Simultaneous determination of 75 abuse drugs including amphetamines, benzodiazepines, cocaine, opioids, piperazines, zolpidem and metabolites in human hair samples using liquid chromatography-tandem mass spectrometry

Comprehensive detection of lysergic acid diethylamide (LSD) in forensic samples using carbon nanotube screen-printed electrodes

Lysergic acid diethylamide (LSD) is a prevalent psychoactive substance recognized for its hallucinogenic properties, often encountered in blotter papers for illicit consumption. Given that LSD ranks among the most widely abused illicit drugs globally, its prompt identification in seized samples is vital for forensic investigations. This study presents, for the first time, an electrochemical screening method for detecting LSD in forensic samples, utilizing a multi-wall carbon nanotube screen-printed electrode (SPE-MWCNT). The LSD detection process was optimized on SPE-MWCNT in a phosphate buffer solution (0.1 mol L-1, pH 12.0) using square wave voltammetry (SWV). The combined use of SPE-MWCNT with SWV displayed robust stability in electrochemical responses for both qualitative (peak potential) and quantitative (peak current) LSD assessment, with a relative standard deviation (RSD) of less than 5% across the same or different electrodes (N = 3). A linear detection range was established between 0.16 and 40.0 μmol L-1 (R2 = 0.998), featuring a low limit of detection (LOD) of 0.05 μmol L-1. Interference studies with twenty-three other substances, including groups of phenethylamines typically found in blotting papers (e.g., NBOHs and NBOMes) and traditional illicit drugs, were performed, revealing a highly selective response for LSD using the proposed method. Consequently, the integration of SPE-MWCNT with SWV offers a robust tool for qualitative and quantitative LSD analysis in forensic applications, providing rapid, sensitive, selective, reproducible, and straightforward preliminary identification in seized samples.

Uncertainty Evaluation for the Quantification of Urinary Amphetamine and 4-Hydroxyamphetamine Using Liquid Chromatography-Tandem Mass Spectrometry: Comparison of the Guide to the Expression of Uncertainty in Measurement Approach and the Monte Carlo Method with R

Estimating the measurement uncertainty (MU) is becoming increasingly mandatory in analytical toxicology. This study evaluates the uncertainty in the quantitative determination of urinary amphetamine (AP) and 4-hydroxyamphetamine (4HA) using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method based on the dilute-and-shoot approach. Urine sample dilution, preparation of calibrators, calibration curve, and method repeatability were identified as the sources of uncertainty. To evaluate the MU, the Guide to the Expression of Uncertainty in Measurement (GUM) approach and the Monte Carlo method (MCM) were compared using the R programming language. The MCM afforded a smaller coverage interval for both AP (94.83, 104.74) and 4HA (10.52, 12.14) than that produced by the GUM (AP (92.06, 107.41) and 4HA (10.21, 12.45)). The GUM approach offers an underestimated coverage interval for Type A evaluation, whereas the MCM provides an exact coverage interval under an abnormal probability distribution of the measurand. The MCM is useful in complex settings where the measurand is combined with numerous distributions because it is generated from the uncertainties of input quantities based on the propagation of the distribution. Therefore, the MCM is more practical than the GUM for evaluating the MU of urinary AP and 4HA concentrations using LC-MS/MS.

Metabolic Profile Analysis of Designer Benzodiazepine Etizolam in Zebrafish and Human Liver Microsomes

As one of the most widely abused designer benzodiazepines worldwide, Etizolam is characterized by its high addiction potential, low production cost, and difficulty in detection. Due to the rapid metabolism of Etizolam in the human body, the probability of detecting the Etizolam parent drug in actual case samples by forensic personnel is low. Therefore, without detecting the parent drug, analysis of Etizolam metabolites can help forensic personnel provide references and suggestions on whether the suspect has taken Etizolam. This study simulates the objective metabolic process of the human body. It establishes a zebrafish in vivo metabolism model and a human liver microsome in vitro metabolism model to analyze the metabolic characteristics of Etizolam. A total of 28 metabolites were detected in the experiment, including 13 produced in zebrafish, 28 produced in zebrafish urine and feces, and 17 produced in human liver microsomes. The UPLC-Q-Exactive-MS technology was used to analyze the structures and related metabolic pathways of Etizolam metabolites in zebrafish and human liver microsomes, and a total of 9 metabolic pathways were identified, including monohydroxylation, dihydroxylation, hydration, desaturation, methylation, oxidative deamination to alcohol, oxidation, reduction acetylation, and glucuronidation. Among them, metabolites involving hydroxylation reactions (including monohydroxylation and dihydroxylation) accounted for 57.1% of the total number of potential metabolites, indicating that hydroxylation may be the major metabolic pathway of Etizolam. Based on the response values of each metabolite, monohydroxylation (M1), desaturation (M19), and hydration (M16) were recommended as potential biomarkers for Etizolam metabolism. The experimental results provide reference and guidance for forensic personnel in identifying Etizolam use in suspects.

