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 micrograms ml-1 with a detection limit of 0.08 microgram ml-1. The precision of the method, expressed as the relative standard deviation, is 1.35% for 10 micrograms ml-1 cathinone. Good recoveries have been obtained in applying the method to the analysis of cathinone in Khat leaves.
Subject(s)
Alkaloids/analysis , Central Nervous System Stimulants/analysis , Psychotropic Drugs/analysis , Buffers , Copper/chemistry , Drug Stability , Phenanthrolines/chemistry , Plant Extracts/analysis , Plant Leaves , Spectrophotometry/methodsABSTRACT
The formation of a red complex between boron and the quinalizarin reagent was investigated and used as the basis for a simple and sensitive spectrophotometric method for boron in date cultivars. At 620 nm, the absorbance was linear (r = 0.999) over the 0.25-2.5 micrograms/mL concentration range. The molar absorptivity was found to be 2.23 x 10(3) mol-1 cm-1 and the relative standard deviation for 10 replicates (1.0 micrograms/mL) was 0.97%.
