title: Simultaneous speciation analysis of Sb(III), Sb(V) and (CH3)3SbCl2 by high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry detection (HPLC-HG-AFS): application to antimony speciation in sea water.
abstract: This paper presents an improvement for the simultaneous separation of Sb(V), Sb(III) and (CH3)3SbCl2 species by high performance liquid chromatography (HPLC) and its detection by hydride generation-atomic fluorescence spectrometry (HG-AFS). The separation was performed on an anion exchange column PRP-X100 using a gradient elution program between EDTA/KHP (potasium hydrogen phtalate) as first mobile phase and phosphate solutions solution as the second one. The chromatographic separation and the HG-AFS parameters were optimized by experimental design. The best results were obtained by using an elution program with 20 mmol l(-1) EDTA + 2 mmol(-01) KHP solution at pH 4.5, during 1.15 min, then change to 50 mmol l(-1) (NH4)2HPO4 solution at pH 8.3, switching back after 4.0 min to the first mobile phase, until 5 min, with a constant flow rate of 1.5 ml min(-1). Retention time of Sb(V), Sb(III) and trimethylantimony species were 1.22, 2.31 and 3.45 min and the detection limits were 0.13; 0.07 and 0.13 microg l(-1), respectively. Studies on the stability of this antimony species in sea water samples on the function of the elapsed time of storage in refrigerator at 4 degrees C was performed employing the optimized method. Results revealed that Sb(III) is easily oxidized within some hours to Sb(V) in sea water stored at 4 degrees C. However, when the sea water was immediately mixed with EDTA no oxidation of Sb(III) was observed up to 1 week of storage. The proposed methodology was then applied to the antimony speciation in sea water samples.
authors.affiliation: Laboratorio de Química Analítica y Ambiental, Instituto de Química, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, P.O. Box 4059, Valparaíso, Chile. idegrego@ucv.cl
authors.forename: Ida
authors.initials: I
authors.lastname: De Gregori
authors.forename: Waldo
authors.initials: W
authors.lastname: Quiroz
authors.forename: Hugo
authors.initials: H
authors.lastname: Pinochet
authors.forename: Florence
authors.initials: F
authors.lastname: Pannier
authors.forename: Martine
authors.initials: M
authors.lastname: Potin-Gautier
mesh_terms: D000704:Analysis of Variance; D000965:Antimony / Q000032:analysis* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D009942:Organometallic Compounds; C113588:trimethylantimony; D000965:Antimony