Residual Solvents from Food Packaging Materials

Residual Solvents from Food Packaging Materials

Standards

• TraceCERTTMCertified ReferenceMaterials

• Determinationofthe HydrocarbonOilIndex

• QuantitativeMulti- TargetAnalysisof Mycotoxins

Chromatography

• High-PurityWaterfor IonChromatography

• CertifiedEluent ConcentratesforIC

Spectroscopy

• Spectroscopic ReagentsforUV/VIS

Sensorics • IonSensorsforpHand Hg2+Determination

Titration

• HYDRANAL® MediumK

Analytical Microbiology

• Streptococci

NewProductCorner

• LC-MSSolvents forChiral Chromatography

• NewEnvironmental Standards

Issue3•2007AdvancesinAnalyticalChemistry

Analytix

02

HYDRANAL® Karl Fischer Reagents …..... NewMultimediaGuideCDVersion3.0

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TheAnalytixispublished5timesperyearbySigma-AldrichChemieGmbH,MarComEurope,Industriestrasse25,CH-9471BuchsSG,SwitzerlandPublisher:Sigma-AldrichMarketingCommunicationsEuropePublicationDirector:IngoHaag,PhDEditor:DaveR.vanStaveren,PhD

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Feature Article

04 ResidualSolventsfromFoodPackagingMaterials

Twonewstandardscontaintwenty-fivesolventsofinterestforfoodsafetyandregulation

Standards

06 TraceCERTTM–TraceableCertifiedReference Materials.Part4:Production,Handling andStorageofHigh-PrecisionCalibration Solutions Thisisthefourthinstallmentofaseriesof

articlesonCertifiedReferenceMaterials

09 DeterminationoftheHydrocarbonOil IndexinWater,SoilandSludge Kitsandtestsetsforthechromatographic determinationofhydrocarboncontent

10 HPLC/MS-MSfortheQuantitativeMulti-Target AnalysisofMycotoxins Trichotheceneandothermycotoxinstandards enablereliablequantitation

Chromatography

12 High-PurityWaterforIonChromatographyfromSigma-Aldrich

Dedicatedproduction,detailedtestingandspecialpackagingguaranteehighestqualityforsensitiveanalyses

13 CertifiedEluentConcentratesforIonChromatographyfromSigma-Aldrich

Well-characterizedsolutionsareaconvenienttime-andcost-savingoption

Spectroscopy

14 SpectroscopicReagentsforUV/VISbySigma-Aldrich

Awiderangeofhigh-qualityreagentsforsensitive,quantitativedeterminations

Sensorics

16 Selectophore®Products Sigma-Aldrichintroducestwonewion-sensors

forpH(H+)andHg2+determination

Titration

18 HYDRANAL®MediumK Efficaciousandnon-toxicKarlFischerReagents

forwaterdeterminationinaldehydesandketones

Analytical Microbiology

20 Streptococci Anoverviewofdetection,identification,

differentiationandcultivationtechniques

New Product Corner

23 LC-MSSolventsforNormalPhaseChiralChromatography

23 NewEnvironmentalStandardsfromSigma-Aldrich

www.sigma-aldrich.com/analytix

Figure .........

Visitourupdated

HYDRANAL®websiteat

www.sigma-aldrich.com/

hydranal

Volumetric Reagents

Coulometric Reagents

WaterStandards Moisture

Testkit

Theory ofKarl Fischer

TitrationLiterature Technical

Helpline

Events / Links

HYDRANAL®

04

Impact of packaging materials on food safety and sensory qualityEstablishing,regulatingandmonitoringfoodsafetyareamong the most important applications of analyticalchemistry and chromatography. Food analysis coversmyriad subjects, including compositional analysis fornutritional labeling and monitoring adulteration,contaminationandcompliancewithregulations,amongothers. Foodstuffs can become contaminated from avariety of sources from the raw materials and at anypointalongtheproductionprocess,includingfromthepackagingmaterials.

Almost all foodstuffs consumed today are suppliedencasedinsomeformofpackaging.Byformingabarrierbetween the food and the environment, packagingmaterials maintain product quality and safety duringshippingandstorage.Packagingalsoprotectsthefoodfromotherpackagingmaterialsthatmayhavedesirablephysical properties but are notorious sources ofcontamination, likerecycledpaperboard[1].Thetypesofpackagingrangefromasimple,thincoatingoffood-grade wax to complex multi-layered systems thatcombine paper, plastic and metallic components withadhesives.

Howeverimportantthepackagingistomaintainingthefoodqualityandshelf-life,packagingmaterialsarealsoawell-knownsourceofcontaminationwhentheyleachundesirablecompoundsintothefoodtheyareintendedtoprotect. These compounds canbe toxins andposesignificanthealthhazards.Theycanalsobesourcesofoff-flavorsoroff-odors,diminishingthesensoryqualityof theproduct,which is a very important commercialaspectoffoodscience[2,3].

The etiology of the contamination reveals that themanufacturing process used to make the packagematerials, adhesives that hold multi-layer packagingtogether,andthevarnishes,inksanddyesappliedtothefinished package can all be sources of leachables orextractables thatendup in thefood.Solventsderivedfromthesesourcesareamajorcontaminationclassandareofprimaryconcerntofoodanalysts.

Current regulationsTo ensure consumer safety and customer satisfaction,the United States and the European Union haveimplementedregulationstoaddresstheuseofinksand

Residual Solvents from Food Packaging Materials ........ TwonewSupelcostandardscontaintwenty-fivesolventsofinterestforfoodsafetyandregulation

By Pat Myers, Senior R&D Chemist, Supelco … [email protected]

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dyes in foodpackagingandmeasure residual solvents[4,5]. TheUSFDA regulates residual solvents in foodpackaging as indirect food additives under 21 C.F.R.§175.300.Residualsolventsaresubjecttotheglobal50ppm migration limit that applies to non-volatile foodadditives as well. EU standards EN 13628-1 and EN13638-2setforthtestmethodsforthedeterminationofresidualsolventsinflexiblepackaging.ThesestandardsmonitorcompliancewiththeEUDirective89/109/EECthatappliestoallfood-contactsubstances.Thedirectivestates that food-contact substances must bemanufacturedinaccordancewithgoodmanufacturingpracticesandmustnotadulteratethefood.

Analytical challengeBesides establishing the barrier properties of new,innovative packaging with current food products andthe use of existing packaging materials for new foodproducts,foodmanufacturersandprocessorsmustalsoensuretheyareincompliancewiththeabove-mentionedregulations.Equallyimportantistheadoptionofanon-going in-house quality control program to monitorapprovedpackagingforunexpectedchangesinbarrierproperties that could result in undesirable levels ofresidualsolventcontamination.Monitoringforresidualsolventsfrompackagingmaterialsistypicallyperformedusingheadspace samplingwithGC/FIDorGC/MS [6].SPMEfollowedbyGCorGC/MShasalsobeenemployed[7].

One challenge faced by analysts testing for residualsolvents is the commercial availability of reliablereference standards. Without a commercial source,preparation of the standards is a time-consumingprocessinalreadyover-stretchedanalyticallaboratories.

Sigma-Aldrich solutionAnswering the need for reliable standards, Sigma-Aldrich developed two Supelco-brand residual solventstandardmixes.Thetwomixesrepresentthemajorityofsolvents found in the inks and dyes used for foodpackaging graphics and are not on the GenerallyRecognized as Safe (GRAS) listing (see Table 2). Allsolventsinthemixesarefirstscreenedforidentityandpurity. The mixtures are then gravimetrically preparedandquantitativelyanalyzedbyGC-MS(see Figure 1).ACertificateofAnalysisaccompanieseachstandard.

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Define your custom solvent and other ingredient mixturesEach packaging material has its unique palette ofpossible contaminants, and new packaging materialsarecontinuallybeingresearchedanddeveloped.Wearehappy to work with analysts in food and packagingindustriestodevelopcustomizedstandardsthatcontaincomponentsofspecificinterest.Toseeourcompletelistofstandardsanddiscussourcustomstandardservices,pleasecallorvisitournewly-designedWebsite:www.sigma-aldrich.com/standards

Table 2........ CompositionofSupelcoMixesforResidualSolventAnalysisinPackagingMaterials

Mix 1: 14 components (48994-U)

Mix 2: 11 components (48995-U)

1-Butanol 2-Ethoxyethylacetate

2-Butanol Isopropylacetate

2-Butanone Propylacetate

Butylacetate 2-Methoxyethanol

Cyclohexane 1-Methoxy-2-propanol

Cyclohexanone 4-Methyl-2-pentanone

Ethanol 2-Methyl-1-propanol

2-Ethoxyethanol Acetone

Ethylacetate 1-Propanol

Isobutylacetate 2-Propanol

Methanol Tetrahydrofuran

Methylacetate

2-Methoxyethylacetate

Toluene

References[1]Song,Y.S.;Begley,T.;Paquette,K.;Komolprasert,V.Effectiveness

of polypropylene film as a barrier to migration from recycledpaperboardpackagingtofattyandhigh-moisturefood.Food Additives and Contaminants 2003,20(9),875–883.

[2]Bravo,A.;Hotchkiss, J.H.;Acree,T.E. IdentificationofOdor-Active Compounds Resulting from Thermal Oxidation ofPolyethylene.J. Agric. Food Chem. 1992,40,1881–1885.

[3]Halek,G.W.;Levinson,J.J.PartitioningBehaviorandOff-FlavorThresholds inCookies fromPlasticPackagingFilmPrinting InkCompounds.J. Food Science1988,53(6),1806–1808.

[4]Keller and Heckman LLP. http://www.packaginglaw.com/index_mf.cfm?id=101(accessedMay3,2007).

[5]Preparation of Food Contact Notifications and Food AdditivePetitions for Food Contact Substances: ChemistryRecommendations, Final Guidance. http://www.cfsan.fda.gov/~dms/opa2pmnc.html(accessedMay3,2007).

[6]Detection of Packaging Emissions using a Flexible HeadspaceSamplerCombinedwithaMultiSensorSystemandaSeparationUnit.http://www.gerstel.com/p-gc-an-2005-07.pdf

(accessedMay3,2007).[7]Kusch,R.;Knupp,G.Headspace-SPME-GC-MSIdentificationof

Volatile Organic Compounds Released from ExpandedPolystyrene.J. Polymers and the Environment,2004,12(2),83–87.

