SIMULTANEOUS DETERMINATION OF THREE STUPEFACIENTS IN FOODSTUFF USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A high-performance liquid chromatography (HPLC) method with photodiode array detection (PDA) was developed for the determination of three commonly used stupefacients, lidocaine, diazepam, and ketamine, in foodstuff and drinks used for cheating or deceiving a person. The method involves extraction of the selected drugs using ethanol at room temperature. Using the optimum mobile phase of acetonitrile-water (40:60, v/v, pH 3.0, 0.01M sodium dihydrogen phosphate) and a flow rate of 1.0mL/min, the separation was achieved on a PrincetonSPHER-100 C18 (250mmx4.6mm, 5 mu m particle size) column and UV detection at 252nm. The limit of detection achieved was 0.025 mu g/mL, 0.1 mu g/mL, and 0.1 mu g/mL for lidocaine, diazepam, and ketamine, respectively. The developed method is simple, precise, and sensitive and could be applied successfully for the determination of laced foodstuff.