A validated GC-MS method for ketamine and norketamine in hair and its use in authentic cases

Identification of surface-enhanced Raman spectroscopy using hybrid transformer network

Surface-enhanced Raman Spectroscopy (SERS) is extensively implemented in drug detection due to its sensitivity and non-destructive nature. Deep learning methods, which are represented by convolutional neural network (CNN), have been widely applied in identifying the spectra from SERS for powerful learning ability. However, the local receptive field of CNN limits the feature extraction of sequential spectra for suppressing the analysis results. In this study, a hybrid Transformer network, TMNet, was developed to identify SERS spectra by integrating the Transformer encoder and the multi-layer perceptron. The Transformer encoder can obtain precise feature representations of sequential spectra with the aid of self-attention, and the multi-layer perceptron efficiently transforms the representations to the final identification results. TMNet performed excellently, with identification accuracies of 99.07% for the spectra of hair containing drugs and 97.12% for those of urine containing drugs. For the spectra with additive white Gaussian, baseline background, and mixed noises, TMNet still exhibited the best performance among all the methods. Overall, the proposed method can accurately identify SERS spectra with outstanding noise resistance and excellent generalization and holds great potential for the analysis of other spectroscopy data.

Green Analytical Toxicology procedure for determination of ketamine, its metabolites and analogues in oral fluid samples using dispersive liquid-liquid microextraction (DLLME)

New psychoactive substances (NPS) are often synthesized via small changes in the molecular structure, producing drugs whose effect and potency are not yet fully known. Ketamine is one of the oldest NPS, with therapeutic use in human and veterinary medicine authorized in several countries, being metabolized mainly into norketamine and 6-hydroxy-norketamine. Furthermore, two structural analogues of ketamine have recently been identified, deschloroketamine and 2-fluorodeschloroketamine, marketed as drugs of abuse. To comply with Green Analytical Toxicology (GAT) fundamentals, miniaturized techniques such as dispersive liquid-liquid microextraction (DLLME) were employed to determine toxicants in biological fluids. An analytical method for determining ketamine, its metabolites and its analogues in oral fluid was fully developed and validated by using DLLME and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The extraction parameters were optimized by multivariate analysis, obtaining the best conditions with 200 μL of sample, 100 μL of methanol as dispersive solvent and 50 μL of chloroform as extractor solvent. Linearity was obtained from 10 to 1,000 ng/mL, with limit of detection (LOD) and lower limit of quantification (LLOQ) at 10 ng/mL. Imprecision (% relative standard deviation) and bias (%) were less than 8.2% and 9.5%, respectively. The matrix effect did not exceed 10.6%, and the recovery values varied from 24% to 42%. No matrix interference and good selectivity in the evaluation of 10 different sources of oral fluid and 42 drugs at 500 ng/mL, respectively, were observed. The method was applied in the analysis of 29 authentic oral fluid samples and had its green characteristic evaluated by three different tools: the Green Analytical Procedure Index (GAPI), the Analytical Eco-Scale and the Analytical GREEnness (AGREE) metrics.

Children victims of drug abuser parents: Hair testing as a forensic tool to assess exposure-A cohort of 37 cases from Spain

Hair testing is a useful tool to investigate suspected pediatric exposure to drugs of abuse. Newborns and young children are at high risk of exposure to drugs of abuse from parents or caregivers who consumed these substances, a fact prosecuted by Spanish authorities as child abuse. A retrospective study based on a cohort of 37 cases classified using several parameters, which involve children under 12 years old, were analyzed at the Drugs Laboratory of the National Institute of Toxicology and Forensic Sciences (Madrid, Spain) between 2009 and 2021. Hair samples were tested for the presence of opiates, cocaine, ketamine, amphetamines, methadone, and cannabis using a gas chromatography-mass spectrometry (GC-MS) method. A 59% of the studied children had ages in the range of 1-3 years old, and in 81% of cases, victims required hospitalization. In 81% of cases (n = 30), hair was submitted only or in combination with other samples, and these were classified in four categories according to analyzed samples: A (only hair), B (hair and blood), C (hair and urine), and D (hair, blood, and urine). The 93.3% of these cases (n = 28) showed a positive result of cannabinoids (THC and CBN in hair and THC-COOH in urine; 71.4% n = 20), cocaine and metabolites (benzoylecgonine and cocaethylene; 46.4% n = 13), opiates (morphine and 6-acetylmorphine), and amphetamines (MDMA and MDMA; 3.10% n = 1). Hair analysis matched positive results in cases where urine screening test was carried out previously (n = 24) and in those cases where blood and/or urine were also submitted (35.6% n = 11). As a conclusion, hair analysis was confirmed as a useful tool to detect previous exposure to acute poisoning events in children.

