Detection of the recently emerged synthetic cannabinoid 4F‐MDMB‐BINACA in “legal high” products and human urine specimens

Synthetic cannabinoids (SCs) remain one of the largest groups of new psychoactive substances (NPS) on the European drug market. Although the number of new derivatives occurring on the market has dropped in the last two years, newly emerging NPS still represent a challenge for laboratories performing forensic drug analysis in biological matrices. The newly emerged SC 4F‐MDMB‐BINACA has been reported by several law enforcement agencies in Europe and the USA since November 2018. This work aimed at revealing urinary markers to prove uptake of 4F‐MDMB‐BINACA and differentiate from the use of structurally similar SCs. Phase‐I metabolites detected in human urine specimens were confirmed by phase‐I metabolites generated in vitro using a pooled human liver microsomes (pHLM) assay. Seized materials and test‐purchased “legal high” products were analyzed by gas chromatography–mass spectrometry (GC–MS) and liquid chromatography?quadrupole‐time‐of‐flight?mass spectrometry (LC?qToF?MS). Human urine specimens and pHLM assay extracts were measured with liquid chromatography?electrospray ionization?tandem mass spectrometry (LC?ESI?MS/MS) and confirmed by LC?qToF?MS. In January 2019, the Institute of Legal Medicine in Erlangen (Germany) identified 4F‐MDMB‐BINACA in three herbal blends. During the same time period, the described SC was identified in a research chemical purchased online. Investigation of phase‐I metabolism led to the metabolites M10 (ester hydrolysis) and M11 (ester hydrolysis and dehydrogenation) as reliable urinary markers. Widespread distribution on the German drug market was proven by analysis of urine samples from abstinence control programs and by frequent detection of 4F‐MDMB‐BINACA in “herbal blends” and “‘research chemicals” purchased via the Internet.     

Simultaneous analysis of 29 synthetic cannabinoids and metabolites,amphetamines, and cannabinoids in human whole blood by liquid chromatography–tandem mass spectrometry – A New Zealand perspective of use in 2018

We describe the validation of a method for the simultaneous analysis of 29 synthetic cannabinoids (SCs) and metabolites, 4 amphetamines, and 2 cannabinoids in human whole blood. This method enables one analysis to cover what previously required multiple analyses for these classic and novel drugs‐of‐abuse with diverse physicochemical properties. The scope of targeted analytes was based on the most prevalent drugs‐of‐abuse and SCs encountered at the New Zealand border in 2017 and included parent compounds and metabolites belonging to the indole and indazole carboxamide, quinolinyl indole carboxylate, and naphthoylindole classifications. Samples were prepared by supported‐liquid‐extraction (SLE) followed by liquid chromatography?tandem mass spectrometry (LC?MS/MS) analysis with positive electrospray ionization (ESI). The method was validated with respect to selectivity, matrix effects, process efficiency, sensitivity, repeatability, extract stability, and carryover for qualitative confirmation. Linearity as well as accuracy and precision data at target decision concentrations were also evaluated. The limits of detection and confirmation ranged from 0.1 to 6.0 ng/mL and 1.0 to 6.0 ng/mL, respectively. The described method was successfully applied to the analysis of 564 ante‐ and post‐mortem blood samples in 2018. There were 132 cases (23%) with positive findings of at least one SC, with the five most commonly detected SCs being AMB‐FUBINACA and/or acid (61%), 5F‐ADB and/or acid (40%), ADB‐FUBINACA (11%), 5F‐MDMB‐PICA acid (6%), and MDMB‐FUBINACA acid (6%). The results also demonstrate the predominant presence of metabolites at higher levels than the unchanged parent SCs in blood, highlighting the need to maintain forensic screening methods capable of the simultaneous detection of both parent compounds and metabolites.     

