Chemical vapor generation of bismuth in non-aqueous phase based on cloud point extraction coupled with thermospray flame furnace atomic absorption spectrometric determination

Abstract

A novel method for the chemical vapor generation (CVG) of bismuth in non-aqueous phase based on cloud point extraction (CPE) coupled with thermospray flame furnace atomic absorption spectrometric (TS-FF-AAS) determination was developed. The method is based on the complex of bismuth with ammonium pyrrolidine dithiocarbamate (APDC). When the temperature of the system was higher than the cloud point of Triton X-100, Bi-APDC complex was extracted into Triton X-100 and separation of the analyte from the matrix was achieved. Volatile species of Bi were effectively generated through reduction of the extraction organic phase with solid KBH4 in non-aqueous phase. Some parameters that influenced CVG, extraction and subsequent determination were evaluated in detail, such as the concentrations of Triton X-100 and APDC, pH and extraction time, flow rates of carrier gas, as well as interferences. Under optimized conditions, the detection limit (LOD) for Bi was 8ngmL−1. Relative standard deviation for five replicate determinations of the standard solution containing 200ngmL−1 Bi was 3.8%. The proposed method was successfully applied to the determination of Bi in natural water samples, ore samples and certified reference materials with satisfactory results.