Application of a UPLC-MS/MS method for quantitative analysis of 29 synthetic cannabinoids and their metabolites, such as ADB-BUTINACA and MDMB-4en-PINACA in human hair in real cases

Establishment of Broad-Specificity Monoclonal Antibody-Based Immunoassay for Rapid Detection of Indole-Type and Indazole-Type Synthetic Cannabinoids and Metabolites

Synthetic cannabinoids (SCs) have emerged as one of the most severely abused categories of new psychoactive substances (NPS), exacerbating the global drug problem and posing significant threats to public health. Presently, a class of new amide-type SCs featuring an indazole or indole core has been identified in numerous cases of illegal drug use, but there is still a lack of comprehensive analysis methods of SC detection. Herein, monoclonal antibodies (mAbs) 2E4 and AE6 targeting 36 indole-type and indazole-type SCs and their metabolites with IC50 ranging from 0.14 to 85.28 ng/mL were prepared and the molecular mechanism of antibody recognition was elaborated. We established the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and gold immunochromatography assay (GICA) based on mAbs 2E4 and AE6 to detect indazole-type and indole-type SCs in urine and hair samples. Under optimal conditions, the proposed method detected ADB-BUTINACA (an indazole-type SC) with limits of detection (LODs) of 0.11 ng/mL for urine and 0.024 ng/mg for hair by ic-ELISA, and 1.02 ng/mL for urine and 0.046 ng/mg for hair by GICA; the LODs of 4F-MDMB-BUTICA (an indole-type SC) detection was 0.036 ng/mL for urine and 0.012 ng/mg for hair by ic-ELISA, and 0.54 ng/mL for urine and 0.03 ng/mg for hair by GICA. Collectively, our study provides a comprehensive foundation for the rapid screening and quantitation of SC derivatives in biological samples.

Detection of "smoke powder" etomidate and its metabolite etomidate acid in blood and urine by UHPLC-MS-MS: application in authentic cases

Recently, etomidate has been widely used as an alternative in illicit drug market. It is usually added to regular cigarette tobacco (commonly known as "cigarette powder") or mixed in e-cigarette oil sold through the Internet, retail stores, or entertainment outlets and other channels. An ultra-high performance liquid chromatography tandem mass spectrometry method was developed to quantify etomidate and etomidate acid in human blood and urine. The limit of detection (LOD) of etomidate and etomidate acid in blood is 0.5  and 2 ng/mL, respectively, and the lower limit of quantification (LLOQ) is 1  and 5 ng/mL, respectively. The LOD of etomidate and etomidate acid in urine is 1 and 2 ng/mL, respectively, and the LLOQ is 2  and 5 ng/mL, respectively. The precision, accuracy, recoveries, and matrix effects of etomidate and etomidate acid determinations in blood and urine met the requirements for methodological validation. The method was successfully applied to the identification and quantification of etomidate and etomidate acid in blood and urine of 62 forensic cases. The concentration of etomidate ranged from 1.52 to 8.41 ng/mL (positive cases, n = 5) and the concentration of etomidate acid ranged from 2.76 to 112 ng/mL (positive cases, n = 5) in blood. The concentrations of etomidate and etomidate acid in urine samples were 2.64-79,300 ng/mL (positive cases, n = 59) and 6.11-518,000 ng/mL (positive cases, n = 60), respectively. Therefore, the concentration of etomidate in blood and urine is mostly higher than that of etomidate.

How to trace etomidate in illegal E-cigarettes from authentic human hair: identification, quantification and multiple-factor analysis

PURPOSE

The abusive consumption of illegal E-cigarettes containing etomidate (ET) can have a significant impact on public mental and physical well-being. The purpose of this study is to establish a rapid quantitative method using ultra-high-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) for the targeted screening of etomidate (ET) and its metabolite etomidate acid (ETA) in hair samples.

