0194 1163 0014 0115 0792 11153 11817 25373 9736(049) (076) (458) (006) (045) (312) (4396) (4657)

LZY04

I 0000 0012 2105 0001 0000 0003 0110 0109 2340 12717(000) (051) (8996) (004) (000) (013) (470) (466)

II 0000 0019 0203 0003 0000 0041 1113 0180 1559 8473(000) (122) (1302) (019) (000) (263) (7139) (1155)

LZY05

I 0000 0019 1566 0002 0000 0003 0016 0004 1610 10805(000) (118) (9727) (012) (000) (019) (099) (025)

II 0000 0006 0213 0001 0000 0042 1129 0046 1437 9644(000) (042) (1482) (007) (000) (292) (7857) (320)

LZS01

I 0000 0000 0030 0010 0035 0006 0072 0010 0163 9261(000) (000) (1840) (613) (2147) (368) (4417) (613)

II 0000 0006 0022 0002 0000 0023 0096 0044 0193 10966(000) (311) (1140) (104) (000) (1192) (4974) (2280)

I ultrasonic centrifugation II cyclotron oscillation WSS water-soluble state IECAS ion exchange and clay adsorption state OMBS organic matterbound state IMOBS iron-manganese oxide bound state NSNS naked or seminaked state CBS carbonate bound state SBS sulfide bound state ISSinsoluble silicate state Among the eight phase states the value outside the parentheses is the content of gold in each phase and the unit is 10minus6 the valuein parentheses is the ratio of the phase gold content to the weighted value and the unit is e weighted value is the sum of the eight phase gold contentsand the unit is 10minus6 the leaching rate is the ratio of the weighted value to the total content and the unit is

6 Journal of Analytical Methods in Chemistry

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

while the cyclotron oscillation method was greener andmore environmentally friendly

4 Conclusion

To reasonably analyze the chemical phase of gold in geo-logical samples good pretreatment and test methods arenecessary In this work two pretreatment processes of ul-trasonic centrifugation and cyclotron oscillation for theextraction of gold from eight chemical phases are comparedand the gold content is determined by AAS It is found thatthe experiment steps are cumbersome and it is easy tointroduce more errors and cause a certain degree of noisepollution in ultrasonic centrifugation method Whenextracting gold of OMBS ultrasound accelerates the internalmolecular movement and depolymerization and releases thesubsequent gold of CBS and SBS in advance which causesthe high gold content of OMBS and the extraction results tobe inconsistent with the actual situation However the mainphase obtained by cyclotron oscillation method is SBSwhich is consistent with the XRF analysis and the geologicalinformation of the Laozuoshan gold deposit Moreover thecyclotron oscillation has the advantages of simple experi-mental steps relatively low error and high gold leachingefficiency erefore the cyclotron oscillation method is anaccurate and quick pretreatment method which meets thedevelopment requirements of green chemistry and envi-ronmental protection and can be well suited for the de-termination of the chemical phase of gold in geologicalsamples by AAS

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that they have no conflicts of interest

Acknowledgments

is research was supported by the Chinese Academy ofGeological Sciences Project (AS2016P02) Deep-Pene-trating Geochemistry Project (2016YFC0600606 and2016YFC0600600) funded by the State Key Research andDevelopment Program National Natural Science Foun-dation of China (51603083) and Mapping Chemical EarthProject (DD20160116)

Supplementary Materials

Table S1 the measured values of main constant and traceelements for CRMs GBW07105 and GBW07309 by XRFTable S2 the analysis results of total gold for CRMsGBW7247a and GBW07298a by AAS Table S3 the mea-sured values of main constant and trace elements for sixsamples by XRF Table S4 the measured values of total goldfor six samples by AAS Table S5 the measured values ofphase gold for six samples by the ultrasonic centrifugation

method Table S6 the measured values of phase gold for sixsamples by the cyclotron oscillation method (Supplemen-tary Materials)

References

[1] C Wang D Wang J Xu L Ying L Liu and S Liu ldquoApreliminary review of metallogenic regularity of gold depositsin ChinardquoActa Geologica Sinica-English Edition vol 89 no 2pp 632ndash651 2015

[2] V Sheoran A S Sheoran and P Poonia ldquoPhytomining ofgold a reviewrdquo Journal of Geochemical Exploration vol 128pp 42ndash50 2013