Surface-enhanced Raman imaging through sprayed probes for the application in chemical visualization of methamphetamine within fingerprints

For fingerprint-involved forensic investigations, cyanoacrylates and inorganic nanophosphors are mostly used for fingerprint visualization. However, methods to simultaneously report fingerprint images and the corresponding specific chemical information have yet to be realized. In this work, chemical visualization of the analytes in fingerprints is achieved through surface-enhanced Raman spectroscopy (SERS) measurements with the aid of spray-dispersed gold nanorods (AuNRs). The optimal coverage of AuNRs was studied by theoretical simulations and experimental operations. A rapid sampling of fingerprints with the chemical of interest was developed by tuning the spray parameters. In particular, the SERS imaging of methamphetamine in fingerprint latent was attempted by addressing the SERS spectral features of methamphetamine. This chemical visualization method reflects both the graphical and chemical characteristics of fingerprints in a single batch measurement, in which methamphetamine can be detected and mapped at the concentration of 10^-5 M. The data processing approach was also modified by employing relevant logical judgments. The improved SERS images with sharpened patterns of fingerprints were obtained by involving the scored multi-peak judgments.

Microextraction by Packed Sorbent as a Clean-up Approach for the Determination of Ketamine and Norketamine in Hair by Gas Chromatography--Tandem Mass Spectrometry

The use of new psychoactive substances has been increasing and constitutes a social and public health problem, and hence, toxicological analysis has become of utmost importance for the detection of such substances. In this article, we present the development and full validation of a simple, user and environmentally friendly, cheap and suitable method for the determination of ketamine and its main metabolite norketamine in hair samples. The procedure included using a miniaturized procedure-microextraction by packed sorbent with mixed-mode sorbent-for sample clean-up. Organic solvents use was minimal, and it was possible to obtain a linear method (0.05-10 ng/mg for both analytes). The extraction efficiency ranged from 32 to 61%, which did not impair sensitivity. The method proved to be selective, precise, accurate and suitable for routine analysis for the determination of said compounds in 50-mg hair samples.

Amphetamine, methamphetamine, and MDMA in hair samples from a rehabilitation facility: Validation and applicability of HF-LPME-GC-MS

INTRODUCTION

It is known that drug abuse jeopardizes economic and social development. Toxicological analyses can guide prevention and treatment strategies in rehabilitation facilities. The current greatest challenge is finding easily adaptable and less costly sensitive methods that meet the principles of green chemistry. Hair, as a biological matrix, has several advantages, and its ability to detect consumption for longer periods keeping the matrix stable and unaltered stands out. This manuscript addresses the use of a miniaturized technique in an alternative matrix, by making use of a reduced amount of solvents to quantify amphetamines, aiming to guide prevention and treatment strategies in rehabilitation facilities.

METHODS

A Hollow Fiber Liquid-phase Microextraction (HF-LPME) technique for extracting amphetamines from hair samples with Gas Chromatography-Mass Spectrometry (CG-MS) was validated, adapted, and applied to ten samples from patients of a rehabilitation facility.

RESULTS

The technique proved to be sensitive, accurate, precise, and not affected by interference from the biological matrix and the linear range for the analytes was 0.2 to 20 ng mg ^-1. The three analytes were quantified in the samples analyzed. It is worth stressing that the patients were young.