Peak ID

1.2-Propanol

2.Acetone

3.1-Propanol

4.Isobutanol

5.Tetrahydrofuran

6.2-Methoxyethanol

7.IsopropylAcetate

8.1-Methoxy-2-Propanol

9.N-PropylAcetate

10.4-Methyl-2-Pentanone

11.2-EthoxyethylAcetate

0 10 20 30 40Time (min)

0 10 20 30 40

Time (min)

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5 6 7

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Figure 1 ......... GCAnalysisofResidualSolventMixesforPackagingStandards

GC Conditions: column: VOCOL, 60 m x 0.25 mm I.D., 1.5 µm df (24154); oven: 35 °C(4min.),4°C/min.to200°C(0min.); inj.:200°C;det.:MSD,280°C;carriergas:helium,30cm/sec.;ventflow:140mL/min.;injection:0.5µL

Peak ID

1.Methanol

2.Ethanol,Absolute

3.MethylAcetate

4.Sec-Butanol

5.2-Butanone

6.EthylAcetate

7.Cyclohexane

8.N-Butanol

9.2-Ethoxyethanol

10.IsobutylAcetate

11.Toluene

12.N-ButylAcetate

13.MethylCellosolveAcetate

14.Cyclohexanone

Table 1......... ProductListing

Residual Solvent Mixtures

Cat. No. Brand Description Package Size

48994-U Supelco Residual Solvents in Packaging Material Mix 1

14-componentmixturecontainingequalvolumes(eachcomponent7.14%v/v)ofthefollowing:

1-Butanol,2-Butanol,2-Butanone,Butylacetate,Cyclohexane,Cyclohexanone,Ethanol,2-Ethoxy-ethanol,Ethylacetate,Isobutylacetate,Methanol,Methylacetate,2-Methoxyethylacetate,Toluene

1mLampul

48995-U Supelco Residual Solvents in Packaging Material Mix 2

11-componentmixturecontainingequalvolumes(eachcomponent9.09%v/v)ofthefollowing:

2-Ethoxyethylacetate,Isopropylacetate,Propylacetate,2-Methoxyethanol,1-Methoxy-2-propanol,4-Methyl-2-pentanone,2-Methyl-1-propanol,Acetone,1-Propanol,2-Propanol,Tetrahydrofuran

1mLampul

Other analytical supplies

Cat. No. Brand Description

24154 Supelco VOCOLcapillaryGCcolumn,60mx0.25mmI.D.,1.5µmdf

06

TraceCERTTM – Traceable Certified Reference Materials. Part 4: Production, Handling and Storage of High-Precision Calibration Solutions ........ ThisisthefourtharticleofaseriesonCertifiedReferenceMaterialstoappearinAnalytix

InthelastissueofthisseriesonTraceCERTTMreferencematerials, we discussed the challenge of properlyselecting and characterizing high purity startingmaterials[1-3].Althoughthecompositionofthestartingmaterial iscriticaltoproducehighlyaccuratestandardsolutions, it canbeevenmore challenging toget thestartingmaterial intosolution.Neither lossofmaterialnor contamination with trace impurities is allowedduring the entire production process and duringshipmentandstorage.Thehigh-precisionsolutionmustarrive in the customer’s hand with all the qualitymeasures in terms of certified value, uncertainty andimpurity specifications fulfilled. Consequently, onlyhighly sophisticated equipment and well-definedproduction procedures make it possible to producecalibration solutionswithuncertaintiesof0.2%.Eventhebottlesandthepackagingareimportantwhenthesespecifications are to be guaranteed over years ofstorage. The equipment used for the production ofTraceCERTTM referencematerialswasdesignedby theSwiss Federal Institute for Materials Science andTechnology(EMPA).EMPAusedtheequipmentfortheproductionofsamplesfor interlaboratorycomparisonsat the highest metrological stage [4, 5]. When EMPAdiscontinued their metrological activities in 2005,Sigma-Aldrich Switzerland acquired this cutting-edgetechnologyaswellastheiruniqueknow-how.

Pretreatment of starting materialsWithfewexceptions(gold,palladium,etc.)thesurfaceofallmetallicstartingmaterialsarepre-cleanedbyacidetching(see Figure 1).Dilutedultrapurenitricacidorhydrochloric acid is used in most cases. The etched

By Michael Weber, Manager R&D Europe, Sigma-Aldrich Switzerland … [email protected]

and Jürg Wüthrich, Senior Scientist R&D Europe, Sigma-Aldrich Switzerland … [email protected]

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metal shots are transferred into high purity waterthrough washing with water several times andtransferred intoacetone.Finally, theshinymetalshotsare dried under argon. These procedures are allperformed in a clean room environment to avoidcontaminationwithdust.

Whensaltsareusedasastartingmaterial,theynormallyare dried in large, flat-bottomed borosilicate glass orVycordishesunderspecifieddryingconditions.Theairsupplytothehightemperatureovenisconnectedtoaclean room bench. The dried salt is then brought toroom temperature in a desiccator over anhydrousmagnesiumperchlorate.

High precision weighing: More challenging than you might expect!Itgoeswithoutsayingthathighprecisionbalancesareessential tools for accurate weight measurements.However,theenvironmentaroundthebalanceaswellasoperatortechniqueandknow-howarealsoofcriticalimportance(Figures 2, 3)[6].

Figure 1 ......... Etchingofhighpuritycoppershotasanexampleforstartingmaterialpretreatment

Figure 2 ......... Highprecisionbalancesona1,000kggraniteweighingtablewithstaticdischargeunitandclimatemonitoringinstrumentforairbuoyancycorrection

Figure 3 ......... Highprecision64kgbalancewith0.1greadabilityforbatchweighing

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specific for the material. This is important since thereactionbehaviorofmetalscandiffergreatlyfromonemetal to another. Some of the metals are passivatedimmediatelybysurfaceoxidationwhentheycomeintocontactwithconcentratednitricacidandthedissolutionreactionisstopped.Forexample,nickelcanbedissolvedovernight indilutednitricacidathigher temperatureswhileothermetals,suchasmagnesium,aremuchmorereactive and dissolution in concentrated acid leads touncontrolledandvigorousaerosolformation.Alossofstartingmaterialwouldbe thenegativeconsequence.Metalsshowingsuchadissolutionbehaviorarenormallydissolvedveryslowlyindiluteacidsfollowedbycoolingforseveralhours.Sincethealreadylowacidconcentrationdecreasesduringthedissolutionprocess,thereactionisdriven to completion by the addition of moreconcentratedacidtothestocksolutionattheendoftheprocess.Obviously,allthedissolutionreactionsaredonein totally inert bottles comprised of materials such asFEPorPFA.

Afterdissolution,theso-calledstocksolutioncontainingthe total amountofdissolvedanalyte isquantitativelytransferredintoa65LPVDFcontainer.Whilethemixingcontainerisstandingonthebalance,thebatchisfilledwithhighpuritywateruntilthecalculatedtotalmassofthefinalsolutionisreached.Thisgravimetricapproachallows a highly precise adjustment of the finalconcentrationofthecalibrationsolution.ThesolutionisthenhomogenizedbyoverheadtumblingofthePVDFcontainer for several hours (Figure 4). With thistechnique it can be assured that the solution has nomeasurable inhomogeneity; thiswasdemonstratedbyEMPA inan in-depth studywhen this equipmentwasusedforthepreparationofsamplesforinterlaboratorycomparisonsatthehighestmetrologicalstage[7].

Lastbutnotleast,thesolutionmustbeplacedintothefinal container bottles without any contaminationduring the transfer process. This is accomplished bybottling the standards under clean room conditionsusingPTFE-tubingandaninertperistalticpump.

For the gravimetric production of TraceCERTTMstandards, we built a special weighing room. Thebalancesstandonthree-pointsupportedgranitetablesweighingupto1000kg.Vibrationscannotaffect theweighingresultsandmaximumperformanceisthereforeobtainedfromthebalances.

Static electricity can be a source of weighing errors.Wheneverpossibleweusealuminumratherthanplasticvessels since the latter does suffer from problemsassociated with electrostatic discharge. Nevertheless,we still use a high voltage static charge dissipater tohelpensureaccurateweightmeasurement.Thisdeviceisespeciallyusefulwhenweighingdrysalts.

Ambientconditionsalsoaffectweighingaccuracy.Wecloselymonitor temperature,humidityandbarometricpressure in the weighing room since these data arenecessary to calculate the air buoyancy bias. Airbuoyancybiashas tobe taken intoaccount since thebalancesarecalibratedwithreferenceweightshavingadensity of 8000 kg/m3 while many starting materialshave higher or lower density. As a consequence, thedisplacement of air during calibration and sampleweighingisdifferent(calibrationweightsandsampledonotdisplace thesameamountofairbecause theydonot have the same volume per mass ratio). Theapproximately 1.2 kg/m3 density of air can affect theweighingresultupto0.1%.SincemanyTraceCERTTMstandardsarecertifiedwith0.2%totaluncertainty,theairbuoyancycorrectionisofcriticalimportance.

Ofcourse,alltheweighingdataaredirectlytraceabletothe SI unit kg by calibration the balances with SI-traceablecalibrationweights.OnlycalibrationweightsfulfillingOIMLclassE2andF1areusedtoensurehighestqualityoftheweightmeasurements.Besidesthenormalcalibrationweights (density8000kg/m3)wealsohavecalibration weights with a density of 2760 kg/m3(anticorrodal). This allows us to double-check the airbuoyancycorrection.

All of the high-precision balances used to produceTraceCERTTM standards are on regular maintenanceschedules,beingperiodicallycheckedandcalibratedbyathirdpartyandcertifiedaccordingtoDKDguidelines.Only by maintaining all of these stringent conditionsand continually improving our infrastructure can wecoverfullweightrangefrom1mgto65kgwithverylowuncertainties.

Dissolving, homogenization and bottlingEvery starting material is dissolved in high purity acid(mostlynitricorhydrochloricacid)followingprocedures

Figure 4 ......... The60LPVDFcontainersforoverheadtumblingofTraceCERTTMstandardsguaranteethecompletehomogenizationandensurethatnocontaminationfromcontainerwallintothesolutionandalsonoadsorptionofanalyteonthecontainerwallcanoccur.

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Storage and stabilityTheidealcontainerforstandardsolutionsistotallyinert,willnotadsorbanalyte,doesnot leach impurities intothe solution, is impermeable toward the solvent andatmosphere,andiseasytohandleandstore.Itislikelythat no container material will ever meet all of theserequirementsandstillbeaffordable.Wefoundthemostsuitable material available today was high-densitypolyethylene (HDPE) bottles in combination withaluminum-coatedbag typs,andchose them tobottleandpackageourTraceCERTTMUltrastandardsforICP.