[3] S Alim J Vejayan M M Yusoff and A K M Kafi ldquoRecentuses of carbon nanotubes amp gold nanoparticles in electro-chemistry with application in biosensing a reviewrdquo Biosensorsand Bioelectronics vol 121 pp 125ndash136 2018

[4] J G Noel ldquoReview of the properties of gold material forMEMS membrane applicationsrdquo IET Circuits Devices ampSystems vol 10 no 2 pp 156ndash161 2016

[5] K Pyrzynska ldquoSorbent materials for separation and pre-concentration of gold in environmental and geologicalsamples-a reviewrdquo Analytica Chimica Acta vol 741 pp 9ndash142012

[6] W Yang and A S K Hashmi ldquoMechanistic insights into thegold chemistry of allenesrdquo Chemical Society Reviews vol 43no 9 pp 2941ndash2955 2014

[7] C Yeo K Ooi and E Tiekink ldquoGold-based medicine aparadigm shift in anti-cancer therapyrdquo Molecules vol 23no 6 p 1410 2018

[8] G Danscher and A Larsen ldquoEffects of dissolucytotic gold ionson recovering brain lesionsrdquo Histochemistry and Cell Biologyvol 133 no 4 pp 367ndash373 2010

[9] V V Malakhov and I G Vasilyeva ldquoStoichiography andchemical methods of phase analysis of multielement multi-phase compounds and materialsrdquo Russian Chemical Reviewsvol 77 no 4 pp 370ndash392 2008

[10] M Zhang and M L Gong ldquoPhase analysis of trace gold ingeological materialsrdquo Metallurgical Analysis vol 11 no 3pp 1ndash5 1991

[11] Y X Lu and J F Bai ldquoPhase analysis for goldrdquo Rock andMineral Analysis vol 19 no 2 pp 81ndash86 2000

[12] H JWang B Quan and X X Ning ldquoAccurate determinationand development of chemical phase analysis of goldrdquoChemical Analysis Meterage vol 22 no 1 pp 103ndash107 2013

[13] H J Wang ldquoChemical phase analysis of gold in the complexgold ore and its developmentrdquo Gold Science amp Technologyvol 21 no 2 pp 55ndash60 2013

[14] J B Guo J B Liu M Cai and J G Zhu ldquoExploration ofchemical phase analysis of gold ore by selective solventsrdquoAnalysis and Testing Technology and Instruments vol 20no 1 pp 13ndash19 2014

[15] W Y Sun S-J Qi J-L Lu et al ldquoPhase analysis on Au in thesoil of Anba ore block Yangshan gold deposit GansuProvincerdquo Global Geology vol 33 no 1 pp 112ndash119 2014

[16] F Y Fei X J Ma and Z J Qi ldquoChemical phase analysis ofgold in ores from Wulonggou gold mine Qinghai provincerdquoGold vol 36 no 10 pp 82ndash84 2015

[17] D Xue H Wang Y Liu P Shen and J Sun ldquoCytosine-functionalized polyurethane foam and its use as a sorbent forthe determination of gold in geological samplesrdquo AnalyticalMethods vol 8 no 1 pp 29ndash39 2016

Journal of Analytical Methods in Chemistry 7

[18] N-C Choi B-J Kim K Cho S Lee and C-Y Park ldquoMi-crowave pretreatment for thiourea leaching for gold con-centraterdquo Metals vol 7 no 10 p 404 2017

[19] A U Oya Y G Zeynep D Sabahattin K Y Ece andA Adnan ldquoA novel ligand for cloud point extraction todetermine gold content in ore samplesrdquo EnvironmentalChemistry Letters vol 12 no 3 pp 449ndash453 2014

[20] F Sabermahani M A Taher and H Bahrami ldquoSeparationand preconcentration of trace amounts of gold from watersamples prior to determination by flame atomic absorptionspectrometryrdquo Arabian Journal of Chemistry vol 9pp S1700ndashS1705 2016

[21] C Stefano B Silvano R Lorenzo B Simone I Massimo andP Giovanni ldquoSimultaneous determination of gold and pal-ladium via potentiometric titrationrdquo Current AnalyticalChemistry vol 11 no 3 pp 217ndash224 2015

