Highly sensitive determination of trace antimony in water samples by cobalt ion enhanced photochemical vapor generation coupled with atomic fluorescence spectrometry or ICP-MS

Abstract

A method for highly sensitive determination of trace antimony was proposed by using cobalt ion enhanced photochemical vapor generation (PCVG) for sample introduction into atomic fluorescence spectrometry (AFS) or inductively coupled plasma-mass spectrometry (ICP-MS) for elemental detection. During the PCVG process, the sample introduction efficiency of Sb could be significantly improved by addition of 5 mg L−1 Co2+ in the mixed acid medium of 10% (v/v) formic acid and 20% (v/v) acetic acid, with a final 12-fold and 133-fold enhancement of AFS and ICP-MS intensity, respectively. The experimental conditions including enhancement ions, acid medium, UV irradiation, working gas as well as potential interference were investigated in detail. Under the optimal experimental conditions, the limit of detection (LOD) for Sb was 0.05 and 0.001 μg L−1 by using AFS and ICP-MS determination, respectively. The method was successfully used for analysis of real water samples, with satisfactory recoveries of 92–94%.