HDPEbottlesfulfillthedemandfortheabsenceoftracecontaminants;mostelementscannotbedetectedevenatng/Lconcentrationlevelswhenthebottlesareleachedwith2%nitricacid.Someomnipresentcontaminations(e.g.calciumandsodiumions)mightbefoundatverylowµg/Llevels,whichisnottypicallyaproblemfor1g/Lstandards.IntheTraceCERTTMUltrastandards,upto70trace impurities are specified in the certificate. Thereportedvaluesfortraceimpuritiesincludecontributionsfromthestartingmaterial,thematrix(water,acidand/orbase)andfromleachingoutofthecontainer.

HDPE bottles are known to lose solvent throughtranspirationthroughthecontainerwall.Therateandextentoflossdependsontemperature,thicknessofthewall, its shape and surface. Solvent is depleted morerapidly when the surface-to-volume ratio is high.Consequently, attention should be paid to storageconditions when small bottles are used. To avoid theloss of solvent from the 100 mL TraceCERTTMUltrabottles, we weld them into aluminum-coated bags.Onlywiththispackagingtechniquecanweguaranteetheambitiousspecificationof0.2%uncertaintyforthecertifiedvalueovertheentireshelflifeofthestandard.Thesolventtranspirationrateof100mLHDPEbottleswith and without the aluminum-coated bag at 23°Cand30°Chasbeeninvestigatedcomprehensivelyduring

References[1]TraceCERT™–TraceableCertifiedReferenceMaterials.Part1:

Swiss precisionmeets analytical competence.Analytix, Vol. 5,2006.

[2]TraceCERT™–TraceableCertifiedReferenceMaterials.Part2:Whatuncertaintyreallymeans.Analytix,Vol.1,2007.

[3]TraceCERT™–TraceableCertifiedReferenceMaterials.Part3:Challenges in the characterization of high-purity startingmaterials.Analytix,Vol.2,2007.

[4] FelberH.;Weber,M.FinalreportonkeycomparisonCCQM-K8ofmonoelemental calibration solutions.Metrologia2002, 39,Tech.Suppl.,08002.

[5] Weber M., Wüthrich J., Key comparison CCQM-K29: Anioncalibration solutions: final report. Metrologia 2006, 43, Tech.Suppl.,08012.

[6]Reichmuth A., Wunderli S., Weber M., Meyer V.R., Theuncertaintyofweighingdataobtainedwithelectronicanalyticalbalances,MicrochimicaActa2004,148(3-4),133-141.

[7]Weber M., Wüthrich J., High Precision Titrimetry, IonChromatographyandICP-OpticalEmissionSpectrometryfortheEstimationofInhomogeneitiesinAqueousCalibrationSolutionsforMetrologicalPurposes, 2004,146(2),165-171

Figure 6 ......... PackagingofTraceCERTTMUltrastandardsforICPtoensure±0.2%expandeduncertaintyforthecertifiedvalue.OnlywhenusingspeciallyselectedAl-coatedbagsthespecificationsoftheCRMcanbeguaranteedtohaveashelflifeofupto4years

Many aspects of preparing high-quality referencematerialsthatseemsimpleorirrelevantturnouttobeofcrucialimportance.Wehopethat,throughthisseriesoffourarticles,wehaveshownhowimportantitistochoose the right CRM supplier, one whose expertiseandequipmentareequaltothechallengeofhandlingof sensitive raw materials and producing high puritystandards suitable for today’s sensitive analyticalmethods.CRMproductionreallyisaspecialtaskwithinthe world of chemical reagents and standards. AtSigma-Aldrich, we are committed to meeting andexceedingyourexpectationsasaqualityCRMprovider.

ToviewtheTraceCERTTMline,pleasevisitourwebsite:www.sigma-aldrich.com/tracecert

Figure 5 ......... Transpirationbehaviorofanaqueouscalibrationsolutionina100mLHDPEbottleatdifferenttemperatures

1.000

1.002

1.004

1.006

1.008

1.010

0 1 2 3Years

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measured (mean of 9 bottles)extrapolated

Bottle storedwithout Al-bag

Bottle storedin Al-bag

23°C

30°C

30°C

23°C

Transpiration through HD-PE bottles

anEMPAstudy(Figure 5).

Duringthepreparationofthisarticle,werealizedthattherearemanymore issuesonwhichwecouldwrite.

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Determination of the Hydrocarbon Oil Index in Soil, Water and Sludge ........ Kitsandtestsetsforthechromatographicdeterminationofhydrocarboncontent

Forthedeterminationofmineraloilcontentinvariousmatrixes (water, soil, sludge) three different DIN/ENstandards exist. Each one specifies a method for thedeterminationofthehydrocarbonoilindexbymeansofextraction in n-heptane followed by analysis by gaschromatography(GC).

The hydrocarbon oil index is the sum of the concen-trationsoflong-chainandbranchedaliphatic,alicyclic,aromatic and alkyl-substituted aromatic hydrocarbonspresent in the sample that are extractable with ahydrocarbonsolventwithboilingpointabove36°C,arenot adsorbedon Florisil andhaveGC retention timesbetweenn-decane(C10)andn-tetracontane(C40).

Sigma-Aldrich offers two Mineral Oil kits and threeFlorisil®suitabilitytestsetsthatcontainspecialduallayerFlorisil®/Na2SO4SPEtubesandallreagentsandstandardsusedintheabove-mentionedISO/DIN/ENstandards.

The kits allow users to extract and analyze fifteenwatersamplesinduplicate(kit68172),twenty-twosoilsamples (kit 56681), twenty solid waste samples oreightliquidwastesamples(kit56681).

TheFlorisil®suitabilitytestsetsweredevelopedfortheanalysis of ten (set 52462), nineteen (set 09758) ortwenty-fourFlorisil®(set50397)samples.

ThespecialmineraloilstandardmixturetypeAandB,which is used as a stock solution for calibration, isproduced gravimetrically from the certified referencematerialBAM-K010suppliedbytheFederalInstituteforMaterialsResearchandTestingBAM.Theexactcontent,includingtheexpandeduncertaintyandtheexpirydate,appearsonthelabel.Thiscertifiedstandardsolutionissupplied in CERTAN® capillary bottles which ensure aperfect seal and guarantee a constant analyteconcentration.

By Ingrid Hayenga, Senior Scientist, R&D Europe … [email protected]

Method Matrix Title Scope

DINENISO9377-2:2000

Water WaterQuality–Determinationofhydrocarbonoilindex

Limit:hydrocarbonoilindex>0.1mg/L

ISO16703 Soil Soilquality–DeterminationofcontentofhydrocarbonintherangeC10toC40bygaschromatography

Scope:between100mg/kgand10,000mg/kgmineraloilcontentinsoil,expressedasdrymatter

EN14039 Sludge Characterizationofwaste–DeterminationofhydrocarboncontentintherangeofC10–C40bygaschromatography

Scope:hydrocarboncontent>100mg/kginwaste,expressedasdrymatter

Table ......... Testkitsandsuitabilitytestsets


68172 Fluka KitforthechromatographicdeterminationofhydrocarboncontentinwateraccordingtoENISO9377-2

56681 Fluka Kitforthechromatographicdeterminationofhydrocarbon content in soil accordingtoDINISO16703andinwasteaccordingtoEN14039

07958 Fluka Florisil®suitabilitytestaccordingtoDINEN14039

52462 Fluka Florisil®suitabilitytestaccordingtoENISO9377-2

Florisil®isaregisteredtrademarkoftheU.S.SilicaCompanyCERTAN®isaregisteredtrademarkofLGCPromochem

10St

and

ard

s


HPLC/MS-MS for the Quantitative Multi-Target Analysis of Mycotoxins ........ TrichotheceneandothermycotoxinstandardsfromSigma-Aldrichenablereliablequantitation

Michael Sulyok, Department of Agrobiotechnology (IFA-Tullin),

University of Natural Resources and Applied Life Sciences, Vienna, Austria… [email protected]

Toxicmetabolitesproducedbymiscellaneousgeneraoffungigrowingonplantsincludeavarietyofstructurallydifferent compounds. This diversity has lead to thedevelopmentofmanyanalyticalmethodsdealingwithsingle classes of mycotoxins that include a limitednumberoftargetanalytes.Synergisticeffectshavebeenobserved concerning the toxicity of mycotoxins andhave initiated the search for methods for thesimultaneousscreeningofdifferentclassesoftoxins.

However, the development of a single HPLC-basedmethodisadifficulttasksincethelistofrelevanttoxins

Table 1 .......... TrichotheceneandotherMycotoxinStandardsfromSigma-Aldrich

Allsolutionsinacetonitrileexceptasnoted.

Cat. No. Brand Description Concentration Package Size

34124 Riedel-deHaën,OEKANAL® Deoxynivalenolsolution 100µg/mL 2mL

34128 Riedel-deHaën,OEKANAL® Deoxynivalenol-13C15solution 25µg/mL 1mL

34129 Riedel-deHaën,OEKANAL® 3-Acetyl-d3-deoxynivalenolsolution 100µg/mL 2mL

34130 Riedel-deHaën,OEKANAL® FusarenonXsolution 100µg/mL 2mL

34131 Riedel-deHaën,OEKANAL® Nivalenolsolution 100µg/mL 2mL

34132 Riedel-deHaën,OEKANAL® 3-Acetyldeoxynivalenolsolution 100µg/mL 2mL

34133 Riedel-deHaën,OEKANAL® 15-Acetyldeoxynivalenolsolution 100µg/mL 2mL

34134 Riedel-deHaën,OEKANAL® B-Trichothecenemix,(DON,NIV,3-AcDON,15-AcDON)

100µg/mL 2mL

34135 Riedel-deHaën,OEKANAL® Deepoxy-deoxynivalenolsolution 50µg/mL 2mL

34138 Riedel-deHaën,OEKANAL® Neosolaniolsolution 100µg/mL 2mL

34139 Riedel-deHaën,OEKANAL® FumonisinB1solution 50µg/mL 2mL

34142 Riedel-deHaën,OEKANAL® FumonisinB2solution 50µg/mL 2mL

34143 Riedel-deHaën,OEKANAL® FumonisinMixture 50µg/mLinacetonitrile:water 2mL

34155 Riedel-deHaën,OEKANAL® Deoxynivalenol-d1solution 100µg/mL 2mL

34029 Riedel-deHaën,OEKANAL® AflatoxinB1solution 2µg/mL 2mL,5mL

34031 Riedel-deHaën,OEKANAL® AflatoxinM1solution 0.5µg/mL 2mL,5mL

34032 Riedel-deHaën,OEKANAL® AflatoxinG1solution 2µg/mL 2mL,5mL

34033 Riedel-deHaën,OEKANAL® AflatoxinG2solution 0.5µg/mL 2mL,5mL

34034 Riedel-deHaën,OEKANAL® AflatoxinB2solution 0.5µg/mL 2mL,5mL

34036 Riedel-deHaën,OEKANAL® AflatoxinMix4solutionB1G1B2G2

2µg/mL(B1andG1)0.5µg/mL(B2andG2)