METHODS

A 1 mL methanol solution containing the internal standard ET-d5 at a concentration of 50 pg/mg was added to 20 mg of hair and milled below 4 °C. After centrifugation, 5 μL of the supernatant was injected into a UHPLC-MS/MS system.

RESULTS

The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 1 pg/mg and 10 pg/mg, respectively, for ET, and 10 pg/mg and 25 pg/mg, respectively, for ETA. Calibration curves for all analytes showed good linearity (r > 0.997), indicating a reliable method. Accuracies were between 92.12% and 110.72%. Intra-day and inter-day precision for all analytes at all concentration levels were below 10.13%. Analyte recoveries ranged from 86.90% to 101.43%, with a matrix effect ranging from -18.55% to -14.93%.

CONCLUSIONS

The validated method was successfully used to analyze 105 hair samples from suspected ET users. Of these, 50 tested positive for ET and 43 tested positive for ETA above the LOQ. This demonstrates the effectiveness of the developed UHPLC-MS/MS method in detecting ET and ETA in hair samples, which could be instrumental in addressing the issue of illegal E-cigarette abuse and its impact on public health.

Detecting novel psychoactive substances around the world

PURPOSE OF REVIEW

The worldwide spread of novel psychoactive substances (NPS) in the illicit drug market and their continuous increase in number and type, for the purpose of bypassing controlled substance legislation, represents a continuing challenge for forensic scientists, clinicians and enforcement authorities. We aim to provide information regarding the most urgent harms related to NPS consumption in different world regions and the current state of the art for NPS analysis.

RECENT FINDINGS

Unfortunately, the identification of NPS in biological samples is controversial, especially when samples are limited, or the drug is promptly and extensively metabolized. This causes a lack of information on their real diffusion in different parts of the world and in different populations. New technologies and instrumental detection of NPS in alternative samples are offering comprehensive information about NPS use.

SUMMARY

The lack of detection and underreporting of NPS in biological samples makes it difficult to obtain complete qualitative and quantitative information about NPS prevalence. The most innovative strategies that have been proposed in the last 2 years to assist NPS analysis and possibly facilitate the understanding of the NPS diffusion around the world are presented.

Structure-Activity Relationships, Deuteration, and Fluorination of Synthetic Cannabinoid Receptor Agonists Related to AKB48, 5F-AKB-48, and AFUBIATA

Synthetic cannabinoid receptor agonists (SCRAs) are a growing class of new psychoactive substances (NPS) commonly derived from an N-alkylated indole, indazole, or 7-azaindole scaffold. Diversification of this core (at the 3-position) with amide-linked pendant amino acid groups and modular N-alkylation (of the indole/indazole/7-azaindole core) ensures that novel SCRAs continue to enter the illicit drug market rapidly. In response to the large number of SCRAs that have been detected, pharmacological evaluation of this NPS class has become increasingly common. Adamantane-derived SCRAs have consistently appeared throughout the market since 2011, and as such, a systematic set of these derivatives was synthesized and pharmacologically evaluated. Deuterated and fluorinated adamantane derivatives were prepared to evaluate typical hydrogen bioisosteres, as well as evaluation of the newly detected AFUBIATA.

Separation and Characterization of Synthetic Cannabinoid Metabolite Isomers Using SLIM High-Resolution Ion Mobility-Tandem Mass Spectrometry (HRIM-MS/MS)

