Fast screening of 88 pharmaceutical drugs and metabolites in whole blood by ultra-high performance liquid chromatography - tandem mass spectrometry

Forensic investigations involving acute or lethal intoxication, drug facilitated sexual assault, driving or workplace impairment, frequently require the analysis of fresh or post-mortem blood samples to check out a wide variety of pharmaceutical and illicit drugs, even after single dose consumption. A sensitive and selective UHPLC-MS/MS screening method was developed for fast screening of 88 psychoactive drugs and metabolites in blood samples, including the ones most frequently involved in acute intoxications and forensic investigations in Italy. The new method allows short sample processing and analysis time (the whole procedure can be accomplished in less than 30 min) together with the simultaneous monitoring of a large number of pharmaceutical substances. These features represent crucial factors in the aproach of acute intoxications, when the patient requires urgent and appropriate therapy. Blood sample treatment was limited to protein precipitation. Two UHPLC-MS/MS runs in positive and negative electrospray ionization modes were performed. The data were acquired at unit mass resolution in the selected reaction monitoring (SRM) mode. According to international guidelines, linearity range, precision, trueness, detection and quantification limits (LODs and LOQs), recovery, selectivity, specificity, carry-over and matrix effect phenomena were determined. Despite the limited sample purification and the inherent decreased chance of eliminating any potential interference, the present multiresidue screening method proved extremely effective and sensitive, allowing the detection of all tested drugs, even belonging to structurally different classes of substances. Moreover, the developed method is easily susceptible of further expansion to encompass more drugs, either new or becoming important for criminal investigation. This protocol was also applied to the analysis of authentic blood samples collected from victims of various crimes in routine casework, whose relevance in forensic investigations is presented in five cases.