High Sensitivity and Rugged Pesticide Residue …...High Sensitivity and Rugged Pesticide Residue...
Transcript of High Sensitivity and Rugged Pesticide Residue …...High Sensitivity and Rugged Pesticide Residue...
High Sensitivity and Rugged Pesticide
Residue Analysis in Food Samples by
GC/MS Triple Quadrupole
EPRW June 2010Dr. Finbarr O’Regan
Pesticide Control Service,
Department of Agriculture, Fisheries and Food,
Backweston Campus,
Young’s Cross,
Celbridge,
Co. Kildare
• Extraction Methods
• Compound optimisation
• Retention Time Locking
• Limits of Detection
• Linearity
Overview
Agilent 7000A Triple Quadrupole GC/MS
Fruit and veg. Extraction
• Mini-Luke extraction
• Acetone , DCM, Petroleum Ether
• Sodium Sulphate
• GPC Clean-up (also run without GPC)
• Samples made up and run in Ethyl Acetate• Based on standard multi-residue method published as "Analytical
methods for pesticide residues in foodstuffs" 6th Ed. Ministry of Health
Welfare and Sport - The Netherlands
Fat matrix Extraction
• Acetone , Acetonitrile
• Celite clean-up
• GPC Clean-up
• Samples made up and run in Ethyl Acetate
• Based on standard multi-residue method published as "Manual of Pesticide
Analysis - Vol 1" DFG - Deutsche Forschungsgemeinschaft
Milk and Egg extraction
• QuEChERS extraction
• Acetonitrile
• Sodium Acetate/Acetic Acid Buffer,
Magnesium Sulphate and Sodium
Chloride
• Samples made up and run in Ethyl Acetate
• Based on standard multi-residue method published as J. AOAC Int. 88 615-
629 - Steven J. Lehotay, Katerina Mastrovska & Alam R. Lightfield
Optimisation
• 200 compounds in two runs
• Retention Time Locking– Locked to pp-dde
• Limits of Detection– 10ppb for 178 compounds
– 20 - 50ppb for remaining 22 compounds
• Linearity– R2 = 0.999
– (captan and captafol – can be problematic)
GC-QqQ Method Overview
Internal Standard TPP
Quantitation Method
Calibration
Qualifier
Malathion LCL (10ppb)
Malathion Positive
Chlorpyriphos LCL (10ppb)
Chlorpyrifos Positive
EUPT FV11 Cauliflower Matrix
z-scores
MiniLuke
No GPC EU Median
Mini LukeGC-MSD
No GPCGC-QqQ
azinphos-methyl 0.316 0.409 0.355 -0.44 0.61
Boscalid 0.347 0.495 0.414 -0.65 0.78
buprofezin 0.477 0.681 0.638 -1.01 0.27
cadusofos 0.598 0.639 0.611 -0.09 0.18
carbofuran 0.231 0.218 0.283 -0.73 -0.92
EUPT FV11 Cauliflower Matrix
z-scores
MiniLuke
No GPC EU Median
Mini LukeGC-MSD
No GPCGC-QqQ
deltamethrin 0.144 0.162 0.157 -0.33 0.13
diazinon 1.120 1.550 1.250 -0.42 0.96
isofenphos-methyl 0.411 0.570 0.540 -0.96 0.22
l-cyhalothrin 0.213 0.252 0.266 -0.80 -0.21
metaxyl 0.519 0.460 0.450 0.61 0.09
EUPT FV11 Cauliflower Matrix
z-scores
MiniLuke
No GPC EU Median
Mini LukeGC-MSD
No GPCGC-QqQ
methamidophos 0.416 0.387 0.405 0.11 -0.18
methidathion 0.446 0.528 0.472 -0.22 0.47
monocrotophos 0.516 0.420 0.438 0.71 -0.16
sum parathion-methyl 0.358 0.226 0.320 0.48 -1.18
phosalone 0.285 0.412 0.368 -0.90 0.48
EUPT FV11 Cauliflower Matrix
z-scores
MiniLuke No GPC
EU Median
MiniLuke No GPC
procymidone 0.676 0.811 0.780 -0.53 0.16
triazophos 0.450 0.631 0.538 -0.65 0.69
Thank you for your attention …
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