p-Aminobenzoic Acid as a New Reagent in Spectrophotometric Determination of Salbutamol Sulphate Via Oxidative Coupling Reaction

A simple spectrophotmetic method for the determination of salbutamol sulphate (SBS) in aqueous solution has been suggested. The method is based on the oxidative coupling reaction of SBS with p-aminobenzoic acid (PABA) in an alkaline medium (pH=11.96) in presence of N-chlorosuccinimide (NCS) as oxidizing agent to produce an intense blue colored, water soluble and stable product, which showed maximum absorption at 622 nm. Beers law is obeyed over the range2.0 - 25.0 g. ml-1 of SBS and limit of detection (LOD) of 0.460 g. ml-1, limit of quantitation (LOQ) of 1.536 g. ml-1, a molar absorptivity of 1.828104 l. mol-1. cm-1. and Sandells sensitivity index of 0.0315 g. cm-2. The method has been successfully applied to the determination of SBS in pharmaceutical preparations.