Determination of ( S)(−)-cathinone by spectrophotometric detection

Abstract

Previous studies on the Khat plant ( Catha edulis, Celastraceae) illustrated the importance of using freshly harvested young shoots and leaves such that cathinone, the principle active component and Schedule I controlled drug contained within the plant, could be suitably isolated and identified. The purpose of this work was to develop a quantitative analytical technique for the determination of cathinone. The proposed method is based on treating the reductant cathinone with copper(II)–neocuproine reagent in sodium acetate-buffered medium followed by measuring the absorbance of the copper(I)–neocuproine complex at 455 nm. The calibration plot is linear in the range 0.08–25 μg ml −1 with a detection limit of 0.08 μg ml −1. The precision of the method, expressed as the relative standard deviation, is 1.35% for 10 μg ml −1 cathinone. Good recoveries have been obtained in applying the method to the analysis of cathinone in Khat leaves.