Abstract

New, simple and sensitive specteophotometric method has been developed for the determination of sulfamerazine. The method is based on the diazitization coupling reaction of sulfamerazine with resorcinol in alkaline medium were studied. The reaction gave an intense water soluble yellow product that has a maximum absorption at 422 nm and Ԑmax of 2.97 × 104 L.mole-1.cm-1. A linear correlation (1-8μg per 25ml 0.4 – 3.2 ppm) was found between absorbance at λmax and concentration. The results obtained are both precise (RSD was better than 0.8) and accurate (relative error was better than – 0.11). The coloured product was found to be 1:1 sulfamerazine: resorcinol. The stability constant and the rate constant of reaction under optimized conditions at room temperature were 0.25 x105 L.mole-1 and 2.25x10-2 min-1 . The proposed method was successfully applied to the determination of sulfamerazine in synthetic samples of pharmaceutical formulation. Keywords: Diazotization coupling reaction, Sulfamerazine, Resorcinol, Spectrophotometric determination. I