Solid‐phase extraction–liquid chromatography–tandem mass spectrometry method for the qualitative analysis of 61 synthetic cannabinoid metabolites in urine

This article comprises the development and validation of a protocol for the qualitative analysis of 61 phase I synthetic cannabinoid metabolites in urine originating from 29 synthetic cannabinoids, combining solid‐phase extraction (SPE) utilizing a reversed phase silica‐based sorbent (phenyl) with liquid chromatography–tandem mass spectrometry (LC?MS/MS). Validation was performed according to the guidelines of the German Society of Toxicological and Forensic Chemistry. Sufficient chromatographic separation was achieved within a total runtime of 12.3 minutes. Validation included specificity and selectivity, limit of detection (LOD), recovery and matrix effects, as well as auto‐sampler stability of processed urine samples. LOD ranged between 0.025 ng/mL and 0.5 ng/mL in urine. Recovery ranged between 43% and 97%, with only two analytes exhibiting recoveries below 50%. However, for those two analytes, the LODs were 0.05 ng/mL in urine. In addition, matrix effects between 81% and 185% were determined, whereby matrix effects over 125% were observed for 10 non‐first‐generation synthetic cannabinoid metabolites. The developed method enables the rapid and sensitive detection of synthetic cannabinoid metabolites in urine, complementing the spectrum of existing analytical tools in forensic case work. Finally, application to 61 urine samples from both routine and autopsy case work yielded one urine sample that tested positive for ADB‐PINACA N‐pentanoic acid.     

Sulfate metabolites as alternative markers for the detection of 4‐chlorometandienone misuse in doping control

Sulfate metabolites have been described as long‐term metabolites for some anabolic androgenic steroids (AAS). 4‐chlorometandienone (4Cl‐MTD) is one of the most frequently detected AAS in sports drug testing and it is commonly detected by monitoring metabolites excreted free or conjugated with glucuronic acid. Sulfation reactions of 4Cl‐MTD have not been studied. The aim of this work was to evaluate the sulfate fraction of 4Cl‐MTD metabolism by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) to establish potential long‐term metabolites valuable for doping control purposes. 4Cl‐MTD was administered to two healthy male volunteers and urine samples were collected up to 8 days after administration. A theoretical selected reaction monitoring (SRM) method working in negative mode was developed. Ion transitions were based on ionization and fragmentation behaviour of sulfate metabolites as well as specific neutral losses (NL of 15 Da and NL of 36 Da) of compounds with related chemical structure. Six sulfate metabolites were detected after the analysis of excretion study samples. Three of the identified metabolites were characterized by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) and gas chromatography‐tandem mass spectrometry (GC‐MS/MS). Results showed that five out of the six identified sulfate metabolites were detected in urine up to the last collected samples from both excretion studies. Copyright © 2016 John Wiley & Sons, Ltd.     

Direct and efficient liquid chromatographic‐tandem mass spectrometric method for opiates in urine drug testing – importance of 6‐acetylmorphine and reduction of analytes

Opiates comprise a class of abused drugs that is of primary interest in clinical and forensic urine drug testing. Determination of heroin, codeine, or a multi‐drug ingestion is complicated since both heroin and codeine can lead to urinary excretion of free and conjugated morphine. Liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) offers advantage over gas chromatography‐mass spectrometry by simplifying sample preparation but increases the number of analytes. A method based on direct injection of five‐fold diluted urine for confirmation of morphine, morphine‐3‐glucuronide, morphine‐6‐glucuronide, codeine, codeine‐6‐glucuronide and 6‐acetylmorphine was validated using LC‐MS/MS in positive electrospray mode monitoring two transitions using selected reaction monitoring. The method was applied for the analysis of 3155 unknown urine samples which were positive for opiates in immunochemical screening. A linear response was observed for all compounds in the calibration curves covering more than three orders of magnitude. Cut off was set to 2 ng/ml for 6‐acetylmorphine and 150 ng/ml for the other analytes. 6‐Acetylmorphine was found to be effective (sensitivity 82%) in detecting samples as heroin intake. Morphine‐3‐glucuronide and codeine‐6‐glucuronide was the predominant components of total morphine and codeine, 84% and 93%, respectively. The authors have validated a robust LC‐MS/MS method for rapid qualitative and quantitative analysis of opiates in urine. 6‐Acetylmorphine has been demonstrated as a sensitive and important parameter for a heroin intake. A possible interpretation strategy to conclude the source of detected analytes was proposed. The method might be further developed by reducing the number of analytes to morphine‐3‐glucuronide, codeine‐6‐glucuronide and 6‐acetylmorphine without compromising test performance. Copyright © 2013 John Wiley & Sons, Ltd.     

