Potential of High-Resolution Mass Spectrometry for the Detection of Drugs and Metabolites in Hair: Methoxetamine in a Real Forensic Case

Abstract

The analysis of drugs of abuse in hair and other biological matrices of forensic interest requires great selectivity and sensitivity. This is done traditionally through target analysis, with one or more analytical methods, or with different and specific preanalytical phases, and complex procedures performed by the toxicological laboratories, and there is no exception with ketamine-like compounds, such as methoxetamine, a new psychoactive substance (NPS) whose use has increased in the last decades, and continues to grow quickly year by year. More validated methods of analysis are needed to detect these substances in low concentrations selectively. Reanalyzing the samples of a former case of a polydrug consumer accused of a crime against public health in Spain, five metabolites of methoxetamine (normethoxetamine, O-desmethylmethoxetamine, dehydromethoxetamine, dihydronormethoxetamine and hydroxynormethoxetamine) were tentatively detected using a high-resolution technique that is liquid chromatography coupled to high-resolution mass spectrometry (LC-HR-MS/MS). The most selective analytical LC-HR-MS/MS method together a universal and simpler pretreatment stages has demonstrated to allow faster analysis and more sensitivity than the one performed traditionally at the INTCF laboratories, which was gas chromatography coupled to mass spectrometry (GC-MS).

Identification of 2C-B in Hair by UHPLC-HRMS/MS. A Real Forensic Case

“…Complementarily, in this case, the identification of 2C-B was related to a polyconsumption case. This relationship can also be observed in previous studies where the detection of one drug (e.g., ketamine) leads to the consideration that other substances may have been consumed concomitantly [10,18]. However, further studies need to be carried out to assume that 2C-B is related to polyconsumption.…”

“…The hair samples were taken following the guidelines addressed by the Society of Hair Testing [18]. A preanalytical method developed and used in the Madrid Department of the INTCF was employed to prepare the samples for analysis by high-resolution mass spectrometry technique for the new psychoactive substances identification [10], which was UHPLC-HRMS/MS. The methodology used was previously developed for the screening of multitargeted substances [19,20], reporting their presence or absence in hair.…”

“…As an initial method of analysis by UHPLC-HRMS/MS methodology, a single 1 µL aliquot was injected into a Vanquish Flex Binary UHPLC system, coupled with an Orbitrap Q Exactive Focus system (provided by Thermo Fisher, Hemel Hempsted, Hertfordshire, UK). The parameters for setting the instrumentation are the same reported in Matey et al [10]. Briefly, the stationary phase consisted in a phenylhexyl column (100 mm × 2.1 mm × 2.6 µm) and the mobile phase consisted in one initial eluent A, which was made of ammonium format 2 mM with 0.1% formic acid at pH 3.…”

“…So far, there are several studies carried out in hair using high-resolution analytical techniques, such as high-resolution liquid chromatography coupled to mass spectrometry (UHPLC-HRMS/MS) [10,11]. The study of analytical procedures to determine the presence or absence of 2C-B in biological matrices began in the 1990s in rats.…”

“…All the hair samples were subjected to a pretreatment stage before applying the analytical method to determine the drugs present. Different steps were used according to Matey et al [10]. Briefly, they consisted in:…”