Concentrations of LSD, 2-oxo-3-hydroxy-LSD, and iso-LSD in hair segments of 18 drug abusers

Lysergic acid diethylamide (LSD) is one of the most widely abused hallucinogens, which can alter consciousness, produce mental disorder, and cause harmful behavior. 1-Propionyl-LSD (1 P-LSD), a novel derivative of LSD, has the similar hallucinogenic effect. It is a control substance in several countries. 1 P-LSD can act as a prodrug for LSD and is rapidly hydrolyzed to LSD in humans. Therefore, LSD use should be confirmed by the absence of 1 P-LSD and in the detection of LSD. Here, we describe a LC-MS/MS method for the simultaneous extraction of LSD, iso-LSD, 2-oxo-3-hydroxy-LSD, and 1 P-LSD from hair. Hair samples (25 mg) were pulverized by cryogenic grinding in methanol. The limits of detection were 0.2-1 pg/mg and the limits of quantification were 0.5-2 pg/mg. This method was validated and applied to hair samples from 18 suspects who may have used LSD. Segmental hair analysis revealed a decrease in the LSD concentrations from the proximal to the distill end, while 1 P-LSD was not detected in any hair segments. The interpretation of hair analysis results of LSD still remains difficult. Nevertheless, concentrations of LSD and iso-LSD in human hair from 18 LSD users were reported. LSD concentrations were from <LOQ to 4.0 pg/mg (n = 18, median 1.5 pg/mg) in the proximal 0-3 cm segment, from <LOQ to 1.8 pg/mg (n = 8) in the 3-6 cm segment, and from <LOQ to 0.6 pg/mg (n = 4) in the 6-9 cm segment. Iso-LSD ranged from <LOQ to 1.4 pg/mg (n = 4) in the 0-3 cm segment and was detectable only in one 3-6 cm segment. To our knowledge, this is the first study to monitor LSD together with 1 P-LSD in hair.

Determination of amphetamines, ketamine and their metabolites in hair with high-speed grinding and solid-phase microextraction followed by LC-MS

A novel hair sample pre-treatment method based on high-speed grinding and solid-phase microextraction (SPME) had been applied for the determination of amphetamines, ketamine and their metabolites in hair samples by liquid chromatography-mass spectrometry (LC-MS). A 20 mg sample of hair was ground with 2 mL of saturated sodium carbonate solution using a high-efficiency hair grinder with 70 Hz oscillation for 2 min at 4 °C. After centrifuging, 1.5 mL of the supernatant was transferred and treated with SPME by direct immersion (DI-SPME). The target analytes extracted by fibre were desorbed and analysed using LC-MS. Under the optimum conditions, a recovery of 90.2%–95.8% was obtained for all analytes. The analytical method was linear for all analytes in the range from 0.2 to 10 ng/mg with the correlation coefficient ranging from 0.9985 to 0.9993. The detection limits for all analytes were estimated to be 0.067 ng/mg. The accuracy (mean relative error) was within ±6.9% and the precision (relative standard error) was less than 6.8%. The combination of high-speed grinding of hair and SPME had the advantages of being easy to perform, environment-friendly and high in detection sensitivity. The proposed method offered an alternative analytical approach for the sensitive detection of drugs in hair samples for forensic purposes.

Key Points

The SPME was involved for the determination of drugs in hair with LC-MS.

The hair high-speed grinding combined with SPME was firstly developed.

Good linearity, sensitivity, recovery and precision were achieved.