Urinary detection of conjugated and unconjugated anabolic steroids by dilute‐and‐shoot liquid chromatography‐high resolution mass spectrometry

Anabolic androgenic steroids (AAS) are an important class of doping agents. The metabolism of these substances is generally very extensive and includes phase‐I and phase‐II pathways. In this work, a comprehensive detection of these metabolites is described using a 2‐fold dilution of urine and subsequent analysis by liquid chromatography‐high resolution mass spectrometry (LC‐HRMS). The method was applied to study 32 different metabolites, excreted free or conjugated (glucuronide or sulfate), which permit the detection of misuse of at least 21 anabolic steroids. The method has been fully validated for 21 target compounds (8 glucuronide, 1 sulfate and 12 free steroids) and 18 out of 21 compounds had detection limits in the range of 1–10 ng mL^?1 in urine. For the conjugated compounds, for which no reference standards are available, metabolites were synthesized in vitro or excretion studies were investigated. The detection limits for these compounds ranged between 0.5 and 18 ng mL^?1 in urine. The simple and straightforward methodology complements the traditional methods based on hydrolysis, liquid‐liquid extraction, derivatization and analysis by gas chromatography–mass spectrometry (GC‐MS) and liquid chromatography‐mass spectrometry (LC‐MS). Copyright © 2014 John Wiley & Sons, Ltd.     

Doping control analysis of four JWH‐250 metabolites in equine urine by liquid chromatography–tandem mass spectrometry

JWH‐250 is a synthetic cannabinoid. Its use is prohibited in equine sport according to the Association of Racing Commissioners International (ARCI) and the Fédération Équestre Internationale (FEI). A doping control method to confirm the presence of four JWH‐250 metabolites (JWH‐250 4‐OH‐pentyl, JWH‐250 5‐OH‐pentyl, JWH‐250 5‐OH‐indole, and JWH‐250 N‐pentanoic acid) in equine urine was developed and validated. Urine samples were treated with acetonitrile and evaporated to concentrate the analytes prior to the analysis by liquid chromatography–tandem mass spectrometry (LC–MS/MS). The chromatographic separation was carried out using a Phenomenex Lux^® 3 μm AMP column (150 x 3.0 mm). A triple quadrupole mass spectrometer was used for detection of the analytes in positive mode electrospray ionization using multiple reaction monitoring (MRM). The limits of detection, quantification, and confirmation for these metabolites were 25, 50, and 50 pg/mL, respectively. The linear dynamic range of quantification was 50–10000 pg/mL. Enzymatic hydrolysis indicated that JWH‐250 4‐OH‐pentyl, JWH‐250 5‐OH‐pentyl, and JWH‐250 5‐OH indole are highly conjugated whereas JWH‐250 N‐pentanoic acid is not conjugated. Relative retention time and product ion intensity ratios were employed as the criteria to confirm the presence of these metabolites in equine urine. The method was successfully applied to post‐race urine samples collected from horses suspected of being exposed to JWH‐250. All four JWH‐250 metabolites were confirmed in these samples, demonstrating the method applicability for equine doping control analysis.     

Fatal intoxication by 5F–ADB and diphenidine: Detection,quantification, and investigation of their main metabolic pathways in humans by LC/MS/MS and LC/Q‐TOFMS

Despite the implementation of a new blanket scheduling system in 2013, new psychoactive substance (NPS) abuse remains a serious social concern in Japan. We present a fatal intoxication case involving 5F–ADB (methyl 2‐[1‐(5‐fluoropentyl)‐1H–indazole‐3‐carboxamido]‐3,3‐dimethylbutanoate) and diphenidine. Postmortem blood screening by liquid chromatography/quadrupole time‐of‐flight mass spectrometry (LC/Q‐TOFMS) in the information‐dependent acquisition mode only detected diphenidine. Further urinary screening using an in‐house database containing NPS and metabolites detected not only diphenidine but also possible 5F–ADB metabolites; subsequent targeted screening by LC/tandem mass spectrometry (LC/MS/MS) allowed for the detection of a very low level of unchanged 5F–ADB in postmortem heart blood. Quantification by standard addition resulted in the postmortem blood concentrations being 0.19 ± 0.04 ng/mL for 5F–ADB and 12 ± 2.6 ng/mL for diphenidine. Investigation of the urinary metabolites revealed pathways involving ester hydrolysis (M1) and oxidative defluorination (M2), and further oxidation to the carboxylic acid (M3) for 5F–ADB. Mono‐ and di‐hydroxylated diphenidine metabolites were also found. The present case demonstrates the importance of urinary metabolite screening for drugs with low blood concentration. Synthetic cannabinoids (SCs) fluorinated at the terminal N‐alkyl position are known to show higher cannabinoid receptor affinity relative to their non‐fluorinated analogues; 5F–ADB is no exception with high CB₁ receptor activity and much greater potency than Δ⁹‐THC and other earlier SCs, thus we suspect its acute toxicity to be high compared to other structurally related SC analogues. The low blood concentration of 5F–ADB may be attributed to enzymatic and/or non‐enzymatic degradation, and further investigation into these possibilities is underway.     

