Multianalyte Approach-Including Automated Preparation of Calibrators-for Validated Quantification of 82 Drugs in Whole Blood by Liquid Chromatography-Tandem Mass Spectrometry.

Abstract

Bioanalysis, such as the quantification of drugs in different matrices, is of great importance in forensic toxicology. Nowadays, mainly so-called multianalyte approaches are used given their increased speed and effectiveness. However, such multianalyte procedures can be difficult to develop and maintain with sufficient robustness in the laboratory. One aspect of this is the tedious, manual preparation of spiking solutions containing such a great number of analytes. Therefore, the current study aimed to develop and validate a fast, simple, and robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of 82 classic drugs and to evaluate an alternative autosampler-assisted automated approach for the preparation of spiking solutions. Simple protein precipitation of 200-μL whole blood was used followed by analysis by reversed-phase LC-MS/MS in advanced scheduled multiple reaction monitoring (MRM) mode. The method was fully validated according to international guidelines, including selectivity, recovery, matrix effects, linearity, bias/imprecision, processed-sample stability, and limits. Validation criteria were fulfilled for all analytes except for buprenorphine and five benzodiazepines. In the context of a multianalyte procedure, a (multipurpose) autosampler-assisted automatic preparation of calibrator spiking solutions proved comparable to manual preparation. Thus, automated preparation can overcome the frequently performed manual, time-consuming, and error-prone steps of multianalyte approaches and still allow for customized calibration ranges. Since its introduction, more than 8000 cases have been measured with the presented method, and 35 proficiency tests have been passed.