Cloud point extraction spectrophotometric determination of trace quantities of bismuth in urine

A cloud point extraction process using the nonionic surfactant Triton X-114 to extract bismuth from aqueous solutions was investigated. The method is based on the complexation reaction of Bi(III) with bromopyrogallol red (BPR) and micelle-mediated extraction of the complex. The optimal extraction and reaction conditions (e.g., pH, reagent concentration, effect of time) were studied, and the analytical characteristics of the method (e.g., limit of detection, linear range) were obtained. Linearity was obeyed in the range of 4.60-120.0 ng mL(-1) of Bi(III) ion. The detection limit of the method was 2.0 ng mL(-1) of Bi(III) ion. The interference effect of some anions and cations was also tested. The method was applied to the determination of bismuth in human urine sample.