title: Quantification of phenolic metabolites of environmental chemicals in human urine using gas chromatography-tandem mass spectrometry and isotope dilution quantification.
abstract: We have developed a method to measure 12 urinary phenolic metabolites of pesticides or related chemicals. The target chemicals for our method are 2-isopropoxyphenol; 2,4-dichlorophenol; 2,5-dichlorophenol; carbofuranphenol; 2,4,5-trichlorophenol; 2,4,6-trichlorophenol; 3,5,6-trichloro-2-pyridinol; para-nitrophenol, ortho-phenylphenol, pentachlorophenol, 1-naphthol and 2-naphthol. The sample preparation involves enzyme hydrolysis, isolation of the target chemicals using solid phase extraction cartridges, a phase-transfer catalyzed derivatization, cleanup using sorbent-immobilized liquid/liquid extraction cartridges, and concentration of the sample. Derivatized samples are analyzed by capillary gas chromatography-tandem mass spectroscopy using isotope dilution calibration for quantification. The limits of detection are in the mid ng/L range and the average coefficient of variation was below 15% for most of the analytes. Using our method, we measured concentrations of the target chemicals in urine samples from the general population.
authors.affiliation: National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy., NE, Mailstop F-17, Atlanta, GA 30341, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bravo
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Caltabiano
authors.forename: Carolina
authors.initials: C
authors.lastname: Fernandez
authors.forename: Kimberly D
authors.initials: KD
authors.lastname: Smith
authors.forename: Maribel
authors.initials: M
authors.lastname: Gallegos
authors.forename: Ralph D
authors.initials: RD
authors.lastname: Whitehead
authors.forename: Gayanga
authors.initials: G
authors.lastname: Weerasekera
authors.forename: Paula
authors.initials: P
authors.lastname: Restrepo
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Bishop
authors.forename: José J
authors.initials: JJ
authors.lastname: Perez
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
authors.forename: Dana B
authors.initials: DB
authors.lastname: Barr
mesh_terms: D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007554:Isotopes; D010636:Phenols / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007554:Isotopes; D010636:Phenols