Liquid chromatography‐quadrupole‐time‐of‐flight mass spectrometry screening procedure for urine samples in forensic casework compared to gas chromatography‐mass spectrometry

This work represents the development, validation, and application of a liquid chromatography‐quadrupole‐time‐of‐flight mass spectrometry (LC‐QTOF‐MS) screening method for the detection of pharmaceutical substances and illicit drugs (acidic, basic, and neutral organic drugs) in urine samples. Time‐of‐flight mass spectrometry was performed using an LC‐Triple TOF 5600 system with electrospray ionization operated in both positive and negative mode, respectively. The limits of detection (LODs), determined for 34 substances, were < 10 ng/mL for 91% of the compounds. The limits of quantitation (LOQs) were < 20 ng/mL for 91% of the substances. The identification of the compounds was based on exact mass (< ± 5 ppm), retention time (<2%) if available, isotopic pattern fit (<10%) and library hit (>70%). These four parameters served as identification criteria and are discussed according to their role in identifying compounds even without reference substances. In routine casework, two in‐house XIC (extracted ion chromatogram) lists, consisting of 456 protonated and 26 deprotonated compounds were used and retention times for 365 compounds were available. Compared to the results found with the established gas chromatography‐mass spectrometry (GC‐MS) procedure, the findings with the LC‐QTOF‐MS screening method showed a good comparability. Results that were not detected by LC‐QTOF‐MS because of a missing entry in the targeted XIC list could retrospectively be confirmed by simply entering the elemental formula of the relevant substance into the software and reprocessing the sample. LC‐QTOF‐MS offers an attractive technique for the fast and specific identification of illicit drugs and toxic compounds in urine samples. Copyright © 2016 John Wiley & Sons, Ltd.     

Phase I metabolism of the highly potent synthetic cannabinoid MDMB‐CHMICA and detection in human urine samples

Among the recently emerged synthetic cannabinoids, MDMB‐CHMICA (methyl N ‐{[1‐(cyclohexylmethyl)‐1H ‐indol‐3‐yl]carbonyl}‐3‐methylvalinate) shows an extraordinarily high prevalence in intoxication cases, necessitating analytical methods capable of detecting drug uptake. In this study, the in vivo phase I metabolism of MDMB‐CHMICA was investigated using liquid chromatography‐electrospray ionization‐tandem mass spectrometry (LC‐ESI‐MS/MS) and liquid chromatography‐electrospray ionization‐quadrupole time‐of‐flight‐mass spectrometry (LC‐ESI‐Q ToF‐MS) techniques. The main metabolites are formed by hydrolysis of the methyl ester and oxidation of the cyclohexyl methyl side chain. One monohydroxylated metabolite, the ester hydrolysis product and two further hydroxylated metabolites of the ester hydrolysis product are suggested as suitable targets for a selective and sensitive detection in urine. All detected in vivo metabolites could be verified in vitro using a human liver microsome assay. Two of the postulated main metabolites were successfully included in a comprehensive LC‐ESI‐MS/MS screening method for synthetic cannabinoid metabolites. The screening of 5717 authentic urine samples resulted in 818 cases of confirmed MDMB‐CHMICA consumption (14%). Since the most common route of administration is smoking, smoke condensates were analyzed to identify relevant thermal degradation products. Pyrolytic cleavage of the methyl ester and amide bond led to degradation products which were also formed metabolically. This is particularly important in hair analysis, where detection of metabolites is commonly considered a proof of consumption. In addition, intrinsic activity of MDMB‐CHMICA at the CB₁ receptor was determined applying a cAMP accumulation assay and showed that the compound is a potent full agonist. Based on the collected data, an enhanced interpretation of analytical findings in urine and hair is facilitated. Copyright © 2016 John Wiley & Sons, Ltd.     

Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines: An update comprising flunitrazolam,norflurazepam, and 4'‐chlorodiazepam (Ro5–4864)

The number of newly appearing benzodiazepine derivatives on the new psychoactive substances (NPS) drug market has increased over the last couple of years totaling 23 ‘designer benzodiazepines’ monitored at the end of 2017 by the European Monitoring Centre for Drugs and Drug Addiction. In the present study, three benzodiazepines [flunitrazolam, norflurazepam, and 4′‐chlorodiazepam (Ro5–4864)] offered as ‘research chemicals' on the Internet were characterized and their main in vitro phase I metabolites tentatively identified after incubation with pooled human liver microsomes. For all compounds, the structural formula declared by the vendor was confirmed by gas chromatography?mass spectrometry (GC–MS), liquid chromatography?tandem mass spectrometry (LC MS/MS), liquid chromatography?quadrupole time of flight?mass spectrometry (LC?QTOF?MS) analysis and nuclear magnetic resonance (NMR) spectroscopy. The metabolic steps of flunitrazolam were monohydroxylation, dihydroxylation, and reduction of the nitro function. The detected in vitro phase I metabolites of norflurazepam were hydroxynorflurazepam and dihydroxynorflurazepam. 4’‐Chlorodiazepam biotransformation consisted of N‐dealkylation and hydroxylation. It has to be noted that 4′‐chlorodiazepam and its metabolites show almost identical LC–MS/MS fragmentation patterns to diclazepam and its metabolites (delorazepam, lormetazepam, and lorazepam), making a sufficient chromatographic separation inevitable. Sale of norflurazepam, the metabolite of the prescribed benzodiazepines flurazepam and fludiazepam, presents the risk of incorrect interpretation of analytical findings.     

A rapid screening LC‐MS/MS method based on conventional HPLC pumps for the analysis of low molecular weight xenobiotics: application to doping control analysis

This study presents a fast multi‐analyte screening method specifically developed for the detection of xenobiotics in urine. The proposed method allows the screening of several classes of substance in a single chromatographic method with a run‐time of 11 min, inclusive of post‐run and reconditioning times. Chromatographic separation is achieved in 7.2 min using a reversed‐phase 2.7 µm fused‐core particle column, generating a back‐pressure not exceeding 400 bar and therefore enabling the use of traditional high performance liquid chromatography (HPLC) instruments. The effectiveness of this approach was evaluated, by liquid‐chromatography tandem mass spectrometry (LC‐MS/MS) in positive electrospray ionization, using 20 blank urine samples spiked with 45 compounds prohibited in sport: 11 diuretics, 16 glucocorticoids, 9 stimulants, 5 anti‐oestrogens, as well as formoterol, carboxy‐finasteride (previously prohibited by the World Anti‐Doping Agency (WADA) in 2008), gestrinone and tetrahydrogestrinone. Qualitative validation shows the proposed method to be specific with no significant interference. All of the analytes considered in this study were clearly distinguishable in urine, with limits of detection ranging from 5 ng/mL to 350 ng/mL, significantly below the Minimum Required Performance Levels (MRPL) set by WADA for the accredited sports anti‐doping laboratories. All compounds of interest were separated, including synthetic and endogenous glucocorticoids with similar retention times and fragmentation patterns. Copyright © 2010 John Wiley & Sons, Ltd.     

Phenethylamine‐derived new psychoactive substances 2C‐E‐FLY, 2C‐EF‐FLY,and 2C‐T‐7‐FLY: Investigations on their metabolic fate including isoenzyme activities and their toxicological detectability in urine screenings

