Determination of illicit drugs and related substances by high-performance liquid chromatography with an electrochemical coulometric-array detector

A general method for the simultaneous determination of fifteen common drugs (6-acetylmorphine, 3,4-methylenedioxymetamphetamine, buprenorphin, cocaine, codeine, dihydrocodeine, ethylmorphine, heroin, hydrocodone, lidocaine, methadone, morphine, naloxone, procaine and thebaine) was developed using reversed-phase HPLC and electrochemical detection. The separation of the drugs was achieved by using as the mobile phase 20 mM monobasic sodium phosphate-acetonitrile (90:10) with a gradient to 50% of the organic modifier, on a silica based C-18 column (150 x 4.6 mm I.D.) of 3 mu m particle size and by the selectivity supplied by an array of eight coulometric electrodes at increasing potential. It was possible to identify and to determine fifteen different drugs in the same chromatographic run in 50 min. The method was tentatively applied to the determination of drugs in extracts of human hair.