Fading spectrophotometric method for the determination of Benzbromarone with Cresol Red

In pH 9.00 tris-HCl buffer medium, Cresol Red reacted with Benzbromarone to form an ion association complex, which causes the fading of the Cresol Red solution.The results showed that the maximum fading wavelength is located at 569.0nm. The concentration of BM obeyed the Beer´s law in the range of 0.09874~22.22μg·mL^-1 and the regression equation was ΔA=0.0972c-0.0245 (c=μg/mL) with the correlation coefficient was 0.9997, the apparent molar absorptivity was 3.978×10⁴ L·mol^-1·cm^-1. Fading spectrophotometric method has been developed for the determination of medicinal preparation and biological samples with Benzbromarone. The recovery of sample was within the the range of 96.31~99.11%.