Drug screening by using the Toxtyper™ LC-ion trap MS: Optimization of its application on serum samples in a DUID context

The toxicological approach for monitoring Driving Under Influence of Drugs (DUID) requires analytical techniques with a broad spectrum of identification coupled to a high analytical sensitivity. In this context immunological methods are generally used, while GC or LC-MS are applied for the confirmation step. A different approach for drug screening is represented by the Toxtyper™ instrumentation, an LC-MS platform equipped with a high-speed ion trap mass analyzer, provided with ready-to-use protocols and a database of as many as 4500 therapeutic, toxic/illicit drugs and metabolites. The aim of the present work was to verify its performances in real conditions of drug screening of human serum in the context of DUID. To test and compare its analytical performances, four pooled serum samples were fortified with a selected panel of 47 drugs and metabolites. The agreement between the results from the ToxtyperTM and from the confirmatory techniques currently in use at the University of Verona (GC and LC-MS) was investigated by analyzing 90 real samples chosen from those routinely analyzed. The present study highlights the suitability of the ToxtyperTM for drug screening in serum with a sensitivity compatible with the needs of the DUID for all the tested compounds, with the only exception of cannabinoids.