Synthetic cannabinoids, a subclass of new psychoactive substances (NPS), are laboratory-made substances that are chemically similar to those found naturally in the cannabis plant. Many of these substances are illicitly manufactured and have been associated with severe health problems, prompting a need to develop analytical methods capable of characterizing both known and previously undetected compounds. This work focuses on a novel Structures for Lossless Ion Manipulations (SLIM) IM-MS approach to the differentiation and structural characterization of synthetic cannabinoid metabolites, specifically MDA-19/BUTINACA, JWH-018, and JWH-250 isomer groups. These different compound classes are structurally very similar, differing only in the position of one or a few functional groups; this yielded similarity in measured collision cross section (CCS) values. However, the high resolution of SLIM IM provided adequate separation of many of these isomers, such as sodiated JWH-250 metabolites N-4-OH, N-5-OH, and 5-OH, which displayed CCS of 187.5, 182.5, and 202.3 Å2, respectively. In challenging cases where baseline separation was precluded due to nearly identical CCS, such as for JWH-018 isomers, simple derivatization by dansyl chloride selectively reacted with the 6-OH compound to provide differentiation of all isomers using a combination of CCS and m/z. Finally, the opportunity to use this method for structural elucidation of unknowns was demonstrated by using SLIM IM mobility-aligned MS/MS fragmentation. Different MDA-19/BUTINACA isomers were first mobility separated and could then be individually activated, yielding unique fragments for both targeted identification and structural determination. Overall, the described SLIM IM-MS/MS workflow provides significant potential as a rapid screening tool for the characterization of emerging NPS such as synthetic cannabinoids and their metabolites.

A comprehensive LC-MS/MS method for simultaneous analysis of 65 synthetic cannabinoids in human hair samples and application to forensic investigations

Synthetic cannabinoids (SCs) represent a diverse class of new psychoactive substances characterized by extensive substance variety and severe abuse implications. The current situation of synthetic cannabinoid abuse in China is getting worse, with an increasing number of SC variants emerging. Therefore, it is imperative to improve synthetic cannabinoid detecting methods to align with the prevalent abuse situation in the region. In this study, a reliable and validated liquid chromatography-tandem mass spectrometry method was developed for the qualitative and quantitative analysis of 65 SC analogues in human hair samples. The validation results demonstrated satisfactory linearity (r ≥ 0.99) within the range of 25-2500 pg/mg for each SC analogue. The method exhibited limits of detection ranging from 10 to 15 pg/mg and limits of quantification ranging from 25 to 40 pg/mg. The relative standard deviations of intra-day precision and inter-day precision were below 15 %. Furthermore, negligible matrix effects were observed, with recovery rates ranging from 85.70 % to 119.43 %. Analysis of abuser demographics revealed that the primary group engaged in SC analogue abuse consisted of adolescents, predominantly males, accounting for 79.5 % of cases. Among the suspected individuals, ADB-BUTINACA and MDMB-4en-PINACA were the most frequently detected substances. The present study develops a highly sensitive analytical method and provides a comprehensive overview of the prevalence of SC abuse in the eastern region of China.

A new application of the switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction to analyze synthetic cannabinoids in plasma by LC-MS/MS

Synthetic cannabinoids are still a growing trend among drug users and consist of a group of hundreds of highly potent compounds. To investigate the use of such substances, sample preparation of biological matrices is a crucial step prior to instrumental analysis. Although different efficient extraction techniques have been proposed for that aim, they usually do not fit eco-friendly guidelines that have been gaining popularity in recent years, such as Green Analytical Toxicology. This work uses describes for the first time the use of switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction (SHS-HLLME) for synthetic cannabinoids. This is a green technique that replaces highly toxic organic reagents for switchable hydrophilicity solvents (SHS), substances that can be either water-miscible or immiscible depending on their protonation. Thus, by simply adjusting the pH of the system, these SHS can be used as extraction solvents. A full optimization study including type of SHS, volume of protonated SHS, volume of NaOH, salting-out effect, and extraction time was performed. The optimized procedure consisted of precipitating the proteins of 300 µL of plasma with 300 µL of acetonitrile followed by centrifugation; evaporation of the organic solvent under N2 stream; addition of 500 µL of the protonated DPA, DPA-HCl (6 M) (1:1, v/v); addition of 500 µL of NaOH (10 M); and finally centrifugation and evaporation. Validation results showed determination coefficients ≥ 0.99 for the 0.1-10 ng/mL linear range; 0.01-0.08 ng/mL as limit of detection; 0.1 ng/mL as limit of quantitation; accuracy and imprecision were within acceptable ranges; matrix effect, recovery, and process efficiency ranged from -55.6 to 185.9%, 36-56.7%, and 18.5-148.4%, respectively. The SHS-HLLME herein described was fully optimized providing satisfactory recoveries of 31 synthetic cannabinoids at low concentrations requiring only 300 µL of plasma. In addition, the validation results showed that the technique is a reliable eco-friendly alternative for clinical and toxicological analysis.