Psychoactive substances of the 2C‐series are phenethylamine‐based designer drugs that can induce psychostimulant and hallucinogenic effects. The so‐called 2C‐FLY series contains rigidified methoxy groups integrated in a 2,3,6,7‐tetrahydrobenzo[1,2‐b:4,5‐b']difuran core. The aim of the presented work was to investigate the in vivo and in vitro metabolic fate including isoenzyme activities and toxicological detectability of the three new psychoactive substances (NPS) 2C‐E‐FLY, 2C‐EF‐FLY, and 2C‐T‐7‐FLY to allow clinical and forensic toxicologists the identification of these novel compounds. Rat urine, after oral administration, and pooled human liver S9 fraction (pS9) incubations were analyzed by liquid chromatography?high‐resolution tandem mass spectrometry (LC?HRMS/MS). By performing activity screenings, the human isoenzymes involved were identified and toxicological detectability in rat urine investigated using standard urine screening approaches (SUSAs) based on gas chromatography (GC)?MS, LC?MSⁿ, and LC?HRMS/MS. In total, 32 metabolites were tentatively identified. Main metabolic steps consisted of hydroxylation and N‐acetylation. Phase I metabolic reactions were catalyzed by CYP2D6, 3A4, and FMO3 and N‐acetylation by NAT1 and NAT2. Methoxyamine was used as a trapping agent for detection of the deaminated metabolite formed by MAO‐A and B. Interindividual differences in the metabolism of the 2C‐FLY drugs could be caused by polymorphisms of enzymes involved or drug–drug interactions. All three SUSAs were shown to be suitable to detect an intake of these NPS but common metabolites of 2C‐E‐FLY and 2C‐EF‐FLY have to be considered during interpretation of analytical findings.     

Metabolism of the tryptamine‐derived new psychoactive substances 5‐MeO‐2‐Me‐DALT, 5‐MeO‐2‐Me‐ALCHT,and 5‐MeO‐2‐Me‐DIPT and their detectability in urine studied by GC–MS,LC–MSn,and LC‐HR‐MS/MS

Many N,N‐dialkylated tryptamines show psychoactive properties and were encountered as new psychoactive substances. The aims of the presented work were to study the phase I and II metabolism and the detectability in standard urine screening approaches (SUSA) of 5‐methoxy‐2‐methyl‐N,N‐diallyltryptamine (5‐MeO‐2‐Me‐DALT), 5‐methoxy‐2‐methyl‐N‐allyl‐N‐cyclohexyltryptamine (5‐MeO‐2‐Me‐ALCHT), and 5‐methoxy‐2‐methyl‐N,N‐diisopropyltryptamine (5‐MeO‐2‐Me‐DIPT) using gas chromatography–mass spectrometry (GC–MS), liquid chromatography coupled with multistage accurate mass spectrometry (LC–MSⁿ), and liquid chromatography‐high‐resolution tandem mass spectrometry (LC‐HR‐MS/MS). For metabolism studies, urine was collected over a 24 h period after administration of the compounds to male Wistar rats at 20 mg/kg body weight (BW). Phase I and II metabolites were identified after urine precipitation with acetonitrile by LC‐HR‐MS/MS. 5‐MeO‐2‐Me‐DALT (24 phase I and 12 phase II metabolites), 5‐MeO‐2‐Me‐ALCHT (24 phase I and 14 phase II metabolites), and 5‐MeO‐2‐Me‐DIPT (20 phase I and 11 phase II metabolites) were mainly metabolized by O‐demethylation, hydroxylation, N‐dealkylation, and combinations of them as well as by glucuronidation and sulfation of phase I metabolites. Incubations with mixtures of pooled human liver microsomes and cytosols (pHLM and pHLC) confirmed that the main metabolic reactions in humans and rats might be identical. Furthermore, initial CYP activity screenings revealed that CYP1A2, CYP2C19, CYP2D6, and CYP3A4 were involved in hydroxylation, CYP2C19 and CYP2D6 in O‐demethylation, and CYP2C19, CYP2D6, and CYP3A4 in N‐dealkylation. For SUSAs, GC–MS, LC‐MSⁿ, and LC‐HR‐MS/MS were applied to rat urine samples after 1 or 0.1 mg/kg BW doses, respectively. In contrast to the GC–MS SUSA, both LC–MS SUSAs were able to detect an intake of 5‐MeO‐2‐Me‐ALCHT and 5‐MeO‐2‐Me‐DIPT via their metabolites following 1 mg/kg BW administrations and 5‐MeO‐2‐Me‐DALT following 0.1 mg/kg BW dosage. Copyright © 2017 John Wiley & Sons, Ltd.     