2mL,5mL

33415 Riedel-deHaën,OEKANAL® AflatoxinMix4solutionB1G1B2G2

20µg/mLeach 2mL

34037 Riedel-deHaën,OEKANAL® OchratoxinAsolution 10µg/mL 2mL,5mL

34126 Riedel-deHaën,OEKANAL® Zearalenonesolution 100µg/mL 2mL

34127 Riedel-deHaën,OEKANAL® Patulinsolution 100µg/mL 2mL

11

Stan

dar

ds

Figure 1 ......... HPLC-ESI-MRMchromatogramofamulti-analytestandardinthepositive

ionizationmode.Analytesinorderofelutionareagroclavine(1;LOD:0.02µg/L),

neosolaniol(2;0.5),verrucarol(3;21),ergovaline(4;0.08),monoacetoxyscirpenol(5;

0.5),dihydroergosine(6;0.2),ergotamine(7;0.06),diacetoxyscirpenol(8;0.5),hydrolysed

fumonisinB1(9;0.3),ergocornine(10;0.25),fumonisinB1(11;2),HT-2toxin(12;4),

T-2toxin(13;0.25),verrucarinA(14;2),ochratoxinB(15;0.25),fumonisinB2(16;1),

ochratoxinA(17;0.5),enniatinB(18;0.004),enniatinB1(19;0.015),beauvericin(20;0.01),

enniatinA1(21;0.015)andenniatinA(22;0.002).ThepeaksofaflatoxinG2(11.05min;

0.25),aflatoxinG1(11.39min;0.13),aflatoxinB2(11.76min;0.25)andaflatoxinB1(12.07

min;0.5)arenotvisible.

includes small quasi-ionic molecules (moniliforminexhibitsapKavalueof1.7)andapolarsubstances(suchastheenniatins)aswellasacidicandalkalineanalytes(fumonisins and ergot alkaloids, respectively). As aconsequence,theconditionsduringsamplepreparationandchromatographicseparationareacompromiseandmaybefarfromoptimalforcertaintargetsubstances.Ideally, the sample preparation procedure should bereduced to a single extraction step, since it can beexpectedthatanyattempttouseacleanupwouldresultinsignificantlossesofcertainanalytes.

Sinceageneral,selectiveandrobustdetectionmethodcapable of confirming the molecular identity of thetargetanalytesincomplexmatrixesisrequiredformulti-target methods, HPLC-MS/MS is the technique ofchoice. However, this technique is considered to beinadequateforquantitativeanalysisofrawextracts,asco-elutingmatrixcomponentsoftenreduceorenhancetheionizationefficiencyoftheanalyte.Thisnegativelyaffectstherepeatabilityandtheaccuracyofthemethodand, in extreme cases, the signal may be completelysuppressed.

Recently,weshowedthatthelatestgenerationofmassspectrometers tolerates the direct injection of crudeextracts[1].Thisallowedthedevelopmentofamethodfor the quantitative determination of 39 mycotoxinsbased on HPLC-ESI-MS/MS in the so-called multiplereaction monitoring mode (see Figures 1 and 2).Excellent linearities and repeatabilities were obtainedfortheanalysisofwheatandmaizesamplesspikedatmultiple concentration levels. Therefore, it wasconcluded that matrix induced-signal suppression canbe compensated by using matrix-matched calibration,i.e.blankmatrixsampleextractsfortifiedwithasuitableamountofastandardsolutioncontainingtheanalytesof interest. For deoxynivalenol and zearalenone, thetrueness of the method was confirmed by analyzingcertified reference materials. Generally speaking, theshortageofstandardsmaybeconsideredtobethemainobstacleinmulti-mycotoxinanalysis,asreliablereferencesubstancesandmaterialsareavailableonlyforasmallfraction of the 300-400 substances that are currentlyrecognizedasmycotoxins.

Sigma-Aldrich, through its Riedel-de Haën OEKANALbrand,ispleasedtooffermanytrichotheceneandothermycotoxinstandardsasneatsolutionsandmixtures(seeTable 1).

Reference[1] Sulyok, M.; Berthiller, F.; Krska, R.; Schuhmacher, R. Rapid

Commun. Mass Spectrom.2006,20,2649–2659.


Figure 2 ......... HPLC-ESI(-)-MRMchromatogramofamulti-analytestandardinthenegative

ionizationmode.Analytesinorderofelutionaremoniliformin(1;LOD:2.5µg/L),nivalenol

(2;2.5),patulin(3;10),deoxynivalenol(4;2),deoxynivalenol-3-glucoside(5;0.5),fusarenon-

X(6;2),deepoxy-deoxynivalenol(7;2),3-acetyldeoxynivalenol(8;1.5),zearalenone-4-

glucoside(9;0.25),ochratoxinalpha(10;4.5),beta-zearalenol(11;0.13),zearalenon-4-

sulfate(12;0.004),alpha-zearalenol(13;0.13)andzearalenone(14;0.007).

Inten

sity, cps

4.0e5

2.0e5

1

2+3

4+5

8

9

6

107

13

11

14

12

3 4 5 6 87 Time, min 11 12 13 14 15

Inten

sity, cps

1.5e6

5.0e5

1

23

4

5

7

8

910

11+12

13+14+15

16 17

22

21

18

19+20

9 10 11 12 Time, min 14 15 16

6

12C

hro

mat

og

rap

hy

www.sigma-aldrich.com/ic

High-Purity Water for Ion Chromatography from Sigma-Aldrich ........ Flukaexpertise,dedicatedproduction,detailedtestingandspecialpackagingguaranteehighestqualityforsensitiveanalyses

Water is an omnipresent variable in many chemicalanalyses,whetheritisusedasareagent,eluentmobilephase, cleaning agent, sample solvent or referencematerial. Its composition must be well-characterizedand controlled in order to obtain sensitive, precise,accurateanderror-freeresultsandmaintaininstrumentperformance. To maintain the purity from the high-qualityproduction,storagecontainersmustbechosenthatdonotleachcontaminantsandareimpermeabletoatmosphericgases.

Ionchromatography(IC)isanareawherethequalityofthewaterisespeciallyimportantbecauseitisusedasaneluentforppm-toppb-andsometimesevenppt-leveldeterminations of anions and cations. Researchers atSigma-Aldrich‘s Fluka brand have developed a qualitygradeofwaterspecificallyforsensitiveICapplications.This IC-grade water is suitable for trace analysis ofanions,cationsandalsosomeorganicsthataretypicallyanalyzedbyIC.Toensurelong-termquality,itissuppliedinspecialstoragecontainersthathavebeenproveninextendedstoragetests(Figure 1).

The importanceofwater quality is testified toby thenational and international norms that have beendeveloped for the specification of purified water for

different applications. ISO 3696:1987, for example,specifies three different types of water. Type 1 is thehighest analytical grade for high-purity analysis likeHPLCorICtraceanalysisandislargelyfreeofdissolvedimpurities (inorganic, organic), colloidal impurities,specifiedforconductivity,UVabsorptionat254nmandSiO2content.ASTMD1193-91alsospecifieshigh-puritywaterbutalsousesTOC,resistance,sodiumandchloritelevels to measure quality. Also, trace analysis by ICaccording to ASTM D5542-94, for example, requireshigh-puritywaterduetothelowdetectionlevels.Atthevery minimum, type 1 water is necessary to providesatisfactory results for trace analysis, as today‘sinstrumentsaresensitivetoevenppt-levelsofanalytesandcontaminants.

Sigma-Aldrichhaslongsuppliedabroadrangeofhighquality water products tailored around the specificneedsofthemyriadanalyticalchemistryapplicationswesupport.Inkeepingwiththistradition,wenowofferanIC-gradeofwaterproducedatourBuchsfacilityusingvarious purifying stages and highly sensitive online-analyses.Theproductpackaginghasbeendesignedtoensurethequalityofthewaterwillbemaintainedwhenitisputtousebytheconsumer.

Specifications for Fluka brand IC-Grade Water from Sigma-AldrichAnionTracesBromide, chloride, fluoride, iodide, nitrate, nitrite,phosphate,sulfate:≤1µg/kgeach

CationTracesAl,Ba,Bi,Cd,Co,Cr,Cu,Fe,Li,Mg,Mn,Mo,Ni,Pb,Sr,Zn:≤5µg/kgeach;Ca,K,Na:≤10µg/kgeach;NH4

+:≤50µg/kg

OrganicTracesAcetate,formate,glycolate,oxalate:≤10µg/kgeach

Conductivity≤2µS/cm

By Nicole Amann, Product Manager Analytical Standards, Sigma-Aldrich … [email protected]

Table......... IC-GradeWater

Cat. No. Brand Description Package Size*

00612 Fluka WaterforIonChromatography

2.5Land5L

Packaging:HDPEbottleswith45mmthread

Figure 1 ......... Anionchromatogramfroma4monthsleachingtestofthe2.5LHDPEbottle.

