4-methylethcathinone and cathinone

The global increase in the production and abuse of cathinone-derived New Psychoactive Substances (NPSs) has developed the requirement for rapid, selective and sensitive protocols for their separation and detection. Electrochemical sensing of these compounds has been demonstrated to be an effective method for the in-field detection of these substances, either in their pure form or in the presence of common adulterants, however, the technique is limited in its ability to discriminate between structurally related cathinone-derivatives (for example: (±)-4′-methylmethcathinone (4-MMC, 2a) and (±)-4′-methyl-N-ethylmethcathinone (4-MEC, 2b) when they are both present in a mixture. In this paper we demonstrate, for the first time, the combination of HPLC-UV with amperometric detection (HPLC-AD) for the qualitative and quantitative analysis of 4-MMC and 4-MEC using either a commercially available impinging jet (LC-FC-A) or custom-made iCell channel (LC-FC-B) flow-cell system incorporating embedded graphite screen-printed macroelectrodes. The protocol offers a cost-effective, reproducible and reliable sensor platform for the simultaneous HPLC-UV and amperometric detection of the target analytes. The two systems have similar limits of detection, in terms of amperometric detection [LC-FC-A: 14.66 μg mL(-1) (2a) and 9.35 μg mL(-1) (2b); LC-FC-B: 57.92 μg mL(-1) (2a) and 26.91 μg mL(-1) (2b)], to the previously reported oxidative electrochemical protocol [39.8 μg mL(-1) (2a) and 84.2 μg mL(-1) (2b)], for two synthetic cathinones, prevalent on the recreational drugs market. Though not as sensitive as standard HPLC-UV detection, both flow cells show a good agreement, between the quantitative electroanalytical data, thereby making them suitable for the detection and quantification of 4-MMC and 4-MEC, either in their pure form or within complex mixtures. Additionally, the simultaneous HPLC-UV and amperometric detection protocol detailed herein shows a marked improvement and advantage over previously reported electroanalytical methods, which were either unable to selectively discriminate between structurally related synthetic cathinones (e.g. 4-MMC and 4-MEC) or utilised harmful and restrictive materials in their design.

Topics: Alkaloids; Amphetamines; Chromatography, High Pressure Liquid; Electrochemistry; Forensic Sciences; Illicit Drugs; Methamphetamine; Propiophenones; Reproducibility of Results

The electrochemical sensing of new psychoactive substance(s) (NPSs), synthetic cathinone derivatives also termed "legal highs", are explored with the use of metallic modified screen-printed electrochemical sensors (SPES). It is found that no significant electrochemical enhancement is evident with the use of either in situ bismuth or mercury film modified SPES compared to the bare underlying electrode substrate. In fact, the direct electrochemical reduction of the cathinone derivatives mephedrone (4-methylmethcathinone; 4-MMC) and 4'-methyl-N-ethylcathinone (4-methylethcathinone; 4-MEC) is found to be possible for the first time, without heavy metal catalysis, giving rise to useful voltammetric electroanalytical signatures in model aqueous buffer solutions. This novel electroanalytical methodology is validated toward the determination of cathinone derivatives (4-MMC and 4-MEC) in three seized street samples that are independently analyzed with high-performance liquid chromatography (HPLC) wherein excellent agreement between the two analytical protocols is found. Such an approach provides a validated laboratory tool for the quantification of synthetic cathinone derivatives and holds potential for the basis of a portable analytical sensor for the determination of synthetic cathinone derivatives in seized street samples.

Topics: Alkaloids; Amphetamines; Bismuth; Buffers; Chromatography, High Pressure Liquid; Electrochemical Techniques; Electrodes; Forensic Sciences; Humans; Illicit Drugs; Mercury; Methamphetamine; Oxidation-Reduction; Propiophenones; Psychotropic Drugs; Solutions

4-Methylethcathinone (4-MEC) is a designer drug that is structurally similar to mephedrone. This substance was identified in many drug seizures analyzed in the Institute of Forensic Research (IFR). This paper describes three of the first cases in which both powders and biological material were secured at the same time and delivered to the IFR for toxicological analysis. The first case concerned a man who died in a car crash. The second case describes a death associated with multiple-drug intake, including 4-MEC. In this case, however, the death was the result of an overdose of para-methoxyamphetamine (PMA). In the third case, the man was arrested for possession of illicit drugs. Analysis of powders was carried out using gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography with diode array detection (HPLC-DAD). The purity of 4-MEC found in powder samples was 51% and 78%. Analyses of biological material were carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). 4-MEC was found in blood samples at concentrations of 46, 56 and 152 ng/mL.

Topics: Adult; Alkaloids; Amphetamines; Central Nervous System Stimulants; Chromatography, High Pressure Liquid; Designer Drugs; Forensic Toxicology; Gas Chromatography-Mass Spectrometry; Gastrointestinal Contents; Humans; Male; Molecular Structure; Powders; Propiophenones; Substance Abuse Detection; Substance-Related Disorders