Detection and identification of drugs and toxicants in human body fluids by liquid chromatography–tandem mass spectrometry under data-dependent acquisition control and automated database search

[Display omitted] ► Untargeted LC/MS/MS screening for drug identification in blood, plasma and urine. ► The assay shares the sample preparation workflow with established GC/MS screening. ► Compound identification with the “Wiley Registry of Tandem Mass Spectral Data”. ► Selectivity, detection capability and reliability of identification are discussed. ► Parallel screening with LC/MS/MS and GC/MS offers utmost reliability. Systematic toxicological analysis (STA) is aimed at detecting and identifying all substances of toxicological relevance (i.e. drugs, drugs of abuse, poisons and/or their metabolites) in biological material. Particularly, gas chromatography–mass spectrometry (GC/MS) represents a competent and commonly applied screening and confirmation tool. Herein, we present an untargeted liquid chromatography–tandem mass spectrometry (LC/MS/MS) assay aimed to complement existing GC/MS screening for the detection and identification of drugs in blood, plasma and urine samples. Solid-phase extraction was accomplished on mixed-mode cartridges. LC was based on gradient elution in a miniaturized C18 column. High resolution electrospray ionization-MS/MS in positive ion mode with data-dependent acquisition control was used to generate tandem mass spectral information that enabled compound identification via automated library search in the “Wiley Registry of Tandem Mass Spectral Data, MSforID”. Fitness of the developed LC/MS/MS method for application in STA in terms of selectivity, detection capability and reliability of identification (sensitivity/specificity) was demonstrated with blank samples, certified reference materials, proficiency test samples, and authentic casework samples.