Determination of metabolic and hydrolytic products of organophosphorus pesticide chemicals in human blood and urine

Shafik, M. T.; Enos, Henry F.

doi:10.1021/jf60166a039

Cited by 68 publications

(28 citation statements)

References 3 publications

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“…Under these stress conditions recovery values for DETP, on contrary, decreased. This might be explained by the chemical instability of alkyl (thio)phosphates in strongly acidic media at elevated temperatures as addressed previously [16,42]. The increase of the recovery of DEP let assume that DETP is partly converted to DEP.…”

Section: Sample Clean-up and Extraction Efficiencymentioning

confidence: 82%

Determination of chlorpyrifos metabolites in human urine by reversed-phase/weak anion exchange liquid chromatography–electrospray ionisation–tandem mass spectrometry

Bicker

Lämmerhofer

Lindner

2005

Journal of Chromatography B

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Section: Sample Clean-up and Extraction Efficiencymentioning

confidence: 82%

Determination of chlorpyrifos metabolites in human urine by reversed-phase/weak anion exchange liquid chromatography–electrospray ionisation–tandem mass spectrometry

Bicker

Lämmerhofer

Lindner

2005

Journal of Chromatography B

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“…The urine was freeze -dried and derivatized using benzyltolyltriazine reagent ( Daughton et al, 1979;Takade et al, 1979 ). A saturated salt solution was added to the tubes and the benzyl derivatives were extracted using cyclohexane and analyzed by gas chromatography with flame photometric detection (GC /FPD ) (Shafik and Enos, 1969;Lores and Bradway, 1977 ).…”

Section: Methodsmentioning

confidence: 99%

Pesticide exposure and creatinine variation among young children

O'Rourke

Lizardi

Rogan

et al. 2000

J Expo Sci Environ Epidemiol

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Pesticide exposure may differentially impact young children; they live closer to the ground and take in greater amounts of food relative to body mass than older children or adults. We are using an organophosphate ( OP ) urinary biomarker screen ( gas chromatography with flame photometric detection, GC / FPD ) to evaluate pesticide exposure among 154 children 6 years of age living in a heavily farmed border ( US ± Mexico ) community. The screen detects diethylphosphates ( DEPs ) and dimethylphosphates ( DMPs ) above a reference range of 1000 non -occupationally exposed individuals ( DL= 25 g / g creatinine, Cr ) . At least one metabolite was detected for 33% of the subjects; many samples contained multiple biomarkers. DEP was detected in 5% of the subjects. DMP and DMTP were frequently measured ( 25% and 26%, respectively ) . Biomarker concentrations are adjusted by the body's metabolism of Cr as an indicator of urine dilution. Cr concentrations were examined separately to evaluate their effect on internal dose measures. Cr concentrations were significantly different by season ( K ± W = 0.83, P= 0.022 ) . Significant differences exist between the autumn:spring ( P= 0.038 ) Cr concentrations and between summer:autumn ( P= 0.041 ) Cr concentrations based on Mann ± Whitney U = 1070.5, z = À 2.041, ( P= 0.041 ) . Our analysis of NHANES III data did not reflect seasonal Cr differences for 6 year olds. No younger children were included. Absorbed daily dose ( ADD ) estimates were calculated for children with the highest concentrations of metabolite. Calculations are theoretical values assuming that the entirety of a given metabolite was metabolized from a single pesticide. Several class -appropriate pesticides were evaluated. For the children with the highest levels, almost all estimated ADDs exceeded the RfD. Although the actual metabolite concentrations dropped appreciably, ADD were still exceeded RfDs at the 95th percentile. The urinary OP screen was effective in identifying subjects with atypical internal doses. Daily Cr yield is a critical component in ADD calculations. Cr variability produces differences in internal dose measurement and estimates of ADD independent of exposure. Cr variability among young children needs to be examined, and caution should be applied when evaluating Cr adjusted internal doses for children. Journal of Exposure Analysis and Environmental Epidemiology ( 2000 ) 10, 672 ± 681.

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“…It is thus evident that a major amount of it used in agroforestry or for medical purposes remains exposed to the environment. Bio-monitoring exposures to malathion has been accomplished by the determination of dimethyl thiophosphate (DMTP), dimethyldithiophosphate (DMDTP) (Shafik and Enos, 1969;Shafik et al, 1971Shafik et al, , 1973 or the carboxylesterase metabolites, malathion ␣-monoacid (␣-MMA) and malathion diacid (MDA) (Bradway and Shafik, 1977). Muan and Share (1987) have described an anion exchange, solid phase extraction procedure for malathion metabolites.…”

Section: Introductionmentioning

confidence: 99%

Identification of metabolites of malathion in plant, water and soil by GC-MS

Kaur¹,

Mathur

Tandom

et al. 1997

Biomed. Chromatogr.

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Metabolism of malathion (O,O,‐dimethyl S‐[1,2‐bis(ethoxy carbonyl)‐ethyl]phosphorodithioate) has been studied in plants, water and soil. A number of products identified by gas chromatography–mass spectrometry (GC–MS), have been formed by de‐esterification, oxidation and hydrolysis of malathion. Hydrolysis of the P–S and C–S bonds occur in alkaline pH 8.0 and acidic pH 5.5, respectively. © 1997 John Wiley & Sons, Ltd.

show abstract

Determination of metabolic and hydrolytic products of organophosphorus pesticide chemicals in human blood and urine

Cited by 68 publications

References 3 publications

Determination of chlorpyrifos metabolites in human urine by reversed-phase/weak anion exchange liquid chromatography–electrospray ionisation–tandem mass spectrometry

Determination of chlorpyrifos metabolites in human urine by reversed-phase/weak anion exchange liquid chromatography–electrospray ionisation–tandem mass spectrometry

Pesticide exposure and creatinine variation among young children

Identification of metabolites of malathion in plant, water and soil by GC-MS

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