Microsampling and enantioselective liquid chromatography coupled to mass spectrometry for chiral bioanalysis of novel psychoactive substances br

m this paper, the dev'cpment of efficient enanticsetective S1PLC methois for the dnalysis of Rile nenaon iota ran substituted phenethylamines, two sukstituted tryptan >> nes, and three suustituted cath:nones is described. For the first time, reversed phase (eluents made up ..ith acidic water methanol snlutions) and polar-ionic (eluent made up with an acetoniuile methanol solution incmporatinj both an acidic and a basic additive;i conditions fully compatible with mass specunmen-y (MS) detectors were applied with a chiral stationary phase (CEP) incmporating the (+)-(18-crovm-6)-tetracarboxylic acid chiral selector. Enantioresolution was achieved for nine cornpounds with a and R5 factors up to 1.32 and 5.12, respectively. Circular diclunism (CD) detection, CD spectroscopy in stopped-flow mode and quantdm mechanical (QM) calculations were successfidly employed to investigate the absolute stereochemisny of mephedrone, methylone and butylone and allowed to establish a (R)<(S) enantiomeric elution order for these compounds on the chosen CSP. Whole blood miniaturized samples collected by means of volurnetric absorptive microsampling (VAMS) technoloy and fortified with the target analytes were extracted following an optirnized protocol and effectively analysed by means of an ultra-high performance liquid chrornatography-MS system. By this way a proof-ofconcept procedtun was applied, demonstrating the suitability of the method for quali-quantitative enantioselective assessment of the selected psychoactive substances in advanced biological microsamples. VAMS microsamplers including a polypropylene handle topped with a small tip of a polymeric porous material were used and allowed to voltunetrically collect small aliquots of whole blood (10 gL) independently from its density. Highly appreciable volumetric acctuacy (bias, in the -8.7-8.1% range) and precision (% CV, in the 2.8-5.9% range) noned out.

Automated summary

This paper describes the development of efficient enantioselective S1PLC methods for the analysis of various substituted phenethylamines, tryptamines, and cathinones. Reversed phase and polar-ionic conditions were applied with a chiral stationary phase incorporating a specific chiral selector. Enantioresolution was achieved for nine compounds with high separation factors. The absolute stereochemistry of certain compounds was investigated using different detection and spectroscopic techniques. The suitability of the method for analyzing psychoactive substances in small biological samples was also demonstrated.