title: Determination of cobalt in urine by FI-ICP-AES with online preconcentration.
abstract: A method for the preconcentration and determination of cobalt in human urine samples was developed. The online preconcentration and determination were attained using inductively coupled plasma atomic emission spectromety (ICP-AES) coupled to a flow injection (FI) method. Cobalt was retained on an Amberlite XAD-7 resin as cobalt-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex at pH 9.5. Cobalt was removed from the microcolumn with perchloric acid. A sensitivity enhancement factor of 90 was obtained with respect to cobalt determination by ICP-AES without preconcentration. The value of detection limit for the preconcentration method proposed was 25 ng/L. The precision for 10 replicate determinations at the 5 mg/L (mean +/- SD, 5.1 +/- 0.14) Co level was 2.7% relative standard deviation, calculated from the peak heights obtained. The calibration graph preconcentration method for cobalt was linear with a correlation coefficient of 0.9994 from approximately 0.25 mg/L up to at least 100 mg/L. The method was successfully applied to the determination of cobalt in human urine samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, Argentina.
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Farias
authors.forename: Rodolfo G
authors.initials: RG
authors.lastname: Wuilloud
authors.forename: Susana
authors.initials: S
authors.lastname: Moyano
authors.forename: José A
authors.initials: JA
authors.lastname: Gásquez
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Olsina
authors.forename: Luis D
authors.initials: LD
authors.lastname: Martinez
mesh_terms: D002138:Calibration; D003035:Cobalt / Q000652:urine*; D006801:Humans; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D003035:Cobalt