A comprehensive analytical strategy based on characteristic fragments to detect synthetic cannabinoid analogs in seized products and hair samples

Synthetic cannabinoids, one of the most widely abused new psychoactive substances (NPS), are now placed under national control generally in China. Due to continuous modification of synthetic cannabinoid structure, an ongoing dilemma in the forensic laboratory is that newly emerging substances cannot be detected by established methods. Thus, the screening methods for simultaneous detection of known or unknown substances have become research hotspots. In this study, the ultra high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-QqQ-MS) with precursor ion scan (PIS) as acquisition mode was used for prescreening purposes of all possible synthetic cannabinoids-related substances. In detail, four common characteristic fragments, m/z of 144.0, 145.0, 135.1, and 109.0 corresponding to acylium-indole, acylium-indazole, adamantyl, and fluorobenzyl cation respectively, were selected for PIS mode, and their collision energies were optimized by 97 available synthetic cannabinoids standards with relevant structures. Those suspicious signals observed in the screening experiment were confirmed by ultra high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) via high-resolution MS and MS² data obtained by full scan (TOF MS) and product ion scan mode. After methodological validation, the integrated strategy established above was applied to the screening and identification of the seized e-liquids, herbal blends and hair samples, confirming the presence of multiple synthetic cannabinoids in these samples. In particular, a novel synthetic cannabinoid was identified as 4 F-ABUTINACA, for which no relevant high-resolution mass spectrometry (HRMS) data has been retrieved until now, making this study the first to report the cleavage pattern of this compound in electrospray ionization (ESI) mass spectrometry. In addition, four other suspected by-products of the synthetic cannabinoids were found in the herbal blends and e-liquids, and their possible structures were also deduced via the information from high-resolution mass spectra.

Cannabinoids as multifaceted compounds

Since ancient times, Cannabis and its preparations have found various applications such as for medical, recreational and industrial purposes. Subsequently the 1930s, legislation in many countries has restricted its use due to its psychotropic properties. More recently, the discovery of endocannabinoid system, including new receptors, ligands, and mediators, its role in maintaining the homeostasis of the human body and the possible implication in various physiological and pathophysiological processes has also been understood. Based on this evidence, researchers were able to develop new therapeutic targets for the treatment of various pathological disorders. For this purpose, Cannabis and cannabinoids were subjected for the evaluation of their pharmacological activities. The renewed interest in the medical use of cannabis for its potential therapeutic application has prompted legislators to take action to regulate the safe use of cannabis and products containing cannabinoids. However, each country has an enormous heterogeneity in the regulation of laws. Here, we are pleased to show a general and prevailing overview of the findings regarding cannabinoids and the multiple research fields such as chemistry, phytochemistry, pharmacology and analytics in which they are involved.

Structural confirmation of synthetic cannabinoids in seized electronic cigarette oil: A combined mass spectrometric and computational study

RATIONALE

Synthetic cannabinoids are some of the most used and abused new psychoactive substances, because they can produce a stronger intense pleasure than natural cannabis. Most of the new synthetic cannabinoids are structurally similar to existing synthetic cannabinoids and can be obtained by modifying partial structures of the latter without changing their effects. Therefore, the derivatization rules and common fragmentation patterns of synthetic cannabinoids could be used for rapid screening and structural identification of them.

METHODS

The derivatization rules of synthetic cannabinoids are summarized, and the common fragmentation pattern of synthetic cannabinoids including three typical cleavage pathways was explored and extended in this work based on combined mass spectrometry (MS) and density functional theory studies. Five synthetic cannabinoids in electronic cigarette oil from a drug case were separated and characterized using gas chromatography with MS and liquid chromatography coupled to high-resolution quadrupole Orbitrap MS.

