Abstract
A rugged and sensitive method was developed to monitor urinary concentrations of O,S-dimethyl hydrogen phosphorothioate (O,S-DMPT), a specific biomarker of exposure to the organophosphate insecticide methamidophos. After pH adjustment and C18 solid phase extraction column cleanup, the urine was lyophilized at a low temperature to prevent loss of possibly highly volatile and unstable O,S-DMPT metabolite. The dried residue was derivatized using N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide and 1% tert-butyldimethylchlorosilane (MTBSTFA + 1% TBDMCS) in acetonitrile. After it was filtered, the derivatized product was analyzed and quantified by gas chromatography using a pulse flame photometric detector specific for phosphorus compounds. The limit of detection for this method was 0.004 ppm with a limit of quantitation of 0.02 ppm of urine. The mean recovery value for O,S-DMPT from 17 urine samples fortified at varying concentrations was 108% with a standard deviation of 12%.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
