title: Development and application of a robust speciation method for determination of six arsenic compounds present in human urine.
abstract: Six arsenic species [arsenate, arsenite, arsenocholine, arsenobetaine, monomethyl arsonic acid, and dimethyl arsinic acid] present in human urine were determined using ion-exchange chromatography combined with inductively coupled plasma mass spectrometry (IC-ICP-MS). Baseline separation was achieved for all six species as well as for the internal standard (potassium hexahydroxy antimonate V) in a single chromatographic run of less than 30 min, using an ammonium carbonate buffer gradient (between 10 and 50 mM) at ambient temperature, in conjunction with cation- and anion-exchange columns in series. The performance of the method was evaluated with respect to linearity, precision, accuracy, and detection limits. This method was applied to determine the concentration of these six arsenic species in human urine samples (n = 251) collected from a population-based exposure assessment survey. Method precision was demonstrated by the analysis of duplicate samples that were prepared over a 2-year analysis period. Total arsenic was also determined for the urine samples using flow injection analysis coupled to ICP-MS. The summed concentration of the arsenic species was compared with the measured arsenic total to demonstrate mass balance.
authors.affiliation: Research Triangle Institute, Research Triangle Park, North Carolina 27709-2194, USA. lmilstein@rti.org
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Milstein
authors.forename: Amal
authors.initials: A
authors.lastname: Essader
authors.forename: Edo D
authors.initials: ED
authors.lastname: Pellizzari
authors.forename: Reshan A
authors.initials: RA
authors.lastname: Fernando
authors.forename: James H
authors.initials: JH
authors.lastname: Raymer
authors.forename: Keith E
authors.initials: KE
authors.lastname: Levine
authors.forename: Olujide
authors.initials: O
authors.lastname: Akinbo
mesh_terms: D001151:Arsenic / Q000737:chemistry* / Q000652:urine*; D002138:Calibration; D002852:Chromatography, Ion Exchange / Q000379:methods; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D013696:Temperature
chemical_list: D001151:Arsenic