Ultrafast capillary electrophoresis/mass spectrometry of controlled substances with optical isomer separation in about a minute

Abstract

Analysis of forensic evidence by information-rich technologies such as mass spectrometry (MS) is one of the fastest growing areas in forensic analysis. To provide more accurate identification of forensic evidence, in the past few years there has been a growing interest in moving this technology to the field for on-site, real-time analysis. To this end, several portable mass spectrometers have been introduced; however, the analysis of controlled substances could be complicated by the existence of various isomers including optical isomers in which sentencing may depend on the identification of the isomer. To date very few portable separation devices are capable of separating and identifying the optical isomers. In this study, the application of the portable ultrafast capillary electrophoresis (UFCE) to the separation of controlled substances is presented and the results are compared with the results obtained from a bench-top CE system. Both a nominal mass ion trap mass spectrometer and an accurate mass orbitrap mass spectrometer were interfaced with CE using a porous tip capillary. A mixture of several controlled substances can be separated and detected using UFCE/MS in about a minute using field strengths of ≥1000V/cm. Furthermore, separation and detection of underivatized optical isomers of amphetamine, cathinone, nor-mephedrone, and pregabalin using UFCE/MS can be achieved with an analysis time of less than two minutes. Resolutions of 1.3, 3.7 and 3.8 were achieved for pregabalin, cathinone and nor-mephedrone, respectively, under UFCE/MS conditions. Amphetamine, cathinone, nor-mephedrone and pregabalin were separated and detected in about a minute, demonstrating the utility of the portable CE instrument for the analysis of controlled substances and their optical isomers. Copyright © 2016 John Wiley & Sons, Ltd.