Enantiomer Profiling of Methamphetamine in White Crystal and Tablet Forms (Ma Old) Using LC–MS-MS

Abstract

At the global level, seizures of crystalline methamphetamine (MA) and MA tablets have risen to a new high, indicating that the substance is an imminent threat. MA enantiomer profiling was a useful tool to investigate the prevalence of MA abuse, the intrinsic characteristics of the seized samples and the trends of precursors. In this work, the distribution of enantiomers in clandestine MA crystals and tablets seized mainly in the Yangtze River Delta region, China, from 2008 to 2014 were identified. The MA samples were diluted with internal standard methanol solution, and analyzed by LC-MS-MS. The detection limits of the enantiomers were 0.04 μg/L. The limit of quantification was 0.1 μg/L. As little as 0.2% of the R-enantiomer ratio could be determined. Standard calibration curves of S- and R-MA showed good linearity in the range of 0.1-80 μg/L (r(2) > 0.995). All of the seizures were optically pure S-enantiomer in the years 2008 and 2009. Seized samples containing a slight amount of R-MA began to appear in 2010 and increased in the year 2014. No racemic mixture or R-isomer of MA was seized. From this study, we could find out that smuggling routes and/or precursors might be silently changing in the Yangtze River Delta region, China.

Accelerated quantification of amphetamine enantiomers in human urine using chiral liquid chromatography and on-line column-switching coupled with tandem mass spectrometry

“…Keeping this in mind, the measured urine samples from suspected MA abusers can be classified into three groups according to the observed stereoisomeric profiles of AM and the assumed composition of the consumed MA: I) only S-AM present, this indicates misuse of pure S-MA; II) R/S ratios between 0.01 and 0.07 or R-AM concentrations < LLOQ, this might be due to intake of S-MA containing small amounts of R-MA; III) R/S ratios between 0.14 and 0.47, consumption of racemic MA. This classification is supported by the findings reported by Li et al [24], Nagai et al [39] and Wang et al [40].…”

Determination of the enantiomeric composition of amphetamine, methamphetamine and 3,4‐methylendioxy‐N‐methylamphetamine (MDMA) in seized street drug samples from southern Germany

“…The majority of the seized crystals there also contained pure (S)-methamphetamine, although different fractions of pure (R)-methamphetamine and racemic and non-racemic mixtures were also found. [32][33][34][35][36][37][38] Two of these studies observed a decreasing trend in seizures of the more potent (S)-enantiomer. 32,33 The latter was also observed in an American study from 2005 to 2012, where, in addition to pure (S)-methamphetamine, mainly nonracemic mixtures were found.…”

Shape matters: The application of activity‐based in vitro bioassays and chiral profiling to the pharmacological evaluation of synthetic cannabinoid receptor agonists in drug‐infused papers seized in prisons

“…Münster‐Müller et al describes a novel stable isotope analysis and impurity‐profiling workflow, using the SCRAs MDMB‐CHMICA (2) and Cumyl‐5F‐PINACA [1‐(5‐fluoropentyl)‐ N ‐(2‐phenylpropan‐2‐yl)‐1 H ‐indazole‐3‐carboxamide] (9) , for the detection of synthesis precursor/by‐product impurities in seized herbal materials and potential source attribution 38–41 . Chiral profiling has been applied previously to illicitly produced drugs including amphetamine and methamphetamine for intelligence purposes, 42–44 although the methodology is rarely routinely employed in forensic drug testing laboratories. We suggest that chiral profiling could be applied to chiral valinate and tert ‐leucinate SCRAs in addition to stable isotopic and impurity profiling; however, the potential utility of such chiral profiling is currently unknown as, to date, there have been no large‐scale studies to determine the variation of enantiopurity of these SCRAs in seized samples.…”