Theblacklineshowstheanionsandorganicsintheconcentrationofthespecificationlimits.The

peaks are: (1) fluoride, (5) chloride, (7) nitrite, (8) bromide, (9) nitrate, (10) phosphate, (11)

sulfate,(13)iodidewith1µg/kgeach(2)formiate,(3)glycolate,(4)formiateand(13)oxalate

with10µg/kgeach(6)systempeakfromcarbonateeluent

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75mV

4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 min

1

3

2

4

5

6

7

89

10

11

12

13

r2201527r2221327

13

Ch

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www.sigma-aldrich.com/ic

Certified Eluent Concentrates for Ion Chromatography from Sigma-Aldrich ........ Well-characterizedsolutionsofcommoneluentsareaconvenienttime-andcost-savingoptionandcomplementourlineofICstandards

Ionchromatography(IC)isananalyticaltechniquethatisusedtoseparateandquantifyppm-levelsofcommonanions(e.g.fluoride,chloride,nitrite,nitrateandsulfate)and cations (e.g. lithium, sodium, ammonium andpotassium) in aqueous samples. It is also applied toanalysisoforganicionssuchasorganicacids,hydrazineand methylated hydrazines. Separation occurs viadifferential interaction with an ion-exchange resin.Conductivity is the typical detection method. Thesensitivity of IC makes it ideal for low-ppm levelquantification, andalso for traceanalysis, it thereforecreates the requirement for high purity eluents andwell-defined standards. As a leading supplier of highquality products for all areas of analytical chemistry,Sigma-AldrichhasexpertiseinproductionofstandardsandeluentssuitableforsensitiveICdeterminations.Eluents (mobile phases) for IC typically are dilutesolutionsofacids,basesorsalts.WhenpreparinganICeluent, to ensure reliable and accurate low-levelquantification, close attention must be paid to thequality of the starting materials, purity of the water,preparation technique, storage vessel and storageconditions. Concentrationof theeluentshouldbeasconstant as possible in order to achieve highlyreproducibleresults.

DesignedtosaveanICanalysttimeandensurethemostsensitiveandreproducibleICdeterminations,ourlineofpre-made Certified Eluent Concentrates for IC is aconvenient time- and cost-saving option. Thesesolutions, listed in the Table, are traceable bypotentiometric titration to NIST Standard ReferenceMaterialsandcertifiedinaccordancewithISOGuide31.All details regarding exact content, uncertainty,traceability and expiry date are described in theCertificate of Analysis which is available electronicallyon our web page (http://www.sigma-aldrich.com).TheFigureisanexampleofaCertificateofAnalysisforour0.1Mmethanesulfonicacidsolution.To complete your IC analysis, we also offer acomprehensive line of IC calibration standards thatcomprisessingleionstandards,multi-ionstandardsandmulti-ionCertifiedReferenceMaterials(PRIMUS).

By Nicole Amann, Product Manager Analytical Standards, Sigma-Aldrich … [email protected]

Table ......... CertifiedEluentConcentratesforICfromSigma-Aldrich

Cat. No. Brand Description Package Size*

50439 Fluka PerchloricAcidSolutionforIC,0.01Minwater

1L

36486 Fluka SodiumBicarbonateSolutionforIC,0.1Minwater

1L

56169 Fluka SodiumCarbonateSolutionforIC,0.1Minwater

1L

43617 Fluka SodiumHydroxideSolutionforIC,0.1Minwater

1L

50972 Fluka 2,6-PyridinedicarboxylicAcidSolutionforIC,0.02Minwater

1L

68487 Fluka OxalicAcidSolutionforIC,0.1Minwater 1L

16355 Fluka NitricAcidSolutionforIC,0.1Minwater 1L

68279 Fluka SulfuricAcidSolutionforIC,0.1Minwater 1L

50433 Fluka DL-TartaricAcidSolutionforIC,0.1Minwater 1L

61699 Fluka PotassiumHydroxideSolutionforIC,0.1Minwater

1L

55517 Fluka MethanesulfonicAcidSolutionforIC,0.1Minwater

1L

*Packaging:1LHDPEbottleswith45mmscrewthread

Figure ......... ExampleofCertificateofAnalysisfor

MethanesulfonicAcidSolution(55517-1L)

This certificate is designed in accordance with ISO Guide 31 [1]

Object of certification: Methanesulfonic acid solution 0.1 mol/L in waterFluka Product No.: 55517 (Lot 44706A01)

Composition: Methanesulfonic acid (purum, >98%, Fluka Prod. No. 64285) dissolved in Ar-degased high purity water (18.2 M .cm, 0.2 µm filtered)

Certified value traceable to NIST and BAM certified reference materials and uncertainty according to ISO Guide 35 [2] and Eurachem/CITAC Guide [3]

Constituent Certified value at 20°C Combined expanded uncertainty [U = k.uc; k = 2]

Methanesulfonic acid 100.0 mmol/L 0.4 mmol/L

Intended use: Concentrate for preparation of eluents for ion chromatography

Storing and handling: This eluent concentrate solution shall be stored between 5°C and 30°C. In order to avoid evaporation the bottle should be tightly closed prior to use.

Expiry date: 28. October 2008 (unopened bottle)

Traceability statement: This eluent concentrate solution is traceable by potentiometric titration to NIST SRM 723c and also traceable to BAM certified titrimetric reference material (Fluka Prod. No. 93440).

Uncertainty calculation: All uncertainties are calculated according to Eurachem/CITAC Guide [3] and reported as combined expanded uncertainties at the 95% confidence level. Contributions from reference material, potentiometric titration measurements and storing effects are included in the reported uncertainty budget.

Reviewing Chemist Certification body Date of release Quality System

K.-D. Schmidt, Ph.D. J. Wüthrich November 27th 2006 SQS Reg. No. 16368-02

[1] ISO Guide 31, 1-7, 1st Ed. (1981), “Contents of certificates of reference materials” [2] ISO Guide 35, 1-7, (2000), “Certification of reference materials – general and statistical principles”[3] Eurachem/CITAC Guide, 1-120, 2nd Ed. (2000), “Quantifying uncertainty in analytical measurement”

Certificate page 1 of 1 Fluka is a brand of

Eluent Concentratefor Ion Chromatography

14Sp

ectr

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www.sigma-aldrich.com/spectroscopy

Figure 2 ......... ReactionofFe2+with1,10-phenanthroline

Spectroscopic Reagents for UV/VIS by Sigma-Aldrich ........ Awiderangeofhigh-qualityreagentsforsensitive,quantitativedeterminations

UV/VIS spectroscopy is routinely used for quantitativedeterminationoftheconcentrationoftransitionmetalions and highly conjugated organic compounds insolution.Sigma-Aldrichoffersawiderangeofchemicalsfor the quantitative photometric analysis of ions andother molecules by UV/VIS spectroscopy. In order toguaranteesuitabilityforthisapplication,ourhighqualityreagents havehomogeneous appearance andpossessnoextraneouscolor.

TheoryManymoleculesabsorblightintheultraviolet(10-380nm)orvisible (380-780nm)range.Theenergyoftheabsorbed light in these ranges stimulates transitionsbetweenelectronicstateswithinthemolecule(Fig. 1).

By Michael Jeitziner, Market Segment Manager Analytical Reagents & Standards … [email protected]

Figure 1 ......... Theelectromagneticspectrum

1024 1022 1020 1018 1016 1014 1012 1010 108 106 104 102 100

10810610410210010-210-410-610-810-1010-1210-1410-16

v(Hz)

λ(m)

y rays X rays UV IR Microwave FM AM

Radio waves

Long radio waves

Increasing frequency (v)

Increasing Wavelength (λ)

Visible spectrum

Increasing Wavelength (λ) in nm

400 500 600 700

FeNN

3

Fe2+

NN

3

2+

+

Fe(II) 1,10-phenanthroline Fe(II)-1,10-phenanthrolineanalyte complex

Beer’s Law:

A=e·c·l

Allowsdeterminationofconcentration(c)

oftheanalyteinmol/Lbasedon:

A=absorbance(lightabsorption)ofthe

material(cm)

e=molarabsorptivity(molarextinction

coefficient)(L·mol-1·cm-1)

l=pathlength(cm)

form of absorption spectroscopy, the intensity ofabsorption and its concentration are linearly relatedaccording Beer’s Law (see box inset above). Manyhundreds of such specific complexation reagents areavailableforalltypesofanalytesandsamplematrixes.

Forquantitativeanalysis,thewavelength(l)ofmaximumabsorbance of the complex is chosen (Fig. 3). In thisexample, a wavelength of 508 nm was chosen. Ifliterature values are not available, molar absorptivity(extinction coefficient) can be determined by dividingtheslopeofthecalibrationcurveofAvs.concentrationbythepath length (withproperunitconversion). Inter-polationofthecalibrationcurveisalsousedtodeterminetheconcentrationofunknownsolutions(Fig. 4).

Quantitative analysis of metal ionsTocompensateforanalytesthatdonotabsorbstrongly,they are commonly derivatized to form a stronglyabsorbing product. An example of this is shown inFigure 2.Thecolorlessanalyte,Fe2+,isreactedwiththe1,10-phenanthroline derivatization reagent to form acolored complex that absorbs strongly in the visibleregion of the electromagnetic spectrum. As with any

www.sigma-aldrich.com/spectroscopy

15

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Figure 3 ......... AbsorptionspectraofFe(II)-1,10-phenanthrolinecomplex Figure 4 ......... StandardcalibrationcurveofFe(II)followingderivatizationwith1,10-phenanthroline

Table ......... ReagentsforUV/VISSpectroscopyfromSigma-Aldrich

Cat. No. Brand Description Analyte CAS No. Package Size

08751 Fluka 4-Amino-3-hydroxy-1-naphthalenesulfonicacid Si 116-63-2 25g,100g

11635 Fluka Azomethine-Hmonosodiumsalthydrate B 206752-32-1 5g,25g

11870 Fluka Bathocuproinedisulfonicaciddisodiumsalt Cu,Fe 52698-84-7 250mg,1g

11880 Fluka Bathophenanthroline Fe 1662-01-7 500mg,1g,5g

15100 Fluka BismuthiolI Bi,Cu,Pb,Sb 1072-71-5 10g

31550 Fluka 2,3-Butanedionemonoxime Co,Ni,Pd,Re 57-71-6 25g,100g,500g

32750 Fluka 3,3‘-Diaminobenzidinetetrahydrochloridehydrate Se,Te 868272-85-9 1g,5g,25g

38520 Fluka 2,3-Dimercapto-1-propanol Cu 59-52-9 5mL,25mL

40390 Fluka Dimethylglyoxime Co,Fe,Ni,Pd,Re 95-45-4 25g,100g,500g

72530 Fluka Nioxime Fe,Ni 492-99-9 5g

77500 Fluka 1,10-Phenanthrolinemonohydrate Fe,Pd,V 5144-89-8 5g,25g,100g

85180 Fluka Silverdiethyldithiocarbamate As 1470-61-7 10g,50g

87748 Fluka 3,3‘,5,5‘-Tetramethylbenzidine Cl2 54827-17-7 1g,5g,25g

89630 Fluka p-Toluidine Au,Tl 106-49-0 25g,100g,500g

89700 Fluka Toluene-3,4-dithiol(Dithiol) Ag,Mo,Re,Sn,W 496-74-2 1g,5g

OurcompletelistofreagentsforspectroscopycanbefoundatourWebsite(seebelow):

Concentration (mg/L) Fe(II)Wavelength (nm)

1 2 3 4

2+

0.4

0.8

1.21.00

0.90

0.80

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.0

3.50

4.00

4.50

5.00

5.50

6.00

6.50

7.00

= 508 nm

A A

16Se

nso

rics

Selectophore® Products ........ Sigma-AldrichintroducestwonewionsensorsforpH(H+)andHg2+determination

ApHelectrode isbasicallynothingmorethanan ion-selective electrode (ISE) for hydrogen ions. Glass pHelectrodesarethemostwell-known,butpHelectrodesbased on polymer membranes are viable alternatives.Polymer membranes are disposable, flexible, easy toprepareandhaverapidresponsetimes.Thesequalitiesmakemembraneelectrodesideallysuitedforfoodandbeverageapplications,sincetheyeliminatedthehazardofbrokenglasscontaminatingtheproduct.

