AMPHETAMINE AND METHAMPHETAMINE DETERMINATION IN URINE BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH SODIUM 1,2-NAPHTHOQUINONE 4-SULFONATE AS DERIVATIZING AGENT AND SOLID-PHASE EXTRACTION FOR SAMPLE CLEANUP

A rapid method is described for the identification and determination of amphetamine and methamphetamine in human urine samples by liquid chromatography with UV-Vis detection. The samples were transferred onto a C-18 solid-phase extraction column and chromatographed on a Hypersil ODS RP C-18, 5 mu m (250 x 4 mm I.D.) with an acetonitrile-water elution gradient containing propylamine. Under these conditions, the amines are eluted with a short retention time. The procedure has been applied to the determination of amphetamine and methamphetamine in the range 0.3-4.0 mu g/ml in spiked urine samples. The detection limits at 280 nm were 4 and 2 ng/ml for amphetamine and methamphetamine, respectively. The intra-day and inter-day precision and accuracy of the method were studied.