A SIMPLE HPLC METHOD FOR THE SEPARATION OF AMPHETAMINE ISOMERS IN URINE AND ITS APPLICATION IN DIFFERENTIATING BETWEEN STREET AMPHETAMINE AND PRESCRIBED D-AMPHETAMINE

D-amphetamine has been increasingly prescribed to treat amphetamine ab users. Prescribing D-amphetamine requires laboratory evidence or confi rmation of current use of 'street' amphetamine, using a method which s hould be capable of differentiating between 'street' amphetamine and p rescribed D-amphetamine. We have developed a simple high-performance l iquid chromagraphy (HPLC) method for the separation of the two isomers of amphetamine in urine and have assessed its use in differentiating between 'street' amphetamine and prescribed D-amphetamine. The method is reproducible, free from interference and has a detection limit of 0 .1 mu g/mL for each isomer. Urine from patients prescribed D-amphetami ne contained only a trace amount of L-amphetamine (less than 4%) where as urine from those taking 'street' amphetamine contained more than 50 % L-amphetamine. The method is applicable to confirmation of 'street' amphetamine misuse and for monitoring patient compliance with treatmen t, The presence of 4% or less L-amphetamine in urine would suggest tha t the patient is only taking prescribed D-amphetamine whereas the pres ence of L-amphetamine in higher concentrations suggests that the patie nt is taking 'street' amphetamine, with or without prescribed D-amphet amine.