RESULTS

The structures of five synthetic cannabinoids in seized electronic cigarette oil were deduced from electron impact ion source (EI) MS and high-resolution electrospray ionization (ESI) MSⁿ data, along with the derivatization rules and common fragmentation pattern of synthetic cannabinoids. The proposed structures of these synthetic cannabinoids were further verified via reference substances. Computational study showed that selective cleavage of these compounds was mainly controlled by spin population in EI-MS, but a tunneling effect arose from proton transfer in ESI-MSⁿ detection, which has been rarely reported in previous works.

CONCLUSIONS

Our results showed that EI-MS was suitable for identifying synthetic cannabinoids with aromatic ketone structure, which could also be extended to adamantane linked group. Nevertheless, synthetic cannabinoids with carbamoyl linked group were better characterized by high-resolution ESI-MSⁿ compared to EI-MS. This study demonstrated a method with promising potential for rapid and reliable screening of synthetic cannabinoids in mixtures with enhanced detection throughput and operation simplicity.

Study of the Metabolic Profiles of "Indazole-3-Carboxamide" and "Isatin Acyl Hydrazone" (OXIZID) Synthetic Cannabinoids in a Human Liver Microsome Model Using UHPLC-QE Orbitrap MS

Unregulated core structures, "isatin acyl hydrazones" (OXIZIDs), have quietly appeared on the market since China legislated to ban seven general core scaffolds of synthetic cannabinoids (SCs). The fast evolution of SCs presents clinical and forensic toxicologists with challenges. Due to extensive metabolism, the parent compounds are barely detectable in urine. Therefore, studies on the metabolism of SCs are essential to facilitate their detection in biological matrices. The aim of the present study was to elucidate the metabolism of two cores, "indazole-3-carboxamide" (e.g., ADB-BUTINACA) and "isatin acyl hydrazone" (e.g., BZO-HEXOXIZID). The in vitro phase I and phase II metabolism of these six SCs was investigated by incubating 10 mg/mL pooled human liver microsomes with co-substrates for 3 h at 37 °C, and then analyzing the reaction mixture using ultrahigh-performance liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry. In total, 9 to 34 metabolites were detected for each SC, and the major biotransformations were hydroxylation, dihydrodiol formation (MDMB-4en-PINACA and BZO-4en-POXIZID), oxidative defluorination (5-fluoro BZO-POXIZID), hydrogenation, hydrolysis, dehydrogenation, oxidate transformation to ketone and carboxylate, N-dealkylation, and glucuronidation. Comparing our results with previous studies, the parent drugs and SC metabolites formed via hydrogenation, carboxylation, ketone formation, and oxidative defluorination were identified as suitable biomarkers.

Determination of 5 synthetic cannabinoids in hair by Segmental analysis using UHPLC-MS/MS and its application to eight polydrug abuse cases

In recent years, an increasing number of new synthetic cannabinoids (SCs) have appeared in the drug trade market. A UPLC-MS/MS method was developed to simultaneously identify five synthetic cannabinoids in 1 cm segment hair samples. The method was fully validated and confirmed to have good selectivity, accuracy, and precision, as well as satisfactory linearity within the calibrated range. The limit of quantification (LOD) was 0.5 pg/mg, and the lower limit of quantitation (LLOQ) was 1 pg/mg, with intraday and interday accuracies (bias) ranging from - 9.6-13.7%. The validated method was successfully used for qualitative and quantitative analysis of five SCs in authentic hair samples of eight SC abusers. SCs were detected in 8 cases at concentrations ranging from 1.5 to 632.9 pg/mg.

