RP-FI-Inhibitory Photometric Determination of Bismuth(Ⅲ) in Drugs

It was found that in H3BO3-KCl-NaOH buffer medium of pH 7.8, the oxidative color-fading of crystal violet (CV) by H2O2 was inhibited by the presence of Bi(Ⅲ). Based on these facts, the determination of Bi(Ⅲ) by reverse phase flow injection inhibitory photometry was proposed. Linear relationship between values of ΔA and mass concentration of Bi(Ⅲ) was obtained in the range of 0.005-0.05 mg·L-1 when measured at the absorption maximum of 590 nm. Detection limit (3S/N) of the method found was 7.28×10-4mg·L-1. The proposed method was used in the determination of Bi(Ⅲ) in gastric drug, and values of recovery and RSD (n=11) found were 101.5% and 0.079% respectively.