RESUMEN
A screening method for 70 psychoactive drugs or drug metabolites in human serum by solid-phase extraction with subsequent high-performance liquid chromatography and electrospray ionization mass spectrometry was developed. Enhanced selectivity of detection was obtained by collision-induced dissociation using two different skimmer voltages for the individual scan. The mass spectra and the retention times of the compounds were incorporated into a self-generated spectra library for identification in screening experiments. The detection limits were found to be between 0.1 and 5 ng/mL serum for the majority of the compounds when measured in the selected ion mode. Because of the very small serum concentrations and the rather low extraction yield, lysergide could not be detected in this way. It was demonstrated with 140 serum samples from alcohol-related traffic cases that this method is suitable for a routine screening in a forensic laboratory.