Spectrophotometric determination of bismuth in water samples after preconcentration of its thiourea–bromide ternary complex on activated carbon

A simple, accurate, sensitive and reliable method for the selective extraction and spectrophotometric determination of Bi(III) was developed. Bi(III) was collected on activated carbon after complexation with thiourea and bromide ion in acidic media. The complex retained on activated carbon was then desorbed with the bromide solution in N,N-dimethylformamide (DMF) and determined spectrophotometrically at 375 nm. The linear calibration ranges and limit of detection for the proposed method was 1.00×10−9–1.50×10−7 and 8.00×10−10 mol l−1, respectively. The influence of the interfering cations and anions on the determination of bismuth was investigated. The method was successfully applied to the extraction and determination of bismuth in natural water samples.