Monitoring of Levamisole Concentration in Serum of Traffic Participants after Cocaine Consumption.

Abstract

This study highlights the problem of levamisole-adulterated cocaine in context of active traffic participation. For the purposes of levamisole concentration monitoring in human serum, an analytical method based on LC-MS/MS and solid-phase extraction was applied. A Luna 5μm C18 (2) 100 A, 150mm×2mm column and a mobile phase consisting of A (H2 O/methanol=95/5, v/v) and B (H2 O/methanol=3/97, v/v), both with 10mM ammonium acetate and with 0.1% acetic acid (pH=3.2), were used. The validation experiments demonstrated that the method applied was appropriate for levamisole quantification in human serum. For 23% of levamisole-positive samples, the concentrations exceeded 20ng/mL. Therefore, the interaction of this drug with cocaine has to be considered as important for active traffic participation. As a consequence, monitoring of levamisole concentration in human serum is recommended, as long as it is used as cocaine adulterant.