Development and Evaluation of a Targeted Gas Chromatography Mass Spectrometry (GC-MS) Method for Analysis of Synthetic Cathinones
Edward Sisco, Amber Burns, Arun Moorthy
With the increased prevalence of novel psychoactive substances (NPSs), seized drug analysis has become more complex and challenging due, in part, to changing chemical structures and isomeric species. To assist in addressing these challenges a series of studies are ongoing to develop a suite of targeted gas chromatography mass spectrometry (GC-MS) methods for different classes of seized drugs. This work describes the efforts undertaken to create a method for the analysis of synthetic cathinones. Development of the method involved investigation of range of GC-MS parameters including column stationary phase, temperature program, flow rate, mass spectrometer source temperature and tune type, among others, using a seven-component test solution. The targeted method was then compared to a general method used at the Maryland State Police Forensic Sciences Division to quantify the potential gains. The method produced a two-fold increase in chromatographic separation even with a 3.83 min reduction in runtime (compared to the general method). Using the most sensitive settings the method had an approximate limit of detection five times lower. Once the targeted method was developed, an additional 44 cathinones were analyzed to establish locked retention times and retention indices for a larger suite of cathinones. While the retention times of three pairs of cathinones were not statistically different, all but one pair had mass spectra that were easily distinguishable. Using a more conservative minimum retention time difference of 2 % revealed one additional pair of compounds that could not be easily distinguished by mass spectra. Finally, ten case samples were analyzed using the targeted method to ensure suitability for casework and adjust the sensitivity to a desired level. Development of the targeted GC-MS methods, like the one described here, are part of a larger effort to create a workflow tailored to address the challenges of modern drug chemistry.
, Burns, A.
and Moorthy, A.
Development and Evaluation of a Targeted Gas Chromatography Mass Spectrometry (GC-MS) Method for Analysis of Synthetic Cathinones, Journal of Forensic Sciences, [online], https://doi.org/10.1111/1556-4029.14789, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931874
(Accessed January 16, 2022)