Evaluation of supercritical fluid chromatography coupled ...€¦ · Supercritical fluid...
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0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 min 5.0 0 2.5 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 Intensity x 10,000 Results and discussion The matrix effect study revealed that the percentages of pesticides with irrelevant matrix effect (suppression lower than 20 %) was 99 % in tomato, 87 % in orange and 62 % in leek, whereas significant suppression (higher than 50 %) was not found in tomato and only 1 % of the compounds in orange and 3 % in leek (Figure 4). These results compare favorably with that typically obtained in LC–MS/MS. Figure 4: Matrix-effect (164 pesticides). The absence of water in the mobile phase also provided some important advantages regarding LC–MS/MS as (i) higher retention of polar compounds in the column, which elute with high sensitivity and good peak shape and (ii) a general increase of the sensitivity of the analysis, consequence of the high ionization and ion extraction efficiency (Figure 3). Pesticides evaluated were identified following the SANTE/11813/2017. At the spiking concentration of 5 μg/kg, 98 % of the pesticides were identified in tomato, 98 % in orange and 94 % in leek, whereas for the concentration of 10 μg/kg all the compounds were identified in tomato and only spiromesifen was not identified in orange and leek. At the concentration of 20 μg/kg, spiromesifen was also identified in these two matrices. The linearity and reproducibility of the method were evaluated with results which guarantee high quality in the analytical measurements. Even though only 2 μL of final extract were injected, the sensitivity of the SFC method was enough to achieve stringent LOQs. Real samples, including 6 different fruits and vegetables, were analyzed by the SFC-MS/MS proposed method, the results being similar to those obtained by LC–MS/MS. Figure 5: 164 pesticides spiked at the default MRL of 0.01 mg/kg (orange matrix).Quantifier ion is shown. Conclusion Carbon dioxide as mobile phase with methanol as modifier can represent a good alternative to LC-MS/MS with reduction of matrix effects and shorter run times. Reference V. Cutillas, M. M. Galera, Ł. Rajski, A. R. Fernández-Alba, J. Chrom. A, 2018, 1545, 67-74 Last eluting compound at 7.19 min Polar compounds Introduction Supercritical fluid chromatography coupled to triple quadrupole mass spectrometry (SFC-MS/MS, Nexera UC with LCMS-8060, Shimadzu Corporation, Kyoto, Japan) has been evaluated for pesticide residues in food. In order to check its advantages and limitations it was developed a method to identify and quantify 164 pesticides in three different matrices (tomato, orange and leek). Materials and Methods A carbon dioxide gradient with methanol (containing 1 mM ammonium formate) was used allowing a flow rate of 1.5 mL/min that made the total run time of 12 min without any problem of overpressure. Addition of a post column flow 150 μL/min of methanol with ammonium formate / formic acid was necessary to improve the ionization (Figure 2). Figure 1: Top: Shimadzu Nexera UC with triplequadrupole mass spectrometer Shimadzu LCMS-8050. Bottom: LC/SFC-MS/MS switching system for automatic change between LC- and SFC-MS/MS. Figure 2: SFC-MS/MS conditions and system configuration Figure 3: Examples of some compounds that increase their sensitivity using SFC-MS/MS. 100 µg/kg tomato. Evaluation of supercritical fluid chromatography coupled to tandem mass spectrometry for pesticide residues in food V. Cutillas 1 , M. M. Galera 1 , Ł. Rajski 1 , A. R. Fernández-Alba 1 European Union Reference Laboratory for Pesticide Residues in Fruit & Vegetables (EURL-FV), University of Almeria, Agrifood Campus of International Excellence (ceiA3) Department of Hydrogeology and Analytical Chemistry, Almería/ES HPLC system LC/SFC switching system SFC system Injection volume: 2 µL 40 ºC BPR pressure: 150 bar BPR Temperature: 50 ºC MeOH 1 mM HCOONH 4 MeOH 5 mM HCOONH4 0.1 % HCOOH ESI polarity: positive and negative FLOW 1.5 mL/min CO 2 pump Modifier pump LCMS-8060 Modifier solvent CO 2 cylinder Column oven Autosampler Backpressure regulator 2,4-D Fluazifop MCPA RT: 5.568 min SFC LC SFC LC SFC LC RT: 3.741 min RT: 5.036 min RT: 7.343 min RT: 7.494min RT: 7.481 min 8,2x10 4 8,2x10 4 1,7x10 5 1,7x10 5 5,9x10 4 5,9x10 4 0 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000 0 50 100 150 200 250 300 350 400 450 500 Tomato Orange Leek Carbaryl Proquinazid 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Number of pesticides with ion suppression Ion suppression 0 2000000 4000000 6000000 8000000 10000000 12000000 0 50 100 150 200 250 300 350 400 450 500 Tomato Orange Leek 0-20 % 20-50 % >50 % Tomato Orange Leek
Transcript of Evaluation of supercritical fluid chromatography coupled ...€¦ · Supercritical fluid...
