Analysis of purity and cutting agents in street mephedrone samples from South Wales

Mephedrone (4-methylmethcathinone) was banned in the UK under the Misuse of Drugs Act in April 2010 and by the EU in December 2010. Banning drugs is intended to reduce harm by limiting access and causing a reduction in purity, although this may cause overdoses when users cannot predict the correct dose. In this study, 119 mephedrone samples from South Wales were collected between November 2011 and March 2013. Mephedrone purity was determined by gas chromatography–mass spectrometry, and cutting agents were identified using Fourier transform infrared spectroscopy (FTIR). Mean mephedrone purity was 68.2 %, with a standard deviation of 24.9 %. A clear time trend was observed, with mephedrone purity declining from the start of our collection period. The mean purity decreased from 80 % in the first 10 samples collected to 50 % in the last 10 samples collected. Cutting agents were identified in 48 samples by FTIR. The most common were monosodium glutamate, creatine, and sucrose. Three samples were found to contain both monosodium glutamate and sucrose and their purity was very low at 33 %, suggesting that they were cut in two phases. Surprisingly, no adulterants, such as the topical anesthetics that are used to cut cocaine, were detected. 4-Fluoromethcathinone and 4-methylethcathinone were the only other psychoactive substances detected.