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Direct determination of alkyl phosphates in human urine by liquid chromatography/electrospray tandem mass spectrometry

Direct determination of alkyl phosphates in human urine by liquid chromatography/electrospray... A novel and rapid procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the determination of dialkyl phosphates (metabolites of organophosphorus pesticides) in human urine has been developed. After addition of 40 mM tetrabutylammonium acetate, 10 µL of urine sample were directly injected into the LC/MS/MS system. The method was validated yielding calibration curves with correlation coefficients greater than 0.997 and repeatability coefficient of variation (CV) lower than 9%. The accuracy and precision were evaluated by direct injection of spiked samples at 10 and 100 µg/L obtaining recoveries between 78 and 119% with coefficients of variation below 12%. Limits of detection of 1 µg/L for diethyl phosphate (DEP), diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP) and 2 µg/L for dimethyldithiophosphate (DMDTP) were achieved, all the analytes being detected in negative ion mode. The fragmentation pathway of dialkyl phosphates allowed us the use of an additional transition for confirmation in order to improve their identification in real‐world samples. The applicability of the LC/MS/MS method was demonstrated by applying it to the analysis of urine samples of farmers exposed to the organophosphorus pesticide chlorpyrifos. Good correlation between application of the product in the field (citrus orchards), concentration levels of dialkyl phosphates and levels of the chlorpyrifos‐specific metabolite (1,3,5‐trichloro‐2‐pyridinol) was obtained. Copyright © 2002 John Wiley & Sons, Ltd. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Rapid Communications in Mass Spectrometry Wiley

Direct determination of alkyl phosphates in human urine by liquid chromatography/electrospray tandem mass spectrometry

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References (26)

Publisher
Wiley
Copyright
Copyright © 2002 Wiley Subscription Services
ISSN
0951-4198
eISSN
1097-0231
DOI
10.1002/rcm.790
pmid
12207365
Publisher site
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Abstract

A novel and rapid procedure based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the determination of dialkyl phosphates (metabolites of organophosphorus pesticides) in human urine has been developed. After addition of 40 mM tetrabutylammonium acetate, 10 µL of urine sample were directly injected into the LC/MS/MS system. The method was validated yielding calibration curves with correlation coefficients greater than 0.997 and repeatability coefficient of variation (CV) lower than 9%. The accuracy and precision were evaluated by direct injection of spiked samples at 10 and 100 µg/L obtaining recoveries between 78 and 119% with coefficients of variation below 12%. Limits of detection of 1 µg/L for diethyl phosphate (DEP), diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP) and 2 µg/L for dimethyldithiophosphate (DMDTP) were achieved, all the analytes being detected in negative ion mode. The fragmentation pathway of dialkyl phosphates allowed us the use of an additional transition for confirmation in order to improve their identification in real‐world samples. The applicability of the LC/MS/MS method was demonstrated by applying it to the analysis of urine samples of farmers exposed to the organophosphorus pesticide chlorpyrifos. Good correlation between application of the product in the field (citrus orchards), concentration levels of dialkyl phosphates and levels of the chlorpyrifos‐specific metabolite (1,3,5‐trichloro‐2‐pyridinol) was obtained. Copyright © 2002 John Wiley & Sons, Ltd.

Journal

Rapid Communications in Mass Spectrometry – Wiley

Published: Jan 30, 2002

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