Cleanup procedure for the determination of low levels of alkyl phosphates, thiophosphates, and dithiophosphates in rat and human urine

Shafik, M. T.; Bradway, Diane E.; Enos, Henry F.

doi:10.1021/jf60177a045

Cited by 37 publications

(19 citation statements)

References 3 publications

(8 reference statements)

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“…Analyses were undertaken by ID GC-MS/MS to evaluate background levels of six organophosphate metabolites: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), dimethylthiophosphate (DMTP), and dimethyldithiophosphate (DMDTP). These metabolites are common to 1 or more of 28 different organophosphates, as shown in Table 1, and have been measured extensively in biological samples as specific indicators of both occupational and environmental exposure to organophosphate pesticides (38)(39)(40)(41)(42)(43).…”

Section: Methodsmentioning

confidence: 99%

Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.

Whyatt

Barr

2001

Environ Health Perspect

144

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Experimental data have linked exposure to prenatal organophosphates to adverse neurocognitive sequalae. However, epidemiologic research has been hampered by lack of reliable dosimeters. Existing biomarkers reflect short-term exposure only. Measurements of pesticides in postpartum meconium may yield a longer-term dosimeter of prenatal exposure. As the initial step in biomarker validation, this research determined background levels, detection limits, and stabilities of six organophosphate metabolites in meconium: diethylphosphate (DEP), diethylthiophosphate (DETP), diethyldithiophosphate (DEDTP), dimethylphosphate (DMP), dimethylthiophosphate (DMTP), and dimethyldithiophosphate (DMDTP). Calibration curves were also constructed. The meconium was collected from 20 newborns at New York Presbyterian Hospital; analyses were undertaken at the Centers for Disease Control and Prevention (CDC). DEP was detected in 19/20 samples (range 0.8-3.2 microg/g) and DETP was detected in 20/20 (range 2.0-5.6 microg/g). DMP and DEDTP were each detected in 1/20 (at 16 and 1.8 microg/g, respectively). DMTP and DMDTP were not detected. Detection limits were comparable to or lower than those in urine; levels were similar to those seen in adult urine in population-based research. Metabolites were stable at room temperature over 12 hr. Calibration curves were linear over the range tested (0.5-400 microg/g); recoveries ranged from 18% to 66%. Using isotope dilution, recoveries of each analyte in individual samples can be corrected automatically based on the recovery of the respective stable isotope-labeled analogue, making this method fully quantitative. Results indicate that measurements of organophosphate metabolites in meconium have promise as biomarkers of prenatal exposure. Further research is needed to determine the time frame of exposure represented by pesticide levels in meconium and to evaluate the dose-response relationship.

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Section: Methodsmentioning

confidence: 99%

Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.

Whyatt

Barr

2001

Environ Health Perspect

144

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“…Occupational human exposure to OPs is usually evaluated by determination of the decrease of cholinesterase activity in blood between pre-and post-exposure, since it has large interindividual variability [8,9]. However, this indicator is not sensitive enough to monitor the body burden of OPs in the general population, and blood collection from many people is not always feasible.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous determination of urinary dialkylphosphate metabolites of organophosphorus pesticides using gas chromatography–mass spectrometry

Ueyama

Saito

Kamijima

et al. 2006

Journal of Chromatography B

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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

Cleanup procedure for the determination of low levels of alkyl phosphates, thiophosphates, and dithiophosphates in rat and human urine

Cited by 37 publications

References 3 publications

Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.

Measurement of organophosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study.

Simultaneous determination of urinary dialkylphosphate metabolites of organophosphorus pesticides using gas chromatography–mass spectrometry

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

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