Analysis of new psychoactive substances in oral fluids by means of microextraction by packed sorbent followed by ultra‐high‐performance liquid chromatography–tandem mass spectrometry

In recent years, new drugs, commonly known as new psychoactive substances (NPS), appeared on the market, which include, among others, synthetic cannabinoids, cathinones, and tryptamine analogs of psilocin. The aim of this work was to develop and validate a new method for simultaneous screening and quantification of 31 NPS in oral fluid by ultra‐high‐performance liquid chromatography‐tandem mass spectrometry (UHPLC–MS/MS). The chosen target analytes represented different chemical and toxicological NPS classes, such as synthetic cathinones, piperazines, phenethylamines, synthetic cannabinoids, and their metabolites. The procedure involved a rapid sample preparation based on protein precipitation followed by clean‐up utilizing microextraction by packed sorbent (MEPS); the quantitative analysis was performed by UHPLC–MS/MS. The MEPS clean‐up, regardless of non‐quantitative recoveries for some analytes, provided an effective removal of interfering compounds, as demonstrated by reduced matrix effects found at different concentrations for all the analytes. The validation protocol, based on SWGTOX guidelines, demonstrated the suitability of the proposed method for quantitative analysis: linearity range ranged over 3 or 4 orders of magnitude; precision and accuracy tests gave RSD% values below 25%, and accuracy ranged from 85.9% to 107%, accomplishing SWGTOX requirements. Limits of detection (LODs) ranged between 0.005 ng/mL and 0.850 ng/mL and limits of quantification (LOQs) from 0.015 to 2.600 ng/mL.     

Detection and phase I metabolism of the 7‐azaindole‐derived synthetic cannabinoid 5F‐AB‐P7AICA including a preliminary pharmacokinetic evaluation

In June 2018, a 'research chemica'l labeled 'AB‐FUB7AICA' was purchased online and analytically identified as 5F‐AB‐P7AICA, the 7‐azaindole analog of 5F‐AB‐PINACA. Here we present data on structural characterization, suitable urinary consumption markers, and preliminary pharmacokinetic data. Structure characterization was performed by nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry, infrared and Raman spectroscopy. Phase I metabolites were generated by applying a pooled human liver microsome assay (pHLM) to confirm the analysis results of authentic urine samples collected after oral self‐administration of 2.5 mg 5F‐AB‐P7AICA. Analyses of pHLM and urine samples were performed by liquid chromatography?time‐of‐flight mass spectrometry and liquid chromatography–tandem mass spectrometry (LC–MS/MS). An LC–MS/MS method for the quantification of 5F‐AB‐P7AICA in serum was validated. Ten phase I metabolites were detected in human urine samples and confirmed in vitro. The main metabolites were formed by hydroxylation, amide hydrolysis, and hydrolytic defluorination, though – in contrast with most other synthetic cannabinoids – the parent compound showed the highest signals in most urine samples. The compound detection window was more than 45 hours in serum. The concentration‐time profile was best explained by a two‐phase pharmacokinetic model. 5F‐AB‐P7AICA was detected in urine samples until 65 hours post ingestion. Monitoring of metabolite M07, hydroxylated at the alkyl chain, next to parent 5F‐AB‐P7AICA, is recommended to confirm the uptake of 5F‐AB‐P7AICA in urinalysis. It seems plausible that the shift of the nitrogen atom from position 2 to 7 (e.g. 5F‐AB‐PINACA to 5F‐AB‐P7AICA) leads to a lower metabolic reactivity, which might be of general interest in medicinal chemistry.     

Elucidation of the metabolites of the novel psychoactive substance 4‐methyl‐N‐ethyl‐cathinone (4‐MEC) in human urine and pooled liver microsomes by GC‐MS and LC‐HR‐MS/MS techniques and of its detectability by GC‐MS or LC‐MSn standard screening approaches

