A comparison of single quadrupole mass detection and diode array ultraviolet detection interfaced to ultra-high performance supercritical chromatography for the quantitative analysis of synthetic cathinones.

A comparison of single quadruple mass spectrometry and diode array-ultraviolet (PDA-UV) detection interfaced to ultra-high performance supercritical fluid chromatography was performed for the quantitative analysis of synthetic cathinones. Synthetic cathinones, also known as "bath salts", are derived from cathinone, a component of the khat plant. For 15 controlled solutes linearity, repeatability, and limits of detection were determined using both UV and MS detection. Quantitation studies were performed using the above detectors for 19 mixtures of up to 4 of the above compounds with an adulterant to simulate seized samples. MS detection provided approximately an order of magnitude greater linearity range and allowed for two to three orders of magnitude lower limits of detection than UV detection. Both detection techniques exhibited similar results of analysis and comparable repeatability. The latter detection mode which provided significantly high linearity correlation coefficients (0.9994 ≤ R2 ≤ 1.0000) would be preferred for quantitative analysis.

Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended.