title: Analytical performance of accelerator mass spectrometry and liquid scintillation counting for detection of 14C-labeled atrazine metabolites in human urine.
abstract: Accelerator mass spectrometry (AMS) has been applied to the detection of 14C-labeled urinary metabolites of the triazine herbicide, atrazine, and the analytical performance of AMS has been directly compared to that of liquid scintillation counting (LSC). Ten human subjects were given a dermal dose of 14C-labeled atrazine over 24 h, and urine from the subjects was collected over a 7-day period. Concentrations of 14C in the samples have been determined by AMS and LSC and range from 1.8 fmol/mL to 4.3 pmol/mL. Data from these two methods have a correlation coefficient of 0.998 for a linear plot of the entire sample set. Accelerator mass spectrometry provides superior concentration (2.2 vs 27 fmol/mL) and mass (5.5 vs 54,000 amol) detection limits relative to those of LSC for these samples. The precision of the data provided by AMS for low-level samples is 1.7%, and the day-to-day reproducibility of the AMS measurements is 3.9%. Factors limiting AMS detection limits for these samples and ways in which these can be improved are examined.
authors.affiliation: Department of Entomology, University of California, Davis 95616, USA. sdgilman@utk.edu
authors.forename: S D
authors.initials: SD
authors.lastname: Gilman
authors.forename: S J
authors.initials: SJ
authors.lastname: Gee
authors.forename: B D
authors.initials: BD
authors.lastname: Hammock
authors.forename: J S
authors.initials: JS
authors.lastname: Vogel
authors.forename: K
authors.initials: K
authors.lastname: Haack
authors.forename: B A
authors.initials: BA
authors.lastname: Buchholz
authors.forename: S P
authors.initials: SP
authors.lastname: Freeman
authors.forename: R C
authors.initials: RC
authors.lastname: Wester
authors.forename: X
authors.initials: X
authors.lastname: Hui
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000328:Adult; D000368:Aged; D001280:Atrazine / Q000652:urine*; D002250:Carbon Radioisotopes; D005260:Female; D006540:Herbicides / Q000652:urine*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D012588:Scintillation Counting / Q000379:methods
chemical_list: D002250:Carbon Radioisotopes; D006540:Herbicides; D001280:Atrazine