Quantification of MDMB-4en-PINACA and ADB-BUTINACA in human hair by gas chromatography-tandem mass spectrometry

PURPOSE

To test synthetic cannabinoid (SCs) in parent forms from living human, the hairs seems to be one of the best samples, because of the non-invasiveness upon their collection. The purpose of this study is to establish a method for quantification of MDMB-4en-PINACA and ADB-BUTINACA, the most recently abused SCs in hair samples, using gas chromatography-tandem mass spectrometry (GC-MS/MS).

METHODS

The collected hair samples were washed with a detergent solution, following by water and acetone. After drying cutting them into about 2 mm sections, they were ground by a cryogenic grinder into powder. The 50-mg powder with internal standard(s) plus 1 mL methanol were vortexed, and centrifuged to obtain the supernatant layer. After its evaporation and reconstitution with 50 µL methanol, 1-µL aliquot of it was subjected to analysis.

RESULTS

The standard calibration curves were created for both MDMB-4en-PINACA and ADB-BUTINACA in blank hair samples; good linear curves were obtained in the range of 20-20,000 pg/mg with correlation coefficients greater than 0.99. The limits of detection and limits of quantification were 10 and 20 pg/mg, respectively. Other validation parameters were all satisfactory. The concentrations of MDMB-4en-PINACA obtained from 3 authentic subjects and ADB-BUTINACA obtained from 3 authentic subjects were 26.2-806 pg/mg and 63.1-430 pg/mg, respectively.

CONCLUSIONS

In the present article, the details of simple and rapid quantification of MDMB-4en-PINACA and ADB-BUTINACA in human scalp hair have been established. To our knowledge, this is the first report for quantification of SCs in hair samples by GC-MS/MS.

Detection of the Synthetic Cannabinoids AB-CHMINACA, ADB-CHMINACA, MDMB-CHMICA, and 5F-MDMB-PINACA in Biological Matrices: A Systematic Review

Simple Summary

Synthetic cannabinoids were originally developed for scientific research and potential therapeutic agents. However, clandestine laboratories synthesize them and circumvent legal barriers by falsely marketing them as incense or herbal products. They have serious adverse effects, and new derivatives are continuously found in the market, making their detection difficult due to the lack of comparative standards. Human matrices are used to identify the type of synthetic cannabinoid and the time of its consumption. This review discusses the use of hair, oral fluid, blood, and urine in the detection and quantification of some of the major synthetic cannabinoids. Based on the results, some recommendations can be followed, for example, the use of hair to detect chronic and retrospective consumption (although sensitive to external contamination) and oral fluid or blood for the simultaneous detection of the parent compounds and their metabolites. If longer detection times than blood or oral fluid are needed, urine is the matrix of choice, although its pH may intervene in the analysis. This work highlights the use of new techniques, such as high-resolution mass spectrometry, to avoid the use of previous standards and to monitor new trends in the drug market.

Abstract

New synthetic cannabinoids (SCs) are emerging rapidly and continuously. Biological matrices are key for their precise detection to link toxicity and symptoms to each compound and concentration and ascertain consumption trends. The objective of this study was to determine the best human biological matrices to detect the risk-assessed compounds provided by The European Monitoring Centre for Drugs and Drug Addiction: AB-CHMINACA, ADB-CHMNACA, MDMB-CHMICA, and 5F-MDMB-PINACA. We carried out a systematic review covering 2015 up to the present date, including original articles assessing detection in antemortem human biological matrices with detailed validation information of the technique. In oral fluid and blood, SC parent compounds were found in oral fluid and blood at low concentrations and usually with other substances; thus, the correlation between SCs concentrations and severity of symptoms could rarely be established. When hair is used as the biological matrix, there are difficulties in excluding passive contamination when evaluating chronic consumption. Detection of metabolites in urine is complex because it requires prior identification studies. LC-MS/MS assays were the most widely used approaches for the selective identification of SCs, although the lack of standard references and the need for revalidation with the continuous emergence of new SCs are limiting factors of this technique. A potential solution is high-resolution mass spectrometry screening, which allows for non-targeted detection and retrospective data interrogation.