Qualitative Confirmation of 94 New Psychoactive Substances and Metabolites in Urine Using Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry

Abstract

Numerous methods and techniques have been published for the identification of new psychoactive substances (NPS) and their metabolites in urine. However, there lacks a holistic approach to analyze different groups of NPS and their metabolites with decision points for reporting their use. In this study, data-dependent acquisition workflow using liquid chromatography--quadrupole time-of-flight mass spectrometry was developed and validated for the identification of a total of 94 NPS and metabolites in urine using the established decision points. The limit of identification for all analytes was determined at 25% below their respective decision points. The method was demonstrated to be accurate and precise at their respective decision points with extraction recoveries and ion suppression/enhancement ranging from 51.0% to 103.5% and -81.6% to 159.1%, respectively. There was no observed carryover up to 200 ng/mL for all analytes and no interferences from urine matrixes, internal standards and other common drugs of abuse. The extracted drug analytes were stable at 4 and 15°C for up to 3 days. The validated method was successfully evaluated and applied in the testing of urine samples from NPS users. In conclusion, this validated method can analyze a wide range of NPS and their metabolites with the use of decision points for consistency in reporting.