Forensic analysis of mesembrine alkaloids in Sceletium tortuosum by nonaqueous capillary electrophoresis mass spectrometry

Abstract

The consumption of legal and illegal drugs follows an organic trend comparable to the current trend in food consumption. The investigation of such drugs is therefore of interest to characterize the active ingredients of plants and drug preparations. A new method of nonaqueous capillary electrophoresis coupled to mass spectrometry (NACE-MS) as a powerful tool for the separation of complex alkaloid mixtures in difficult matrices is presented in this study for the analysis of samples of Sceletium tortuosum and drug products called Kanna made thereof. The method was found to be suitable for the investigation of the alkaloid composition and relative quantification of the ingredients. It proved of value to separate a large number of isobaric compounds, most probably including diastereomers, double-bond isomers, and further structurally closely related compounds. A comparison of plant samples from different vendors, self-fermented samples, and products ready for consumption was made. The high separation power obtained allowed a better description of the chemotypic differences of plant samples as well as Kanna preparations compared to other methods presented in the literature so far. Thus, the use of the NACE-MS enables a new perspective on the alkaloid profile of Sceletium species.

GC-MS, LC-MSn, LC-high resolution-MSn, and NMR studies on the metabolism and toxicological detection of mesembrine and mesembrenone, the main alkaloids of the legal high “Kanna” isolated from Sceletium tortuosum

“…92 % purity) were obtained from Sigma Aldrich (Steinfurt, Germany), basic aluminum oxide (activity stage І, 0.063-0. 2 m m ) , t e t r a m e t h y l s i l a n e i n C D C l 3 , a n d 3 -(trimethylsilylpropyl)propionic acid-d 4 sodium salt in D 2 O, and the internal standards for calibrating 1 H and 13 C chemical shifts were from Merck (Darmstadt, Germany), acetonitrile (LC-MS grade), ammonium formate (analytical grade), ethanol (LC-MS grade), formic acid (for mass spectrometry), methanol (LC-MS grade), and all other chemicals and biochemicals from VWR (Darmstadt, Germany). Ready-to-use pH 10 buffer for the conversion of the hydrochlorides to the free amines was delivered from Roth (Karlsruhe, Germany).…”

CE-MS in Forensic Sciences with Focus on Forensic Toxicology

“…Roscher et al reported a NACE-ion trap MS method as a tool for unraveling complex alkaloid mixtures present in the samples of Sceletium tortuosum and in drug products called Kanna made thereof, containing a large number of isobaric compounds [75]. Analysis of Kanna alkaloids is particularly challenging, because of the complexity of the alkaloid mixture including a large number of diastereomers, their poor solubility in water, and the lack of several alkaloid standards.…”

Advance of CE and CEC in phytochemical analysis (2012–2013)

“…Especially, NACE, using organic solvents instead of water, was used in CZE. ACN , methanol , 1‐propanol , or their mixture were commonly used. Besides, a novel and very simple NACE method has been established for analyzing seven quaternary alkaloids in Coptis rhizome using 1‐alkyl‐3‐methylimidazolium tetrafluoroborate‐based ionic liquid (IL) as BGE.…”

“…The main drawback of CE is the low detection capability, and the utilization of hyphenated MS detection offers high sensitivity and the possibility of structurally characterizing the analytes. Sheath liquid is widely used for transferring analytes from liquid phase of CE to gas phase of MS . Actually, various sheathless interfaces have been developed to enhance the concentration sensitivity of CE–MS .…”

“…Indeed, sheathless CE‐MS has been used for metabolome analysis . Great success has been achieved in online coupling of CE to MS (CE‐MS) using ESI . Volatile electrolyte buffer, such as formic acid , ammonium acetate , ammonium acetate‐acetic acid , ammonium formate‐acetic acid , were commonly used.…”