CONCLUSION

The HF-LPME-GC-MS technique complied with the principles of green chemistry, and proved to be a sensitive technique, adaptable to the routine of common laboratories. Validation in the analysis phase with authentic samples, thus, showed that it can be an important tool for preventing and controlling drug addiction.

Difficulties interpreting concentrations in fatal cases: example of 2,5-dimethoxy-4-chloroamphetamine

PURPOSE

Death related to the use of drugs is evident when drugs are detected in biological matrices within toxic levels, but sometimes it can be less obvious. Intoxications after 2,5-dimethoxy-4-chloroamphetamine (DOC) use are occurring but up to date, only one fatality has been reported. Here we present the case of a young woman admitted to hospital as she presented vomiting, convulsions and cardiorespiratory arrest.

METHODS

Blood ethanol concentration was determined using gas chromatography with flame ionization detection and toxicological screenings (blood, gastric content and hair samples) were performed using liquid chromatography with diode array detection, gas chromatography or liquid chromatography with mass spectrometry detection.

RESULTS

Her health state declined with cardiac troubles, organs failure and cerebral edema till death occurring 4 days later. The autopsy revealed the presence of hemorrhagic infiltration inside the left ventricle, pulmonary edema and hemorrhagic infiltration of the terminal ileum. The analysis of biological fluids confirmed the presence of DOC (< 10 ng/mL in cardiac blood sample), buprenorphine, cocaine and cannabis metabolites. The analysis of hair highlighted a history of drugs abuse.

CONCLUSION

In the absence of evident identified cause, the hypothesis of a death due to acute drugs use within a history of chronic consumption of drugs has been put forward. The concentration of some substances such as new psychoactive substances can be low in biological matrices but the toxic effects can be additive and lead to death even within young people, hence the importance of the knowledge of consumption history.

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.

Determination of Ketamine and Norketamine in Hair and Evaluation of Polydrug Use in Ketamine Abusers Using Hair Analysis in Korea

This study evaluated hair samples from 28 subjects who tested positive for ketamine at Seoul Institute National Forensic Service in Korea between 2016 and 2017. Ketamine in the hair was extracted using a solution of 1% hydrochloric acid in methanol for 16 h. Extracts were analyzed using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS-MS). The LC-MS-MS method was validated by determining the limit of detection (LOD), limit of quantification (LOQ), linearity, intra- and inter-accuracy, precision and matrix effect. In 59 ketamine-positive hair or hair segments from 28 ketamine abusers, the ketamine concentration was found to be in the range of 0.011-335.8 ng/mg (mean, 13.6; median, 1.8), and the norketamine concentration was found to be in the range of 0.001-35.7 ng/mg (mean, 7.5; median, 0.44). The ratio of norketamine to ketamine concentrations in hair was in the range of 0.01-1.46 (mean, 0.34; median, 0.26). The distribution of ketamine concentration in hair samples was as follows: 0.01-0.1 ng/mg in 11 samples (18.6%), 0.1-5 ng/mg in 33 samples (55.9%), 5-10 ng/mg in 4 samples (6.8%), 10-15 ng/mg in 2 samples (3.4%), 15-20 ng/mg in 4 samples (6.8%), 40-45 ng/mg in 2 samples (3.4%), 45-50 ng/mg in 1 sample (1.7%) and >100 ng/mg in only 2 samples (3.4%). In the hair of ketamine abusers, 26 of 28 subjects were detected simultaneously ketamine with other drugs, including methylenedioxymethamphetamine (MDMA; n = 9), methamphetamine (MA; n = 3), MDMA/MA (n = 3), MDMA/para-methoxyamphetamine (PMA; n = 3), MDMA/PMA/MA (n = 2), cocaine (n = 1) and other drugs (n = 5, propofol, zolpidem or benzodiazepines). Along with ketamine, other controlled drugs were detected in most of the hair samples: MDMA (60.7%), MA (28.6%), PMA (17.9%), zolpidem (17.9%) and propofol (14.3%) in the frequency of abuse. In conclusion, most of the ketamine abusers (92.9%) were polydrug abusers, who were concomitantly abusing other controlled substances.

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.

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 (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).