Spectrophotometric determination of mesalazine via arsenazo III-cerium (III)‎ reaction

Abstract EN

A simple and sensitive spectrophotometric method has been developed for the determination of mesalazine (5-aminosalicylic acid) in pure form and in its pharmaceutical preparation(capsule).

The method is based on the oxidation-reduction reaction between mesalazine and cerium (IV) ion, then 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 2.103×105 l.mol-1.cm -1.

Beer s law is obeyed in the concentration range of 0.5 to 14 μg of mesalazine in a final volume of 25 ml.

The proposed method has been applied successfully for determination of mesalazine in pharmaceutical preparation (capsule).