This report describes the development of a dilute-and-shoot LC-QqQ-MS/MS screening method for urine using dynamic multiple reaction monitoring (dMRM) mode capable of detecting 826 NPS and other licit and illicit analytes.
The presence of novel psychoactive substances (NPS) in forensic casework world-wide has steadily increased over the past decades. NPS pose difficulties for detection, since there are many generations and structural variations circulating in communities and the illicit market at any given time. There are currently no validated screening or quantitation methods available that encompass more than a limited number of NPS. The use of a liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) targeted method allows for the detection of a large number of NPS, mainly due to the high selectivity and sensitivity of this approach; however, a major challenge with developing such a comprehensive method is that full validation can be extremely tedious and time consuming. The work presented in the current article employs a series of non-coeluting NPS standard mixtures to facilitate method validation. The method was fully validated according to accepted guidelines for quantitative analysis of 80 NPS using three non-coeluting standard NPS mixtures. Limits of detection and quantification were in the 0.01–0.36 ng/g range for all analytes. In addition, a qualitative screen capable of identifying all 826 analytes was developed. The quantitative method was successfully applied to a set of blind spiked urine specimens, while the qualitative screen was effective in identifying NPS and other relevant analytes in a series of authentic urine specimens. (publisher abstract modified)