Potential Of High-Resolution Mass Spectrometry For The Detection Of Drugs And Metabolites In Hair: Methoxetamine In A Real Forensic Case

Methoxetamine and its metabolites: Postmortem determination in body fluids of human cadaver

We report the forensic case of a 42-year-old man, a known drug user, who died at home and whose body was only discovered 2 months later. Autopsy was performed on a corpse in the late postmortem stage where no apparent cause of death was found. A toxicological screening of biological materials (blood, urine and gastric content) using liquid chromatography with different types of mass detection (ion trap and high-resolution) revealed the presence of methoxetamine (MXE), a ketamine analog, and its metabolites. MXE and a number of its metabolites (e.g., O-desmethyl, N-desethyl, hydroxy, glucuronides and sulfates) were identified in urine. Based on the results, a method using liquid chromatography with tandem mass spectrometry was developed and validated for the determination of MXE concentration in biological materials. The following values of MXE concentration were found: blood-3.6 ng/mL, urine-70.5 ng/mL and gastric content-18.0 ng/mL. Given the absence of other drugs, medications and poisons, it can be inferred that despite relatively low blood concentrations, MXE contributed to the victim's death. The present case demonstrates that even after 2 months, MXE and its several metabolites can be detected and determined in the human cadaver at a relatively advanced stage of decomposition.

Screening strategy for ketamine-based new psychoactive substances using fragmentation characteristics from high resolution mass spectrometry

Recreational designer drugs called new psychoactive substances (NPS) are emerging and pose enormous risks to public health. Detection of recently discovered or unreported NPS remains a huge challenge by using traditional targeted mass spectrometry methods. Here a novel screening strategy was developed to detect both known and novel analogs of NPS based on fragmentation characteristics from liquid chromatography-high resolution mass spectrometry (LC-HRMS). The HRMS fragmentation pathway of one selected NPS family was investigated to form a database containing predicted drugs as well as their mass characteristics. During the study, an unexpected substituent effect was found to distinguish geometric isomers. Seventy-eight seized samples were analyzed using this strategy, four ketamine-based NPS were detected and three of them were newly marketed. The substituent effect predicted the position of their phenylic substituent, the results were confirmed by NMR.

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.

A comprehensive UHPLC-MS/MS screening method for the analysis of 98 New Psychoactive Substances and related compounds in human hair

In this study, a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the targeted analysis of 98 New Psychoactive Substances (NPS) from the hair matrix. The monitored compounds included various chemical classes (7 phenethylamines, 10 tryptamines, 18 cathinones, 24 synthetic opioids, and 38 synthetic cannabinoids) with emphasis given to newly emerged NPS. The method employed a direct extraction process through the incubation of hair samples (25 mg) and internal standards with M3® reagent at 100 °C for 60 min, followed by extract purification through acid and basic liquid-liquid micro-extraction (LLME). Extracted compounds were analyzed through LC-MS/MS system operating in multiple reaction monitoring mode. NPS were separated in 9.5 min with a Poroshell 120 EC-C18 column (2.7 μm, 4.6 × 50 mm) using a gradient eluting mobile phase composed of water and acetonitrile/water (95:5) both containing 0.1 % of formic acid. The developed and validated method shows a good precision (≤ 15 %), linearity (R² between 0.993 and 0.999), selectivity, and sensitivity (LOD: 0.6-10.3 pg mg^-1 and LOQ: 2.1-34.4 pg mg^-1). The method showed also reduced matrix effect and acceptable recovery for most of the targeted compounds. Our results showed that this method is suitable for quantifying NPS in hair matrix and could be employed in the context of routine analyses in analytical laboratories.

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.