Use of LC–HRMS in full scan‐XIC mode for multi‐analyte urine drug testing – a step towards a ‘black‐box’ solution?

Abstract

The influx of new psychoactive substances (NPS) has created a need for improved methods for drug testing in toxicology laboratories. The aim of this work was to design, validate and apply a multi-analyte liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method for screening of 148 target analytes belonging to the NPS class, plant alkaloids and new psychoactive therapeutic drugs. The analytical method used a fivefold dilution of urine with nine deuterated internal standards and injection of 2 μl. The LC system involved a 2.0 μm 100 × 2.0 mm YMC-UltraHT Hydrosphere-C column and gradient elution with a flow rate of 0.5 ml/min and a total analysis time of 6.0 min. Solvent A consisted of 10 mmol/l ammonium formate and 0.005% formic acid, pH 4.8, and Solvent B was methanol with 10 mmol/l ammonium formate and 0.005% formic acid. The HRMS (Q Exactive, Thermo Scientific) used a heated electrospray interface and was operated in positive mode with 70 000 resolution. The scan range was 100-650 Da, and data for extracted ion chromatograms used ± 10 ppm tolerance. Product ion monitoring was applied for confirmation analysis and for some selected analytes also for screening. Method validation demonstrated limited influence from urine matrix, linear response within the measuring range (typically 0.1-1.0 μg/ml) and acceptable imprecision in quantification (CV <15%). A few analytes were found to be unstable in urine upon storage. The method was successfully applied for routine drug testing of 17 936 unknown samples, of which 2715 (15%) contained 52 of the 148 analytes. It is concluded that the method design based on simple dilution of urine and using LC-HRMS in extracted ion chromatogram mode may offer an analytical system for urine drug testing that fulfils the requirement of a 'black box' solution and can replace immunochemical screening applied on autoanalyzers. Copyright © 2017 John Wiley & Sons, Ltd.

Drug trends and harm related to new psychoactive substances (NPS) in Sweden from 2010 to 2016: Experiences from the STRIDA project

“…Toxicological case series from the STRIDA project highlighting a variety of especially harmful NPS have been published continuously, covering structural variants of phenethylamine and cathinone stimulants [15,[38][39][40][41], hallucinogenic and dissociative drugs [37,47], fentanyl derivatives and other opioids [29,30,33,48,49], SCRA [31], and designer benzodiazepines [34]. There have also been several bioanalytical studies related to recommended strategies for drug testing of NPS [16,17,23,50], and results from the investigation of drug products that were sometimes submitted together with the biological samples [24].…”

“…The biological samples received in the STRIDA project were subjected to a comprehensive toxicological investigation, involving routine immunochemical assays targeting the classical illicit drugs, and multi-component liquid chromatographic-tandem mass spectrometric (LC-MS/ MS) and LC-high-resolution single and tandem MS (LC-HRMS(/MS)) screening and confirmation methods targeting NPS, classical drugs, plant-and mushroom-derived substances, and prescription pharmaceuticals, as detailed elsewhere [8,[21][22][23]. The number of substances covered increased over time, as the LC-HRMS methods were continuously updated when new drugs appeared, and reference materials became available.…”

Detectability of fentanyl and designer fentanyls in urine by 3 commercial fentanyl immunoassays

“…The LC-HRMS method used as the reference method is described in detail elsewhere. 18 In brief, MS analysis was performed in positive electrospray ionization mode using both full scan and MS/MS mode.…”

“…Due to the high turnover of NPS, upto-date commercial immunoassays for this type of drugs are rarely available, requiring direct use of more laborious and expensive MS methods for NPS testing. 18 A limited analytical selectivity (limited specificity) is an inherent drawback of immunoassays, as the antibodies are directed toward a chemical structure (epitope) of the antigen that may be unique for a single substance but is more commonly shared by several compounds with resulting risk for false positives.…”

“…Liquid chromatography (LC) combined with high-resolution MS (LC-HRMS) was used as the reference method. 15,18 2 | EXPERIMENTAL…”