[22] O Sha and X Zhu ldquoDetermination of gold(III) by simplifiedroom-temperature ionic liquid extraction with flame atomicabsorption spectrometryrdquo Analytical Letters vol 47 no 6pp 1052ndash1062 2014

[23] E Yilmaz and M Soylak ldquoSupramolecular solvent micro-extraction of gold prior to its determination by microsampleinjection system coupled with flame atomic absorptionspectrometryrdquo RSC Advances vol 4 no 88 pp 47396ndash474012014

[24] S Zhou N Song X Lv and Q Jia ldquoMagnetic dual task-specific polymeric ionic liquid nanoparticles for preconcen-tration and determination of gold palladium and platinumprior to their quantitation by graphite furnace AASrdquoMicrochimica Acta vol 184 no 9 pp 3497ndash3504 2017

[25] A Z George and N A Konstantinos ldquoe potential of de-sirability function strategy in chemometric optimization ofICP-AES for platinum group elements and goldrdquo CurrentAnalytical Chemistry vol 12 no 2 pp 147ndash158 2016

[26] V Nagaraja M K Kumar and N Giddappa ldquoSpectropho-tometric determination of gold(III) in forensic and phar-maceutical samples and results complemented with ICP AESand EDXRF analysisrdquo Spectrochimica Acta Part A Molecularand Biomolecular Spectroscopy vol 173 pp 407ndash417 2017

[27] D Tao W Guo W Xie L Jin Q Guo and S Hu ldquoRapid andaccurate determination of gold in geological materials by animproved ICP-MS methodrdquo Microchemical Journal vol 135pp 221ndash225 2017

[28] J Liu D Zou X Yang X Cheng and Q Chen ldquoA modifiedpersimmon powder sorbent for selective separation and de-termination of trace gold in geological samples by ICP-MSrdquoAnalytical Methods vol 5 no 23 pp 6774ndash6780 2013

[29] R Dobrowolski A Mroz M Dabrowska and P OlszanskildquoSolid sampling high-resolution continuum source graphitefurnace atomic absorption spectrometry for gold de-termination in geological samples after preconcentration ontocarbon nanotubesrdquo Spectrochimica Acta Part B AtomicSpectroscopy vol 132 pp 13ndash18 2017

[30] R Dobrowolski M Kuryło M Otto and A Mroz ldquoDe-termination of gold in geological materials by carbon slurrysampling graphite furnace atomic absorption spectrometryrdquoTalanta vol 99 pp 750ndash757 2012

[31] C Zeng and L Tang ldquoDetermination of gold by flame atomicabsorption spectrometry with hollow fiber liquid phasemicroextraction using room temperature ionic liquidsrdquoAnalytical Letters vol 46 no 9 pp 1442ndash1453 2013

[32] V Balaram R Mathur M Satyanarayanan et al ldquoA rapidmethod for the determination of gold in rocks ores and othergeological materials by F-AAS and GF-AAS after separation

and preconcentration by DIBK extraction for prospectingstudiesrdquo MAPAN-Journal of Metrology Society of Indiavol 27 no 2 pp 87ndash95 2012

[33] O B Odumo A O Mustapha J P Patel and H K AngeyoldquoMultielemental analysis of migori (southwest Kenya) arti-sanal gold mine ores and sediments by EDX-ray fluorescencetechnique implications of occupational exposure and envi-ronmental impactrdquo Bulletin of Environmental Contaminationand Toxicology vol 86 no 5 pp 484ndash489 2011

[34] M F Gazley J K Vry E du Plessis and M R HandlerldquoApplication of portable X-ray fluorescence analyses tometabasalt stratigraphy Plutonic gold mine Western Aus-traliardquo Journal of Geochemical Exploration vol 110 no 2pp 74ndash80 2011

[35] M Wu L Li J-G Sun and R Yang ldquoGeology geochemistryand geochronology of the Laozuoshan gold deposit Hei-longjiang province Northeast China implications for mul-tiple gold mineralization events and geodynamic settingrdquoCanadian Journal of Earth Sciences vol 55 no 6 pp 604ndash6192018

[36] M F Li S Q Ye Y C Yang et al ldquoGeological and geo-chemical characteristics of Laozuoshan gold deposit in Hei-longjiang and its metallotectonic settingrdquo Global Geologyvol 33 no 3 pp 543ndash555 2014

8 Journal of Analytical Methods in Chemistry

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom