Multiresidue analysis of organophosphate and pyrethroid pesticides in duplicate-diet solid food by pressurized liquid extraction.
An analytical method was developed for determining organophosphate pesticides (OPP) and pyrethroid pesticides (PYR) in duplicate-diet solid food. The method consisted of pressurized liquid extraction (PLE) with dichloromethane followed by cleanup with gel permeation and solid phase extraction columns and gas chromatography/mass spectrometry (GC/MS) analysis. Quantitative recoveries (73-117 %) of the target pesticides were obtained for spiked duplicate-diet food samples. The percent standard deviation (% RSD) of replicate food samples was within ± 20 %. Another method was developed for determining a common OPP metabolite, 3, 5, 6-trichloro-2-pyridinol (TCP) in duplicate-diet food. The method consisted of a PLE with methanol followed by liquid-liquid partitioning, derivatization, and GC/MS analysis. Recoveries of TCP ranged from 83 to 101 % for spiked duplicate-diet food samples. The % RSD of replicate food samples was within ± 15 %. The results confirmed that these methods are reliable and robust, and that they can be used in routine analysis. In addition, a storage stability study for a common OPP, chlorpyrifos (CPF), in solid food samples was performed. The fortified (15)N-(13)C-labeled CPF was stable over 16 mo storage at -20° C in the dark. The developed analytical methods were successfully applied to 278 duplicate-diet food samples from preschool children, demonstrating that these methods are robust and suitable for routine analysis in future exposure monitoring studies.
Chuang
Jane C
JC
Battelle, Columbus, Ohio, USA. chuangj@battelle.org
Wilson
Nancy K
NK
D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D009943:Organophosphorus Compounds / Q000032:analysis / Q000302:isolation & purification*; D010573:Pesticide Residues / Q000032:analysis / Q000302:isolation & purification*; D011722:Pyrethrins / Q000032:analysis / Q000302:isolation & purification*
D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D011722:Pyrethrins