8 Ionophore for pH MeasurementETHT2418,Octadecyl2-(4-dipropylaminophenylazo)-benzoate,Selectophore®‚≤99.0%(HPLC)(Fluka17384)

Thisionophorecanbeusedforbothpotentiometric[1,2,3]andopticalpHmeasurement[4].ThehighselectivityevenpermitspHmeasurementsatnormalphysiologicalintracellularpHaswellasinacidicphysiologicalmedia[1].

By Michael Jeitziner, Market Segment Manager Analytical Reagents & Standards … [email protected]

S

HN

S

O

S

N

O

O

NCH33H C

NN

O OCH 2(CH 2) 16CH3

CH

H3C

3Figure 1 ......... ETHT2418

H,M

Characteristics

Slope(sensitivity):57.5±0.5mV/dec(pH<1-9)

Electricalresistance,tipdiameter~1µm:~35±8(n=7)GW

Responsetime:<3s

SelectivityCoefficientslogKPotasobtainedbythefixed

interferencemethod(FIM):

logKPot-8.6,logKPot-9.7,logKPot<-7.8

Membranecompositionacc.tolit.[3]:

10.0 wt% Octadecyl2-(4-dipropylaminophenylazo)-

benzoate(17384)

33.5 wt% 2-Nitrophenyloctylether(o-NPOE)(73732)

1.0 wt% Potassiumtetrakis(4-chlorophenyl)borate

(60591)

15.9 wt% Poly(vinylchloride)highmolecularweight

(81392)

17.1 wt% Chloroparaffin(25720)

22.5 wt% Mesamoll®(50987)

H,Na H,K H,Ca

Table ......... ProductTable:H+ISE


17384 Fluka ETHT2418,Octadecyl2-(4-dipropylamino-phenylazo)benzoate

50mg,250mg

60591 Fluka Potassiumtetrakis(4-chlorophenyl)borate 100mg,1g,5g

73732 Fluka 2-Nitrophenyloctylether(NPOE) 5mL,25mL,100mL

81392 Fluka Poly(vinylchloride)highmolecularweight 1g,10g,50g

25720 Fluka Chloroparaffin 5mL

87369 Fluka Tetrahydrofuran 10mL,100mL,500mL

References[1] Spichiger,U.;Aiping,X.;Citterio,D.;Bühler,H.;Chaniotakis,N.;

Rusterholz,B.;Simon,W.;Electroanalysis 1995,7,859-863.[2] Bakker,E.;Nägele,M.;Schaller,U.;Pretsch,E.;Electroanalysis

1995,7,817-821.[3] Zhang, X.; Fakler, A.; Spichiger, U.; Anal. Chim. Acta 2001,

445,57-65.[4] Zwickl,T.;Schneider,B.;Lindner,E.;Sokalski,T.;Schaller,U.;

Pretsch;Anal. Chim. Acta1998,14,57-61.[5] Shamsipur,M.;Hosseini,M.;Alizadeh,K.;Alizadeh,N;Yari,A.;

Caltagirone,C.;Lippolis,V.:Anal. Chim. Acta2005,533,17-24.

Superior pH electrodes from Sigma-AldrichThese high quality pH combination electrodes willprovideexcellentperformanceatapricethatofferssuperiorvalue.

LaboratorypHelectrode(pHcombinationelectrode)preciseandreliablepHmeasurement

pHStick-inelectrode(pHcombinationelectrode)for stick-in measurements of meat, cheese, breadandothersemisolidfood

UniversalpHelectrodeforonlinemeasurements(pHcombinationelectrode)veryrobustpHelectrode,especiallyusedforonlinemeasurementsinwastewater,galvanic,etc.

www.sigma-aldrich.com/sensoric

17

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Table ......... Technicalspecifications

Description Laboratory pH electrode pH Stick-in electrode Universal pH electrode for online measurements

Productnumber 53162-1EA-F 30948-1EA-F 57458-1EA-F

Measuringrange 0…14pH 0…14pH 0…14pH

Operatingrange 0…100°C(32…212°F) 0…60°C(32…140°F) 0…120°C(32…212°F)atmax.6bar

Referenceelectrolyte refillable,KClc=3mol/L,Ag+-free polymergel,blue-dyed polymergel

Referencesystem Ag/AgClcartridge Ag/AgCl Ag/AgClcartridge

Internalbuffer pH=7.0±0.25 solid,pH=7.0±0.25,blue-dyedforfindingglasssplintersafterbreakageofglass

pH=7.0±0.25

Membraneshape cylindrical spear cylindrical,high-temperaturepHglass

Shaftmaterial glass glass glass,veryrobust

Electrodeplug S7 S7 S7withPG13,5threadedport

Diaphragm ceramic(self-cleaning) holeandceramic holeandceramic

Application generalpurposeapplications foodapplications onlinemeasurements

Table ......... ElectricalconnectionforpHelectrodes

Product number Description used with pH meter of...

16613-1EA-F 1mcoaxcable,ElectrodeplugS7,BNCinstrumentplug Beckmann,Corning,EDT,Fisher,Jenway,Hanna,Mettler-Toledo,Orion,Philips

30676-1EA-F 1mcoaxcable,ElectrodeplugS7,DIN19262instrumentplug Metrohm(oldertypes),Schott,WTW

49657-1EA 1mcoaxcable,ElectrodeplugS7,Metrohm(Lemo)instrumentplug Metrohm(pHmeter≤691)

41734-1EA 1mcoaxcable,ElectrodeplugS7,4mmBanana-connector -

8 Fluoroionophore for Mercury7-[3-(Dansylamido)propyl]-1-oxa-4,10-dithia-7-azacyclododecane,Selectophore®,≤97.0%(HPLC)(Fluka90913)

Optical sensors based on fluorescence measurementsarewell-knownanalyticaltoolsformonitoringlowlevelsofheavymetalions.IntheprecedingissueofAnalytix,we described a very selective fluorionophore for Ag+.Now,wearepleased topresentanothervery selectivefluoroionophore for the subnanomolar detection ofHg(II)ions,[12]aneNS2O[5].Thisfluoroionophorecanbeapplied to the direct determination of the mercurycontentofamalgamalloy,hair,wellwatersamplesandothersamples.

S

HN

S

O

S

N

O

O

NCH33H C

NN

O OCH 2(CH 2) 16CH3

CH

H3C

3

Figure 2 ......... [12]aneNS2O

CharacteristicsAnalyte:Hg2+

Indicator:[12]aneNS2O

Additive:KTpClB

Polymermatrix:PVC/NPOE

Sensitiverange:1.0x10_4to5.0x10

_12M(analyteinbuffer

pH3.3)

LOD:8.0x10_13M

lex[nm]:409.7(338inMeOH)

lem[nm]:523.3(495inMeOH)

Responsetime:<60s

Table ......... ProductTable:Hg2+ISE


90913 Fluka 7-[3-(Dansylamido)propyl]-1-oxa-4,10-dithia-7-azacyclododecane

25mg

60591 Fluka Potassiumtetrakis(4-chlorophenyl)borate(KTpClB)

100mg,1g,5g

73732 Fluka 2-Nitrophenyloctylether(NPOE) 5mL,25mL,100mL

81392 Fluka Poly(vinylchloride)highmolecularweight 1g,10g,50g

87369 Fluka Tetrahydrofuran 10mL,100mL,500mL

www.sigma-aldrich.com/sensoric

18Ti

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www.sigma-aldrich.com/hydranal

TheKarlFischer(KF)titrationfordeterminationofwaterinaldehydesandketonescanbechallenging.StandardKF titration uses methanol or methanol-containingsolvents inthetitrationvessel.Aldehydesandketonescanreactwiththeseconventionalreagents,undergoingnucleophilic addition reactions in methanol that formacetals or ketals and water (Figure 1). The liberatedwater leads to erroneously high results and vanishingend-points. Additionally, a second side reaction, thebisulfite addition, can occur during the titration ofaldehydes. This reaction consumes water from thesampleandleadstoerroneouslylowresults(Figure 2).Addressing this reactivity problem, Sigma-Aldrichresearchers developed methanol-free HYDRANAL®-Medium K andHYDRANAL®-Working Medium K.These reagents prevent adverse side reactions andeliminate or significantly reduce them as sources oferror.AninnovativeandpatentedformulationincludesspecificsolventsnotfoundincompetitiveKFreagents.

Elimination of nucleophilic addition using HYDRANAL®-Medium K and HYDRANAL®-Working Medium KThe elimination of methanol in both HYDRANAL®-Medium K and HYDRANAL®-Working Medium Kpresentsatwo-foldadvantage:Iteliminatesunwantedsidereactions,likenucleophilicaddition,anditimprovesthesolubilityofcertainsamples.Forexample,wefoundthatasmuchas5gof3-benzoylpropionicacidcanbetitratedinthesenewmediawithnegligibleformationofketals.

Prevention of bisulfite addition using HYDRANAL®-Composite 5KAsdiscussedpreviously,bisulfiteadditionisanunwantedsidereactionduringKFtitrationofaldehydes.Toavoidit,werecommendtheuseofHYDRANAL®-Composite5K as the titrating agent in combination withHYDRANAL®-Medium K or HYDRANAL®-WorkingMediumK.HYDRANAL®-Composite5KshowsaslowerreactionrateincomparisontoHYDRANAL®-Composite5,whichresultsinsuppressionofthebisulfiteadditionreaction.