A Systematic Review of Metabolite-to-Drug Ratios of Pharmaceuticals in Hair for Forensic Investigations

After ingestion, consumed drugs and their metabolites are incorporated into hair, which has a long detection window, ranging up to months. Therefore, in addition to conventional blood and urine analyses, hair analysis can provide useful information on long-term drug exposure. Meta-bolite-to-drug (MD) ratios are helpful in interpreting hair results, as they provide useful information on drug metabolism and can be used to distinguish drug use from external contamination, which is otherwise a limitation in hair analysis. Despite this, the MD ratios of a wide range of pharmaceuticals have scarcely been explored. This review aims to provide an overview of MD ratios in hair in a range of pharmaceuticals of interest to forensic toxicology, such as antipsychotic drugs, antidepressant drugs, benzodiazepines, common opiates/opioids, etc. The factors influencing the ratio were evaluated. MD ratios of 41 pharmaceuticals were reported from almost 100 studies. MD ratios below 1 were frequently reported, indicating higher concentrations of the parent pharmaceutical than of its metabolite in hair, but wide-ranging MD ratios of the majority of pharmaceuticals were found. Intra- and interindividual differences and compound properties were variables possibly contributing to this. This overview presents guidance for future comparison and evaluation of MD ratios of pharmaceuticals.

Recent developments in sample preparation techniques combined with high-performance liquid chromatography: A critical review

This review article compares and contrasts sample preparation techniques coupled with high-performance liquid chromatography (HPLC) and describes applications developed in biomedical, forensics, and environmental/industrial hygiene in the last two decades. The proper sample preparation technique can offer valued data for a targeted application when coupled to HPLC and a suitable detector. Improvements in sample preparation techniques in the last two decades have resulted in efficient extraction, cleanup, and preconcentration in a single step, thus providing a pathway to tackle complex matrix applications. Applications such as biological therapeutics, proteomics, lipidomics, metabolomics, environmental/industrial hygiene, forensics, glycan cleanup, etc., have been significantly enhanced due to improved sample preparation techniques. This review looks at the early sample preparation techniques. Further, it describes eight sample preparation technique coupled to HPLC that has gained prominence in the last two decades. They are (1) solid-phase extraction (SPE), (2) liquid-liquid extraction (LLE), (3) gel permeation chromatography (GPC), (4) Quick Easy Cheap Effective Rugged, Safe (QuEChERS), (5) solid-phase microextraction (SPME), (6) ultrasonic-assisted solvent extraction (UASE), and (7) microwave-assisted solvent extraction (MWASE). SPE, LLE, GPC, QuEChERS, and SPME can be used offline and online with HPLC. UASE and MWASE can be used offline with HPLC but have also been combined with the online automated techniques of SPE, LLE, GPC, or QuEChERS for targeted analysis. Three application areas of biomedical, forensics, and environmental/industrial hygiene are reviewed for the eight sample preparation techniques. Three hundred and twenty references on the eight sample preparation techniques published over the last two decades (2001-2021) are provided. Other older references were included to illustrate the historical development of sample preparation techniques.

Determination of antidepressants and benzodiazepines in paired hair and nail samples

Hair and nails are keratinized matrices that can be used in Toxicology as matrices for the long-term detection of substances. Whereas hair is an established matrix with decades of use in this field, nails have been less studied, especially including a comparison to hair samples. Specifically in the case of antidepressant and benzodiazepine drugs, very few publications analyzing these drugs in nail samples exist as of yet. For this reason, in the present study a method for the detection of 12 antidepressant and benzodiazepine drugs in hair and nail samples was developed. Samples were decontaminated with 3 washes of dichloromethane, and 25 or 30 mg of hair and nails, respectively, were pulverized. Then, the samples were incubated with 1.5 mL water:ACN (50:50, v/v) with horizontal agitation for 90 min. The supernatant was evaporated and reconstituted in 200 µL of methanol and 2 mL of 2% FA in water, submitted to solid phase extraction (SPE) using Oasis MCX cartridges and analyzed by LC-MS/MS. The method was satisfactorily validated in nail and hair samples for the following parameters: linearity, LOD (0.005-0.02 ng/mg), LOQ (0.01-0.02 ng/mg), selectivity, carryover, accuracy, imprecision, matrix effect, extraction efficiency, process efficiency and autosampler stability. Matched fingernail, toenail and hair samples were obtained from 21 patients under treatment with any of the studied drugs and analyzed with the developed method. The most frequently detected drugs were venlafaxine (n = 11), trazodone (n = 6), zolpidem (n = 5), alprazolam (n = 5) and nordiazepam (n = 5). Concentrations in hair, fingernails and toenails, respectively, were 44.31 ng/mg, 8.05-43.35 ng/mg and 7.02-22.69 ng/mg for venlafaxine; 5.40-19.08 ng/mg, 0.13-1.00 ng/mg and 0.42-1.04 ng/mg for trazodone; 13.86 ng/mg, 5.19 ng/mg and 9.11 ng/mg for fluoxetine; 7.42 ng/mg, 1.85 ng/mg and 0.03-2.81 ng/mg for sertraline; 0.40-1.42 ng/mg, 0.12 ng/mg and 0.16 ng/mg for zolpidem; and 0.02-0.11 ng/mg, 0.07-1.07 ng/mg and 0.05 ng/mg for alprazolam for the patients under active treatment. Hair concentrations were higher than nail concentrations for most drugs in patients under active treatment, with the exception of diazepam (n = 1; 0.12 ng/mg in hair and 0.41 ng/mg in fingernails). Fingernail concentrations were lower than toenail concentrations in patients under active treatment in most compared cases. Comparison of fingernails and toenails of a patient with antifungal treatment did not show an observable effect in concentrations.

