title: Quantification of six herbicide metabolites in human urine.
abstract: We developed a sensitive, selective and precise method for measuring herbicide metabolites in human urine. Our method uses automated liquid delivery of internal standards and acetate buffer and a mixed polarity polymeric phase solid phase extraction of a 2 mL urine sample. The concentrated eluate is analyzed using high-performance liquid chromatography-tandem mass spectrometry. Isotope dilution calibration is used for quantification of all analytes. The limits of detection of our method range from 0.036 to 0.075 ng/mL. The within- and between-day variation in pooled quality control samples range from 2.5 to 9.0% and from 3.2 to 16%, respectively, for all analytes at concentrations ranging from 0.6 to 12 ng/mL. Precision was similar with samples fortified with 0.1 and 0.25 ng/mL that were analyzed in each run. We validated our selective method against a less selective method used previously in our laboratory by analyzing human specimens using both methods. The methods produced results that were in agreement, with no significant bias observed.
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, Mailstop F17, Atlanta, GA 30341, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Norrgran
authors.forename: Roberto
authors.initials: R
authors.lastname: Bravo
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Bishop
authors.forename: Paula
authors.initials: P
authors.lastname: Restrepo
authors.forename: Ralph D
authors.initials: RD
authors.lastname: Whitehead
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
authors.forename: Dana B
authors.initials: DB
authors.lastname: Barr
mesh_terms: D015085:2,4,5-Trichlorophenoxyacetic Acid / Q000378:metabolism / Q000652:urine; D015084:2,4-Dichlorophenoxyacetic Acid / Q000378:metabolism / Q000652:urine; D000081:Acetamides / Q000378:metabolism / Q000652:urine; D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine; D001280:Atrazine / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006540:Herbicides / Q000378:metabolism / Q000652:urine*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D014052:Toluidines / Q000378:metabolism / Q000652:urine
chemical_list: D000081:Acetamides; D006540:Herbicides; D014052:Toluidines; C112862:atrazine mercapturate; C000188:alachlor; D015084:2,4-Dichlorophenoxyacetic Acid; C043377:acetochlor; D015085:2,4,5-Trichlorophenoxyacetic Acid; D001280:Atrazine; D000111:Acetylcysteine; C051786:metolachlor