Comparing HYDRANAL®-Medium K and HYDRANAL®-Working Medium KHYDRANAL®-Working Medium K contains 2-chloroethanolandisthereforecategorizedasverytoxic(T+). However, in HYDRANAL®-Medium K we havereplaced the 2-chloroethanol with less hazardousalcohols. Instead of toxic, HYDRANAL®-Medium K iscategorizedonlyasharmful(Xn)becauseitstillcontainschloroform.AbenefitoftheXncategorizationisfewershipping and packaging restrictions forHYDRANAL®-MediumK.

Althoughitissafer,HYDRANAL®-MediumKisequallyreactive as HYDRANAL®-Working Medium K. Bothprovideshorttitrationtimesandaccurateresults.UsingHYDRANAL®-Composite5Kasthetitratingagent,wecompared the results of titrations in both media onmany aldehydes and ketones. The results for arepresentativeselectionofketonesappear inTable 1.However, HYDRANAL®-Medium K does offerperformance advantages with very reactive aldehydessuch as propionaldehyde, butyraldehyde andcrotonaldehyde. Capacity and accuracy are alsoimprovedforothercompoundsincludingsalicylaldehyde,acetylacetone, 2,4-dihydroxyacetophenone and 2-benzolpyridine.

ResultsofourstudiescomparingHYDRANAL®-WorkingMediumKandHYDRANAL®-MediumKindicate:• Comparablesamplecapacityin30mLmedium• Comparableresultsforwatercontentandstandard

deviation• Comparabletitrationspeed• Comparable accuracy of recovery rate of added

wateraftersampletitration

HYDRANAL® Medium K ........ Efficaciousandnon-toxicKarlFischerreagentsforwaterdeterminationinaldehydesandketones

By Helga Hoffmann, Technical Service HYDRANAL® Manager …[email protected]

and Andrea Felgner, Product Manager Analytical Reagents …[email protected]

19

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www.sigma-aldrich.com/hydranal

For expert answers to all your KF titration questions, please contact our HYDRANAL® specialists:

Europe and the rest of the worldMs.HelgaHoffmannTechnicalServiceHYDRANAL®

WunstorferStraße40D-30926Seelze,GermanyTel.++49-5137/8238-353Fax++49-5137/8238-698e-mail:[email protected]

USA and CanadaMr.DougClarkHYDRANAL®TechnicalCenter545S.EwingAveSt.LouisMO63103Tollfree:(800)493-7262(USAandCanada)Fax:(314)286-6699e-mail:[email protected]

C

O

+2CH3OH

H+ C

OCH3

OCH3 +H2O

Figure 1 ......... Aldehydesandketonesundergonucleophilicadditionofmethanolresulting

informationofacetalorketalandwater

Figure 2 ......... Bisulfiteadditionreactionconsumeswater

C

O

+SO2+H2O+NR‘ R C

OH

SO3HNR‘

HRH

(NR’=base)

Substituting HYDRANAL®-Working Medium K with HYDRANAL®-Medium KIf you are using our original HYDRANAL®-WorkingMedium K for KF titration of aldehydes and ketones,newHYDRANAL®-MediumK isabetterchoice ifyouwishto• Improveworkplacesafety• PerformKFtitrationwithnon-toxicreagents• Reducethewasteofpackagingmaterial

HYDRANAL®-MediumKisafullyeffectivesubstitutetoHYDRANAL®-WorkingMediumK,providingequivalentspeed and accuracy for KF titrations. Additionally, itoffers significant application, safety and shippingbenefits.

HYDRANAL®-Medium K application: Water determination in benzaldehydeBecause reactivity of benzaldehyde is very high,HYDRANAL®-MediumKispreferredforitsKFtitration.30 mL HYDRANAL®-Medium K are added to thetitrationvesselandtitratedtodrynesswithHYDRANAL®-Composite 5K. 2 mL benzaldehyde are weighed bydifferenceandaddedtothevessel.ThewatercontentistitratedwithHYDRANAL®-Composite5K.

DetailsaboutHYDRANAL® reagents canbe foundbyvisitingournewly-designedWebpagewww.sigma-aldrich.com/hydranal

Table 1 ......... ComparisonofperformanceofHYDRANAL®-MediumKandHYDRANAL®-

WorkingMediumKforselectedketones

Sample (5 mL)

Titration time per sample (min.)

Water content % (mean, coeff. of variation) n = 5

Recovery rate of 1 mg water after one sample

Acetone

MediumK(non-toxic) 2 0.11%,CV0.24% 100.4%

WorkingMediumK 2 0.12%,CV1.00% 102.2%

4-Methyl-2-pentanone

MediumK(non-toxic) 0.8 0.009%,CV9.6% 99.8%

WorkingMediumK 1 0.007%,CV3.8% 99.8%

Cyclohexanone

MediumK(non-toxic) 1.5 0.021%,CV3.2% 100%

WorkingMediumK 1.5 0.025%,CV4.1% 102.9%

Acetophenone

MediumK(non-toxic) 1.5 0.076%,CV0.79% 98.9%

WorkingMediumK 1.5 0.075%,CV0.36% 100.7%

Table 2 ......... ProductListofselectedHYDRANAL®reagents

Cat. No. Brand Product Package Size

34698 Riedel-deHaën HYDRANAL®-MediumK 1L

34816 Riedel-deHaën HYDRANAL®-Composite5K 500mL,1L,2.5L

Gram-positiveCocci

CatalaseTest

negative positive

Streptococcussp.

growthonSheep’sBloodAgar

b-hemolytic a-hemolytic

GrowthinpresenceofBacitracinDiscs

GrowthinpresenceofOptochinDiscs

sensitive resistantsensitive

Streptococcuspyrogenes

otherb-hemolyticstreptococci

resistant

Streptococcuspneumoniae

othera-hemolyticstreptococci

Staphylococci

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www.sigma-aldrich.com/microbiology

Streptococci are non-motile, microaerophilic, Gram-positive sphericalbacteria (cocci). Theyoftenoccur aschainsorpairsandare facultativeor strictanaerobes.Streptococci give a negative catalase test, whilestaphylococci are catalase-positive. Because they areunabletosynthesizecytochromes,streptococcicannotcarry out oxidative phosphorylation. They are able toferment sugars, but the end product is always lacticacid.Therefore,streptococciareveryacidtolerantandcountamongthelacticacidbacteriaorder.

Therearemanynaturalsourcesofstreptococci,includinghumansanddiverseanimalswheretheyoftencolonizethe mucosal surfaces of the mouth, intestinal tract,nasalpassagesandpharynx.Thepresenceofstreptococciin drinking water indicates fecal contamination. Foodsources with high risk of contamination include milkanddairyproducts,eggs,steamedlobster,groundham,

potatosalad,custard,ricepuddingandshrimpsalad.Inmoststreptococcalfoodpoisoningcases,thefoodwasallowedtostandatroomtemperatureforseveralhoursbetween preparation and consumption. The conta-minationof the food ismostoften the resultofpoorhygiene,handlingofthefoodbyinfectedpeople,ortheuseofraw(unpasteurized)milk.Althoughtheycanbepotentpathogens,somestreptococciarecommerciallyimportant for the production of cheese and yogurt.TheseincludeS. lactis, S. cremoris, S. diacelillactisandS. thermophilus,thelatterbeingthemostwell-known.

Fordetection,identification,differentiation,enumerationandcultivationofstreptococci,Sigma-Aldrichprovidesabroad range of specific agars and broths (Table 1),Streptococci Diagnostic Tests (Table 2) and a Gramstainingkitandcomponentsolutions(Table 3).

Scientific classification of StreptococcusKingdom:EubacteriaPhylum:FirmicutesClass:BacilliOrder:LactobacillalesFamily:StreptococcaceaeGenus:Streptococcus

Grouping of Streptococci based on hemolytic activityStreptococci are divided into three groups based ontheir hemolytic (red blood cell lysing) activity. Thehemolytic reaction can be visualized on blood agarplates,suchasthenon-selectiveAgarsforDifferentiationthatarelistedinTable 1.

Alpha-Hemolytic StreptococciInalphahemolysis,theredbloodcellsremainintact,butthehemoglobinisconvertedtobiliverdin.Thiscausesagreeningofthebloodagarplatearoundthecolonies.

• Pneumococci S. pneumoniae: Causes bacterial pneumonia, otitis

mediaandmeningitis.S. pneumoniae sensitivity tooptochin (ethylhydrocupreinehydrochloride) is thebasisofadiagnostictest(Figure 1, Table 2).

• ViridansandOthers S. mutans:Associatedwithdentalcaries. S. viridans: Causative agent for endocarditis and

dentalabscesses.

Streptococci ........ Anoverviewofdetection,identification,differentiationandcultivationtechniques

By Jvo Siegrist, Product Manager Microbiology …[email protected]

Figure 1 .........

Differentiationand

identificationflowchart

ofGram-positivecocci

S. salivarius: Considered to be an opportunisticpathogen.

S. salivarius subsp. thermophilus: Used in theproductionofcheeseandyogurt.

Beta-Hemolytic StreptococciBetahemolysisisatruehemolysisoferythrocytesbytheenzymehemolysin.Clearzoneswillappeararoundthecolonies on the blood agar plate. Beta-hemolyticstreptococciarefurtherdividedintoserologicalgroupsusing specific antibodies that recognize surfacecarbohydrateantigens(e.g.A,B,etc.).

• GroupA S. pyogenes: Causes infections like strep throat,

acute rheumatic fever, scarlet fever, acuteglomerulonephritis and necrotizing fasciitis. It issensitivetobacitracin(Fig. 1),afactthatisemployedinaStreptococcusdiagnostictest(Table 2).

Other Streptococci species may also possess theGroup A antigen but are not human pathogens.TheseincludeS. dysgalactiae subsp. equisimilisandS. anginosusstrains.

21

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• GroupB S. agalactiae:Causesmeningitisinneonatesandthe

elderly. Occasionally colonizing the femalereproductivetract,theyincreasetheriskforprematurerupture of membranes and transmission of theinfectiontothechild.

• GroupC S. equi: Causesstranglesinfectioninhorses. S. zooepidemicus: Causesinfectionsincattle,horses

andothermammals.

• GroupD(Enterococci) Many former Group D streptococci have been

reclassified to the genus Enterococcus (e.g. S. faecalis, S. faciem, S. durans, S avium).

