Emergency toxicology analysis – Method development for the straightforward determination of total 70 drugs and metabolites in human blood plasma by LC-MSn

Abstract

Quantification of 70 emergency toxicology (ET) relevant analytes in human blood plasma using the Bruker Daltonik Toxtyper (TT) system. Rapid and comprehensive qualitative and quantitative methods are crucial in 24/7 ET to support the diagnosis and treatment of acute intoxications. This includes estimating their course and monitoring the effectiveness of possible detoxification. The aim of this study was the simultaneous qualitative and quantitative analysis of 64 drugs and six of their metabolites in human blood plasma by liquid chromatography-ion trap mass spectrometry (LC-MSn, Bruker Daltonik TT). Analytes included compound classes often requested in ET such as analgesics, anticonvulsants, antidepressants, antidiabetics, antiemetics, antihistamines, antihypertensives, benzodiazepines, or neuroleptics. A standard liquid-liquid extraction procedure was used for sample preparation followed by 1:5 dilution of the final extract (Caspar AC. Drug Test Anal 2019;11:102–111). Analyzes were performed using the TT system consisting of a Bruker amazon speed ion trap and a Thermo Fisher Dionex Ultimate 3000 LC system. Plasma concentrations were determined using an electronically stored five-point calibration. Validation was performed according to the European Medicines Agency (EMA) guideline on bioanalytical method validation and the recommendations of the Society of Toxicological and Forensic Chemistry (GTFCh) for ET quantification including selectivity, carry-over, accuracy, precision, and matrix effects. Finally, applicability was tested using 197 patient samples containing 37 different drugs and 5 of their metabolites. The method was selective for all analytes and no relevant carry-over and matrix effect could be observed. A linear and weighted calibration model could be used for all tested analytes. Accuracy and precision recommended for ET could be fulfilled for all tested analytes, except for aripiprazole, diphenhydramine, ketamine, melperone, norpethidine, nortilidine, olanzapine, metformin, pethidine, sertraline, and tilidine. The results after analysis of patient plasma were compared to those obtained by reference LC-tandem MS or gas chromatography-MS methods and data corresponded in case of 190 samples. The concentration levels in the remaining seven samples did not correspond to those determined by one of the reference methods. The present method provides a fast, robust, and reliable blood plasma screening for 70 analytes and an additional quantification of 59 analytes relevant in ET. Due to an electronically stored five-point calibration and a simple “push and print solution”, blood plasma levels of the analytes could be assessed straightforward. Furthermore, the applicability of the method by analyzing ET cases could be demonstrated.