Simultaneous determination of new thioamphetamine designer drugs in plasma by capillary electrophoresis coupled with mass spectrometry

A simple method for the simultaneous identification and quantification of four 2,5-methylenedioxy
derivatives of 4-thioamphetamine (ALEPH series) in plasma samples was developed. The method
consists of solid-phase extraction (SPE) using a Bond Elut C18 cartridge and capillary electrophoresis
coupled with electrospray ionisation mass spectrometry (CE/ESI-MS). The SPE method used
required only simple steps and provided a clean extract from which identification of each drug
was feasible, even at low concentrations. The method was validated according to international
guidelines. The calibration curves were linear over the concentration range of 50 to 1000 ng/mL for all
drugs with correlation coefficients that exceeded 0.998. The lower limits of detection of the drugs were
23–43 ng/mL. The absolute recoveries for the drugs were 64–92% and 75–96% at concentrations of 100
and 500 ng/mL, respectively. The validation data (precision, accuracy, and recovery) show
the reproducibility and selectivity of the method. This clean and simple method allows the routine
detection of designer drugs such as thioamphetamines which may become a serious problem in the
control of illegal drugs.