Routine analysis of amphetamine class drugs as their naphthaquinone derivatives in human urine by high-performance liquid chromatography

We describe a simple HPLC method which is suitable for the routine confirma tion of immunoassay positive amphetamine urine samples. The precolumn deriv isation method employing sodium naphthaquinone-4-sulphonate was found to ha ve adequate sensitivity, selectivity and precision for the measurement of a mphetamine, methampheramine, 3,4-methyl enedioxymethamphetamine (MDMA), 3,4 -methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (M DEA) at 500 mu g/l cutoff level for confirmatory analysis of amphetamines i n urine. The specificity of the method is enhanced by detecting the peaks a t two different wavelengths. The ratios of the peak heights measured at the two wavelengths were different for each of the 5 amphetamines analysed. Th ere was no interference from other phenylethylamine analogues that are comm only found in "over the counter" preparations. The HPLC method is compared to a commercial TLC system for detecting amphetamines in urine of drug abus ers attending drug rehabilitation programmes. The HPLC confirmatory method described is a viable alternative to GC or to the more complex and costly G C-MS techniques for confirming amphetamine, methamphetamine, MDMA, MDA and MDEA in urine of drug abusers especially when used in a clinical care setti ng (C) 1999 Elsevier Science B.V. All rights reserved.