Spectrophotometric Method for Determination of Primaquine in Pharmaceutical Formulations via Derivatization with 1,2-Naphthoquinone-4-Sulfonate

A rapid, simple and sensitive method for the determination of primaquine (PQ) using sodium 1,2-naphthoquinone-4-sulfonate (NQS) has been developed. The method is based on the formation of a brown color adduct from the reaction between PQ and NQS. The nucleophilic substitution reaction proceeds quantitatively at pH 10 buffer solution with absorption maximum at 485 nm. The calibration curve is linear over the range 10-60μg/mL and describes by the regression equation A? 0.005X+ 0.055C with a regression coefficient 0.9998. The limit of detection and quantity are 3.2 μg/mL and 9.9 μg/ mL respectively. The method is simple and can be applied for determination of PQ in pharmaceutical formulation in quality control laboratories.