FI-Spectrophotometric Determination of Catechol amine Drugs in Pharmaceutical Preparations Via Oxidative Coupling Reaction with 4-amino antipyrine and sodium hydroxide

Abstract

A new Spectrophotometric flow injection method has been established for the determination of Catechol amine drugs (Methyl dopa (I), Adrenaline (II) and Dopamine.HCl (III)). The method is based on the oxidative coupling reaction of Catechol amine drugs with 4-amino antipyrine and sodium hydroxide to form a red-water-soluble stable product, that has a maximum absorbance at 500, 509 and 498 nm for Methyl dopa (I), Adrenaline (II), and Dopamine (III) respectively. Beer's law is obeyed in the range of 5-200, 10-100 and 5-50 μg.ml-1 a limit of detection (signal/noise=3) of 0.75, 0.86 and 0.57 μg.ml-1 for (I), (II) and (III) respectively. The method was applied successfully for the determination of (I), (II) and (III) in pharmaceutical preparation with a good precision and accuracy.