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

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 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 highest analytical selectivity of 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.

Prevalence study of drugs and new psychoactive substances in hair of ketamine consumers using a methanolic direct extraction prior to high-resolution mass spectrometry.

Few studies have reported the prevalence or incidence about the consumption of new psychoactive substances (NPS). The hair analysis can be useful for this purpose. At the present, ketamine is the most consumed arylcyclohexylamine associated to young consumers and polyconsumption profiles. For this reason, ketamine consumer cases become very interesting to provide information on NPS prevalence. In this work, ten former cases of the National Institute of Toxicology and Forensic Science (INTCF) of Madrid Department (INTCFM), all of them belonging to defendants accused of crimes against public health and who had been found positive to ketamine, were reassessed. At the first toxicological analysis of those hair samples, a positive consume in ketamine had been determined by gas chromatography coupled to mass spectrometry (GC-MS). In this work, the same hair samples were reanalyzed by high-resolution mass spectrometry ( UHPLC-HRMS/MS) using an incubation methanolic extraction combined with a single, simpler, non-selective and direct sample pre-treatment. After corroborating the GC-MS results previously obtained for the same samples, the detection of additional NPS using this new methodology evidenced its benefits and opened the possibility to perform a NPS prevalence study. In brief, in those cases with a positive consumption in ketamine, a polyconsumption of other drugs and NPS was found, including different arylcyclohexylamines as deschloroketamine, 3-MeO-PCP and methoxetamine; and cathinones as methylmetcathinone and N-ethyl-pentylone.

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

The analysis of drugs of abuse in hair and other biological matrices of forensic interest requires great selectivity and sensitivity. This has been traditionally achieved through target analysis, using one or more analytical methods that include different preanalytical stages, and more complex procedures followed by toxicological laboratories. There is no exception with 2C-series drugs, such as 2C-B, a new psychoactive substance (NPS), which use has emerged and significantly increased, year by year, in the last decades. Continuously new analytical methods are required to selectively detect and identify these new marketed substances at very low concentrations. In this case report, one former case of a polydrug consumer (charged of a crime against public health in Spain) was reanalyzed in hair matrix. In this reanalysis, 2C-B has been positively detected and identified using liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS). The most selective analytical UHPLC-HRMS/MS method alongside a universal and simpler pretreatment methodology has opened up more possibilities for the detection of substances of different chemical structure and optimization of different HRMS/MS detection approaches allowing the identification of 2-CB in the hair of a real forensic case.

Introducing ATR-FTIR Spectroscopy through Analysis of Acetaminophen Drugs: Practical Lessons for Interdisciplinary and Progressive Learning for Undergraduate Students.

Infrared (IR) spectroscopy is a vibrational spectroscopic technique useful in chemical, pharmaceutical, and forensic sciences. It is essential to identify chemicals for reasons spanning from scientific research and academic practices to quality control in companies. However, in some university degrees, graduate students do not get the proficiency to optimize the experimental parameters to obtain the best IR spectra; to correlate the IR spectral bands with the molecular vibrations (chemical elucidation); to have some criteria for any substance identification (especially relevant in quality control to recognize counterfeit); and to apply chemometrics for comparing, visualizing, and classifying the IR spectra. This work presents an experimental laboratory practice for an introductory teaching of the IR instrumental conditions in the identification of substances based on visual spectra comparison and statistical analysis and matching. Then, the selected IR conditions are applied to different commercial drugs, in the solid state or in solution, mostly composed of acetaminophen. Finally, the students apply chemometrics analysis to the IR data. This practice was designed for the training in a chemistry subject for undergraduate students of the chemistry, pharmacy, or forensics degrees, among others related to science, medical, food, or technological sciences.

Author Correction: Increasing neurogenesis refines hippocampal activity rejuvenating navigational learning strategies and contextual memory throughout life.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Increasing neurogenesis refines hippocampal activity rejuvenating navigational learning strategies and contextual memory throughout life.

Functional plasticity of the brain decreases during ageing causing marked deficits in contextual learning, allocentric navigation and episodic memory. Adult neurogenesis is a prime example of hippocampal plasticity promoting the contextualisation of information and dramatically decreases during ageing. We found that a genetically-driven expansion of neural stem cells by overexpression of the cell cycle regulators Cdk4/cyclinD1 compensated the age-related decline in neurogenesis. This triggered an overall inhibitory effect on the trisynaptic hippocampal circuit resulting in a changed profile of CA1 sharp-wave ripples known to underlie memory consolidation. Most importantly, increased neurogenesis rescued the age-related switch from hippocampal to striatal learning strategies by rescuing allocentric navigation and contextual memory. Our study demonstrates that critical aspects of hippocampal function can be reversed in old age, or compensated throughout life, by exploiting the brain's endogenous reserve of neural stem cells.