Optimizing analytical precision in the identification of synthetic cathinones and isomers: a comparative assessment of diverse GC–MS operating parameters

Analyzing new psychoactive substances (NPSs) in forensic laboratories present a formidable challenge globally. Within illicit drug analysis, gas chromatography–mass spectrometry (GC–MS) emerges as a robust analytical tool. This study endeavors to assess and compare peak resolution in the analysis of illicit drugs, specifically focusing on 21 synthetic cathinones, encompassing 9 cathinone isomers. Varied GC–MS operating conditions, including distinct GC–MS columns and thermal gradients, were systematically employed for the simultaneous analysis of these synthetic cathinones. The study utilized HP-1 nonpolar and HP-5MS low-bleed columns to achieve optimal analyte resolution through modulation of GC–MS oven conditions. Mass spectra were meticulously recorded within a mass-to-charge (m/z) range spanning from 40 to 500 in full scan mode. The data showed that the cathinone isomers slightly differed in retention times and mass spectra. The GC oven conditions affected the peak resolution for chromatographic separation even with the same column. The peak resolution improved using a slower thermal gradient heat speed with a prolonged analysis time. Conclusively, the interplay of GC columns and thermal gradients emerged as pivotal factors impacting peak resolution in the analysis of illicit drugs. These empirical insights contribute to a nuanced understanding of peak resolution dynamics and facilitate the identification of synthetic cathinones, including their isomers, in seized materials through the judicious application of GC–MS methodologies.

Graphical abstract