Matrix Solid-Phase Dispersion for the HPLC–DAD Determination of Psychoactive Phenylpropylamino Alkaloids from Khat (Catha edulis Forsk) Chewing Leaves

A fast and simple procedure based on matrix solid-phase dispersion was developed for the extraction of psychoactive phenylpropylamino alkaloids; cathinone, cathine and norephedrine, from khat (Catha edulis Forsk) chewing leaves, a stimulant and drug of abuse plant. Determination of the alkaloids was carried out by high performance liquid chromatography with diode array detection. Several extraction parameters, such as type of dispersant, type and volume of elution solvent and the ratio of sample to sorbent material were evaluated and optimized. Mean recoveries ranging from 89 to 92 % with relative SD of less than 6 % were obtained. A marked diversity in the phenylpropylamino alkaloid content and composition was found in seventeen different cultivars of Ethiopian khat. ANOVA results showed the existence of significant differences between the alkaloids profiles among samples of different varieties from different geographical locations in Ethiopia. The proposed method is simpler, faster and comparably more efficient than the frequently reported maceration followed by liquid–liquid extraction but as good and efficient as ultrasonic assisted extraction followed by solid-phase extraction.