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Results and discussion
The matrix effect study revealed that the percentages of pesticides withirrelevant matrix effect (suppression lower than 20 %) was 99 % in tomato,87 % in orange and 62 % in leek, whereas significant suppression (higherthan 50 %) was not found in tomato and only 1 % of the compounds inorange and 3 % in leek (Figure 4). These results compare favorably withthat typically obtained in LC–MS/MS.
Figure 4: Matrix-effect (164 pesticides).
The absence of water in the mobile phase also provided some importantadvantages regarding LC–MS/MS as (i) higher retention of polarcompounds in the column, which elute with high sensitivity and good peakshape and (ii) a general increase of the sensitivity of the analysis,consequence of the high ionization and ion extraction efficiency (Figure 3).Pesticides evaluated were identified following the SANTE/11813/2017. Atthe spiking concentration of 5 μg/kg, 98 % of the pesticides were identified intomato, 98 % in orange and 94 % in leek, whereas for the concentration of10 μg/kg all the compounds were identified in tomato and only spiromesifenwas not identified in orange and leek. At the concentration of 20 μg/kg,spiromesifen was also identified in these two matrices. The linearity andreproducibility of the method were evaluated with results which guaranteehigh quality in the analytical measurements. Even though only 2 μL of finalextract were injected, the sensitivity of the SFC method was enough toachieve stringent LOQs. Real samples, including 6 different fruits andvegetables, were analyzed by the SFC-MS/MS proposed method, theresults being similar to those obtained by LC–MS/MS.
Figure 5: 164 pesticides spiked at the default MRL of 0.01 mg/kg (orange matrix).Quantifier ion is shown.
Conclusion
Carbon dioxide as mobile phase with methanol as modifier can represent agood alternative to LC-MS/MS with reduction of matrix effects and shorterrun times.
Reference
V. Cutillas, M. M. Galera, Ł. Rajski, A. R. Fernández-Alba, J. Chrom. A, 2018,1545, 67-74
Last eluting compound at 7.19 min
Polar compounds
Introduction
Supercritical fluid chromatography coupled to triple quadrupole massspectrometry (SFC-MS/MS, Nexera UC with LCMS-8060, ShimadzuCorporation, Kyoto, Japan) has been evaluated for pesticide residues infood. In order to check its advantages and limitations it was developed amethod to identify and quantify 164 pesticides in three different matrices(tomato, orange and leek).
Materials and Methods
A carbon dioxide gradient with methanol (containing 1 mM ammoniumformate) was used allowing a flow rate of 1.5 mL/min that made the total runtime of 12 min without any problem of overpressure. Addition of a postcolumn flow 150 μL/min of methanol with ammonium formate / formic acidwas necessary to improve the ionization (Figure 2).
Figure 1: Top: Shimadzu Nexera UC with triplequadrupole massspectrometer Shimadzu LCMS-8050. Bottom: LC/SFC-MS/MS switchingsystem for automatic change between LC- and SFC-MS/MS.
Figure 2: SFC-MS/MS conditions and system configuration
Figure 3: Examples of some compounds that increase their sensitivity usingSFC-MS/MS. 100 µg/kg tomato.
Evaluation of supercritical fluid chromatography coupled to tandem mass spectrometry for pesticide residues in foodV. Cutillas1, M. M. Galera1, Ł. Rajski1, A. R. Fernández-Alba1
European Union Reference Laboratory for Pesticide Residues in Fruit & Vegetables (EURL-FV), University of Almeria, Agrifood Campus of International Excellence (ceiA3) Department of Hydrogeology and Analytical Chemistry, Almería/ES
HPLC system
LC/SFC switching system
SFC system
Injection volume: 2 µL
40 ºC
BPR pressure: 150 barBPR Temperature: 50 ºC
MeOH 1 mM HCOONH4
MeOH 5 mM HCOONH4 0.1 % HCOOH
ESIpolarity:
positive and negative
FLOW 1.5 mL/min
CO2
pump
Modifierpump
LCMS-8060
Modifier solventCO2
cylinder
Column ovenAutosampler
Backpressure regulator
2,4-DFluazifop MCPA
RT: 5.568 min
SFC LCSFC LC SFC LC
RT: 3.741 min RT: 5.036 minRT: 7.343 minRT: 7.494min RT: 7.481 min
8,2x104 8,2x1041,7x105 1,7x105 5,9x104 5,9x104
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