LC-MS/MS method for determining picogram-level of zolpidem and its main metabolites in hair using a zirconia-based sorbent

Although urine and blood samples have been conventionally used for testing zolpidem (ZPD), a sedative-hypnotic, these matrices have limited application because they have a relatively short detection period and can be used only in case of recent drug exposure. Therefore, it is necessary to use an alternative biological sample to obtain the evidence of ZPD misuse. Herein, a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of ZPD and its metabolites, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA), in hair to resolve the above-mentioned problems. Mechanical pulverization of hair, methanol extraction with sonication, and the zirconia-based hybrid solid-phase extraction technique were used for obtaining improved extraction efficiency and effective sample purification. The treated hair sample was analyzed using the LC-MS/MS method with the electrospray ionization source in positive and multiple-reaction monitoring modes. The target analytes were separated and detected within 8 min using an Xselect HSS T3 column. Gradient elution was performed using 5 mM ammonium formate and acetonitrile. The lower limit of quantification of ZPD, ZPCA, and ZCA were 1.0, 0.5, and 1.0 pg mg^-1, respectively. The calibration ranges were 1.0-1000.0 pg mg^-1 for ZPD, 0.5-200.0 pg mg^-1 for ZPCA, and 1.0-200.0 pg mg^-1 for ZCA, with the determination coefficients (r² ≥ 0.9986). The intraday accuracy and precision ranged from -7.1 to 9.0% and within 6.5%, respectively, and the interday accuracy and precision ranged from -6.1 to 7.9% and within 5.4%, respectively. The recovery, matrix effect, and process efficiency were 65.2-96.6%, 64.6-106.5%, and 44.3-100.5%, respectively, with the relative standard deviation of 4.0-5.0%. The developed method was successfully applied to analyze 13 forensic hair samples of ZPD abusers, and the concentration ratios of ZPD and its two main metabolites (ZPCA and ZCA) in the ZPD-positive samples were also presented. These results revealed that ZPCA and ZCA were not easily incorporated into hair, and demonstrated that their analysis in hair samples requires the employed method to have picogram-level sensitivity. Therefore, the developed method was suitable for simultaneous analysis of ZPD, ZPCA, and ZCA in hair samples, and it could provide clear evidence for illegal ZPD administration, including ZPD-facilitated sexual assault.

Group-Targeting SERS Screening of Total Benzodiazepines Based on Large-Size (111) Faceted Silver Nanosheets Decorated with Zinc Oxide Nanoparticles

Rapid, quantitative, and group-targeting detection of total benzodiazepines (BZDs) is critical to create an accurate judgement in emergent medical and forensic settings. Large-size (111) faceted Ag nanosheets decorated with small ZnO nanoparticles were designed as the prominent surface-enhanced Raman scattering substrate, which possessed advantages of specific metal facets and additional charge-transfer (CT) effect from the semiconductor. The vital and bridge role of ZnO in the CT effect was systematically studied via experimental investigations and molecular dynamics simulation, which proves the essentiality of an appropriate ZnO decoration density. Upon determining optimal Ag NS/ZnO hybrids, a calibration curve of estazolam was established with a 0.5 nM detection limit. Based on the obtained curve, group-targeting screening was achieved toward total concentrations of five BZDs (estazolam, oxazepam, alprazolam, triazolam, and lorazepam). Importantly, the total concentrations of BZDs in mice serum were accurately monitored with changing analytical time during the metabolic process, which was in agreement with the tendency measured by liquid chromatography with tandem mass spectrometry.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

