Screening determination of four amphetamine-type drugs in street-grade illegal tablets and urine samples by portable capillary electrophoresis with contactless conductivity detection

A simple and inexpensive method for the identification of four substituted amphetamines, namely, 3,4-methylenedioxy methamphetamine (MDMA), methamphetamine (MA), 3,4-methylenedioxy amphetamine (MDA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) was developed using an in-house constructed semi-automated portable capillary electrophoresis instrument (CE) with capacitively coupled contactless conductivity detection ((CD)-D-4). Arginine 10 mM adjusted to pH 45 with acetic acid was found to be the optimal background electrolyte for the CE-(CD)-D-4 determination of these compounds. The best detection limits achieved with and without a sample preconcentration process were 10 ppb and 500 ppb, respectively. Substituted amphetamines were found in different seized illicit club drug tablets and urine samples collected from different suspected users. Good agreement between results from CE-(CD)-D-4 and those with the confirmation method (GC-MS) was achieved, with correlation coefficients for the two pairs of data of more than 0.99. (C) 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.