Spectrophotometric Determination of Sulphadiazine in Pharmaceutical Preparations Via Arsenazo III - Cerium (III) Reaction

A simple, rapid, accurate and precise spectrophotometric method is proposed for determining sulphadiazine (SDA) in pure from and in its pharmaceutical and veterinary preparations. The method is based on oxidation-reduction reaction between SDA and cerium(IV) ion (ceric ion), then the subsequent reaction of cerium(III) with arsenazo III reagent in acidic medium to produce a green-blue complex which is stable, water soluble and has a maximum absorption at 654 nm with a molar absorptivity of 1.22*10^5 l.mol^-1. cm^-1. beer's law is obeyed in the concntration range from 1 to 10mg SDA in a final volume of 25 ml. The proposed method has been applied successfully to determine SDA in pharmaceutical and veterinary preparations.