S. bovis and S. suis:StillintheGroupDstreptococci.Non-Hemolytic or Gamma-Hemolytic StreptococciGammahemolysisisamisnomerasthereisactuallynohemolysis.Non-hemolyticorgamma-hemolyticstrepto-coccirarelycausedisease.


Table 1 ......... MediaforStreptococci

Non-selective Enrichment Broths


53286 Fluka BrainHeartBroth

B2551 Sigma Brewerthioglycollatemedium

22089 Fluka CaseinpeptoneLecithinPolysorbateBroth

22098 Fluka CASOBroth

60865 Fluka CookedMeatBroth

17123 Fluka EllikerBroth

05121 Fluka HeartInfusionBroth

70122 Fluka NutrientBrothNo.1

70149 Fluka NutrientBrothNo.3

40893 Fluka PeptoneWater,phosphate-buffered,Vegitone

70179 Fluka PeptoneWater

77187 Fluka PeptoneWater,phosphate-buffered

S4681 Sigma StandardNutrientBrothNo.1

85905 Fluka StuartRingertzMedium

90404 Fluka ThioglycolateBrothwithResazurine

T1438 Sigma ToddHewittBroth

22092 Fluka TrypticSoyBroth

51228 Fluka TrypticSoyBrothNo.2

41298 Fluka TrypticSoyBroth,Vegitone

T3938 Sigma TryptoneSoyaBrothwithoutDextrose

T4407 Sigma TryptoseBroth

V5262 Sigma VealInfusionBroth

41960 Fluka VegitoneInfusionBroth

Selective Enrichment Broths


17157 Fluka GlucoseAzideBroth

Non-selective Agars for Cultivation, Enumeration and Isolation

A3340 Sigma ACAgar

70138 Fluka BrainHeartInfusionAgar

22095 Fluka CASOAgar

27688 Fluka ColumbiaAgar

D3060 Sigma Dextrosestarchagar

D8184 Sigma Diagnosticsensitivitytestagar

70147 Fluka MilkAgar

70148 Fluka NutrientAgar

17197 Fluka PeptonizedMilkAgar

70152 Fluka PlateCountAgar

88588 Fluka PlateCountAgaraccordingtoBuchbinderetal.

19718 Fluka PlateCountAgar,Vegitone

17257 Fluka StreptococcusthermophilusIsolationAgar

22091 Fluka TrypticSoyAgar

14432 Fluka TrypticSoyAgar,Vegitone

51414 Fluka TrypticSoyaAgarwithPolysorbate80andLecithin

70159 Fluka TryptoneGlucoseExtractAgar

T2313 Sigma TryptoseAgar

Non-selective Agars for Differentiation


70133 Fluka BloodAgar(Base)

B1676 Sigma BloodAgarBaseNo.2

55420 Fluka CLEDAgar

70136 Fluka DeoxyribonucleaseTestAgar

D2560 Sigma DNaseTestAgarwithToluidineBlue

17153 Fluka LSDifferentialAgar

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Selective Agars with Differential System for Differentiation, Detection and Isolation

06105 Fluka BileEsculinAzideAgar

17151 Fluka KanamycinEsculinAzideAgar

01337 Fluka MitisSalivariusAgar

Media for Sensitivity Testing

97580 Fluka Mueller-HintonAgar2

Table 2 ......... Diagnostictestsforidentificationanddifferentiationofstreptococci


88597 Fluka CatalaseTest

08382 Fluka BacitracinDisks

74042 Fluka OptochinDisks

67886 Fluka PYRaseStrips

Table 3 ......... Gramstainingkitandcomponentsolutions


77730 Fluka GramStainingKit

94448 Fluka Gram‘sCrystalvioletSolution

75482 Fluka Gram‘sDecolorizerSolution

87794 Fluka Gram’sFuchsinSolution

90107 Fluka Gram‘sIodineSolution

94635 Fluka Gram‘sSafraninSolution

Moredetailsaboutthemediaandtestscanbefoundonourwebsitewww.sigma-aldrich.com/microbiology

Bibliography[1] Patterson,M.J.Streptococcus.InBaron‘sMedicalMicrobiology;

4thed.;Baron,S.et al.,Eds.;Univ.ofTexasMedicalBranch,1996.

[2]Facklam,R.WhatHappenedtotheStreptococci:Overviewof

TaxonomicandNomenclatureChanges.Clin. Microbiol. Rev.,

2002,15(4),613–630.

[3]Getting,V. A.;Wheeler,S. M.;Foley,G. E. AFood-Borne

StreptococcusOutbreak.Am. J. Public. Health Nation’s Health,

1943,33(10),1217–1223.

The vast array of products for microbiology availabletoday,includingmedia,baseingredients,peptonesanddiagnostictests,callsforasearchtooltohelpanalystsmake the proper choice and save valuable time. Thenewly-designed Sigma-Aldrich Microbiology Nodeprovidessuchasolution.Ithelpsthemicrobiologistfindthe right products and information for their specificapplication, with all related products convenientlypresentedinoneview.

The node lists alphabetically the different base ingredients for media from diverse categories likeproteinsources,carbohydratesources,agars,bilesalts,etc.Searchescanberefined;forexample,“carbohydratesources”isdividedintocarbohydrateextractsandsugars.

Using the Media Explorer, growth media can besearched by field of application, microorganism,biochemicalidentificationtestmedia,alphabeticallyand

Newly-Designed Analytical Microbiology Node ........ Searchcapabilities,technicalresourcesandotherfeaturesmakeitanindispensabletoolforthepracticingmicrobiologist

By Jvo Siegrist, Product Manager Microbiology …[email protected]

othercriteria.Thenodealsolistsalltests(kits,discsandstrips) and reagents for microbe identification anddifferentiation. Another searchable group is theMicroscopy Reagents and Kits, which permitssearchingbystainingmethodormicroorganism.

TheMicrobiologyNodealsogivesanoverviewofSigma-Aldrich’s equipment for microbiology, includinganaerobic equipment, incubators, inoculation tools,petridishesandpetridishholders.

Lastly, the node is a valuable technical resource forinformationonbasicmicrobiologyandhowtoprepareandusemediaanddiagnostics.Besides literatureandreferences, useful links to information about QualityandQualityAssurancearefoundonthenode.

TestournewMicrobiologyNodetodayatwww.sigma-aldrich.com/microbiology.

23

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LC-MS solvents for normal phase chiral chromatography ........

Somechiralstationaryphases(CSP)dependonnormalphase mode with organic solvents, i.e. for warfarin.With standard conditions polarimetric detection tellswhichenantiomeriseluting,butitisbyfarnotsensitiveenoughfortheanalysisofbodyfluids,asforexamplefrom pharmacokinetic studies. Besides Fluorescence,

LC-MS detection with APCI or APPI ion sources thencouldbethemethodofchoice,whensuitableionizationconditions can be found. Sigma-Aldrich offers thesolvents for that purpose, n-hexane or n-heptane, 2-propanolandformicacidasadditive,allintestedhighLC-MSgradequality.

8 Environmental Standards from Sigma-Aldrich ........

Sigma-Aldrich is pleased to offer new standards forenvironmental analysis from three different productlines.PESTANAL®productsarehigh-puritystandardsofpesticides and their metabolites. In total this productlinecontainsmorethan1200analyticalstandards.The VETRANAL® product line contains high-puritystandardsoftheactiveingredientsofveterinarydrugs.

More than200analytical standards, belonging to thechemical classes of antibiotics and hormones, areoffered for forensics and residue analysis in the foodsectorand inenvironmentalanalytics.TheOEKANAL®product line – 400 products – consists of high-puritystandards of common pollutants and contaminantsanalyzedinenvironmentalsamples.

By Nicole Amann, Product Manager Analytical Standards … [email protected]

By Rudolf Koehling, Applications Development R&D, Sigma-Aldrich Switzerland … [email protected]

and Joachim Emmert, LC-MS Specialist, Klinkner & Partner … [email protected]

Table ......... LC-MScompatibleorganicsolventsandreagentsfornormalphasechiralchromatography

Cat. No. Brand Description Package Size Packaging Material

34986 Riedel-deHaën n-HexaneLC-MSCHRomAsoLv® 1L,2.5L Amberglassbottle

34999 Riedel-deHaën n-HeptaneLC-MSCHRomAsoLv® 1L,2.5L Amberglassbottle

34965 Riedel-deHaën 2-PropanolLC-MSCHRomAsoLv® 1L,2.5L Amberglassbottle

56302 Fluka Formicacid,purissp.a.,eluentadditiveforLC-MS 50mL HDPEbottle

Table ......... 8Riedel-deHaënBrandEnvironmentalStandards

Cat. No. Brand Description Product Line Package Size

33441 Riedel-deHaën Imidocarbdipropionate VETRANAL® 50mg

33613 Riedel-deHaën Dichlormid PESTANAL® 100mg

34085 Riedel-deHaën Ethychlozate PESTANAL® 100mg

34232 Riedel-deHaën Prothioconazol PESTANAL® 100mg

33577 Riedel-deHaën Microcystin-RR10µg/mLinMethanol OEKANAL® 1mL

33576 Riedel-deHaën Microcystin-YR5µg/mLinMethanol OEKANAL® 1mL

33941 Riedel-deHaën Thionazin PESTANAL® 50mg

34235 Riedel-deHaën Clostebol PESTANAL® 100mg

32949 Riedel-deHaën Propylenethiourea PESTANAL® 25mg

33447 Riedel-deHaën Mecillinam VETRANAL® 100mg

33943 Riedel-deHaën Dimepiperate PESTANAL® 100mg

34237 Riedel-deHaën Cinmethylin(mixofisomers) PESTANAL® 50mg

33587 Riedel-deHaën Fonofos-solution100ng/µLinAcetonitrile PESTANAL® 2mL

34238 Riedel-deHaën Bismerthiazol PESTANAL® 100mg

33702 Riedel-deHaën PCB-44 OEKANAL® 10mg

33448 Riedel-deHaën NequinateorMethylbenzoquate VETRANAL® 10mg

33944 Riedel-deHaën Leucomalachitgreen-d6 OEKANAL® 10mg

33454 Riedel-deHaën Potassiumclavulanate VETRANAL® 100mg

34239 Riedel-deHaën Cloquintocet PESTANAL® 25mg

34229 Riedel-deHaën (Z)-Metominostrobin PESTANAL® 10mg

34233 Riedel-deHaën Dicamba-d3 PESTANAL® 10mg

34089 Riedel-deHaën FosfomycinSodium VETRANAL® 100mg

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Residual Solvents from Food Packaging Materials

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