In Vitro Interaction of AB-FUBINACA with Human Cytochrome P450, UDP-Glucuronosyltransferase Enzymes and Drug Transporters

AB-FUBINACA, a synthetic indazole carboxamide cannabinoid, has been used worldwide as a new psychoactive substance. Because drug abusers take various drugs concomitantly, it is necessary to explore potential AB-FUBINACA-induced drug–drug interactions caused by modulation of drug-metabolizing enzymes and transporters. In this study, the inhibitory effects of AB-FUBINACA on eight major human cytochrome P450s (CYPs) and six uridine 5′-diphospho-glucuronosyltransferases (UGTs) of human liver microsomes, and on eight clinically important transport activities including organic cation transporters (OCT)1 and OCT2, organic anion transporters (OAT)1 and OAT3, organic anion transporting polypeptide transporters (OATP)1B1 and OATP1B3, P-glycoprotein, and breast cancer resistance protein (BCRP) in transporter-overexpressing cells were investigated. AB-FUBINACA inhibited CYP2B6-mediated bupropion hydroxylation via mixed inhibition with K_i value of 15.0 µM and competitively inhibited CYP2C8-catalyzed amodiaquine N-de-ethylation, CYP2C9-catalyzed diclofenac 4′-hydroxylation, CYP2C19-catalyzed [S]-mephenytoin 4′-hydroxylation, and CYP2D6-catalyzed bufuralol 1′-hydroxylation with K_i values of 19.9, 13.1, 6.3, and 20.8 µM, respectively. AB-FUBINACA inhibited OCT2-mediated MPP⁺ uptake via mixed inhibition (K_i, 54.2 µM) and competitively inhibited OATP1B1-mediated estrone-3-sulfate uptake (K_i, 94.4 µM). However, AB-FUBINACA did not significantly inhibit CYP1A2, CYP2A6, CYP3A4, UGT1A1, UGT1A3, UGT1A4, UGT1A6, or UGT2B7 enzyme activities at concentrations up to 100 µM. AB-FUBINACA did not significantly inhibit the transport activities of OCT1, OAT1/3, OATP1B3, P-glycoprotein, or BCRP at concentrations up to 250 μM. As the pharmacokinetics of AB-FUBINACA in humans and animals remain unknown, it is necessary to clinically evaluate potential in vivo pharmacokinetic drug–drug interactions induced by AB-FUBINACA-mediated inhibition of CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, OCT2, and OATP1B1 activities.

In Vitro Inhibitory Effects of APINACA on Human Major Cytochrome P450, UDP-Glucuronosyltransferase Enzymes, and Drug Transporters

APINACA (known as AKB48, N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide), an indazole carboxamide synthetic cannabinoid, has been used worldwide as a new psychoactive substance. Drug abusers take various drugs concomitantly, and therefore, it is necessary to characterize the potential of APINACA-induced drug–drug interactions due to the modulation of drug-metabolizing enzymes and transporters. In this study, the inhibitory effects of APINACA on eight major human cytochrome P450s (CYPs) and six uridine 5′-diphospho-glucuronosyltransferases (UGTs) in human liver microsomes, as well as on the transport activities of six solute carrier transporters and two efflux transporters in transporter-overexpressed cells, were investigated. APINACA exhibited time-dependent inhibition of CYP3A4-mediated midazolam 1′-hydroxylation (K_i, 4.5 µM; k_inact, 0.04686 min⁻¹) and noncompetitive inhibition of UGT1A9-mediated mycophenolic acid glucuronidation (K_i, 5.9 µM). APINACA did not significantly inhibit the CYPs 1A2, 2A6, 2B6, 2C8/9/19, or 2D6 or the UGTs 1A1, 1A3, 1A4, 1A6, or 2B7 at concentrations up to 100 µM. APINACA did not significantly inhibit the transport activities of organic anion transporter (OAT)1, OAT3, organic anion transporting polypeptide (OATP)1B1, OATP1B3, organic cation transporter (OCT)1, OCT2, P-glycoprotein, or breast cancer resistance protein at concentrations up to 250 μM. These data suggest that APINACA can cause drug interactions in the clinic via the inhibition of CYP3A4 or UGT1A9 activities.