4‐methyl‐N‐ethcathinone (4‐MEC), the N‐ethyl homologue of mephedrone, is a novel psychoactive substance of the beta‐keto amphetamine (cathinone) group. The aim of the present work was to study the phase I and phase II metabolism of 4‐MEC in human urine as well as in pooled human liver microsome (pHLM) incubations. The urine samples were worked up with and without enzymatic cleavage, the pHLM incubations by simple deproteinization. The metabolites were separated and identified by gas chromatography‐mass spectrometry (GC‐MS) and liquid chromatography‐high resolution‐tandem mass spectrometry (LC‐HR‐MS/MS). Based on the metabolites identified in urine and/or pHLM, the following metabolic pathways could be proposed: reduction of the keto group, N‐deethylation, hydroxylation of the 4‐methyl group followed by further oxidation to the corresponding 4‐carboxy metabolite, and combinations of these steps. Glucuronidation could only be observed for the hydroxy metabolite. These pathways were similar to those described for the N‐methyl homologue mephedrone and other related drugs. In pHLM, all phase I metabolites with the exception of the N‐deethyl‐dihydro isomers and the 4‐carboxy‐dihydro metabolite could be confirmed. Glucuronides could not be formed under the applied conditions. Although the taken dose was not clear, an intake of 4‐MEC should be detectable in urine by the GC‐MS and LC‐MSⁿ standard urine screening approaches at least after overdose. Copyright © 2014 John Wiley & Sons, Ltd.     

Phase I metabolism of the carbazole‐derived synthetic cannabinoids EG‐018, EG‐2201, and MDMB‐CHMCZCA and detection in human urine samples

Synthetic cannabinoids (SCs) are a structurally diverse class of new psychoactive substances. Most SCs used for recreational purposes are based on indole or indazole core structures. EG‐018 (naphthalen‐1‐yl(9‐pentyl‐9H‐carbazol‐3‐yl)methanone), EG‐2201 ((9‐(5‐fluoropentyl)‐9H‐carbazol‐3‐yl)(naphthalen‐1‐yl)methanone), and MDMB‐CHMCZCA (methyl 2‐(9‐(cyclohexylmethyl)‐9H‐carbazole‐3‐carboxamido)‐3,3‐dimethylbutanoate) are 3 representatives of a structural subclass of SCs, characterized by a carbazole core system. In vitro and in vivo phase I metabolism studies were conducted to identify the most suitable metabolites for the detection of these substances in urine screening. Detection and characterization of metabolites were performed by liquid chromatography–electrospray ionization–tandem mass spectrometry (LC–ESI–MS/MS) and liquid chromatography–electrospray ionization–quadrupole time‐of‐flight–mass spectrometry (LC–ESI–QToF–MS). Eleven in vivo metabolites were detected in urine samples positive for metabolites of EG‐018 (n = 8). A hydroxypentyl metabolite, most probably the 4‐hydroxypentyl isomer, and an N‐dealkylated metabolite mono‐hydroxylated at the carbazole core system were most abundant. In vitro studies of EG‐018 and EG‐2201 indicated that oxidative defluorination of the 5‐fluoropentyl side chain of EG‐2201 as well as dealkylation led to common metabolites with EG‐018. This has to be taken into account for interpretation of analytical findings. A differentiation between EG‐018 and EG‐2201 (n = 1) uptake is possible by the detection of compound‐specific in vivo phase I metabolites evaluated in this study. Out of 30 metabolites detected in urine samples of MDMB‐CHMCZCA users (n = 20), a metabolite mono‐hydroxylated at the cyclohexyl methyl tail is considered the most suitable compound‐specific consumption marker while a biotransformation product of mono‐hydroxylation in combination with hydrolysis of the terminal methyl ester function provides best sensitivity due to its high abundance.     

Lefetamine‐derived designer drugs N‐ethyl‐1,2‐diphenylethylamine (NEDPA) and N‐iso‐propyl‐1,2‐diphenylethylamine (NPDPA): Metabolism and detectability in rat urine using GC‐MS,LC‐MSn and LC‐HR‐MS/MS

N‐Ethyl‐1,2‐diphenylethylamine (NEDPA) and N‐iso‐propyl‐1,2‐diphenylethylamine (NPDPA) are two designer drugs, which were confiscated in Germany in 2008. Lefetamine (N,N‐dimethyl‐1,2‐diphenylethylamine, also named L‐SPA), the pharmaceutical lead of these designer drugs, is a controlled substance in many countries. The aim of the present work was to study the phase I and phase II metabolism of these drugs in rats and to check for their detectability in urine using the authors’ standard urine screening approaches (SUSA). For the elucidation of the metabolism, rat urine samples were worked up with and without enzymatic cleavage, separated and analyzed by gas chromatography‐mass spectrometry (GC‐MS) and liquid chromatography‐high resolution‐tandem mass spectrometry (LC‐HR‐MS/MS). According to the identified metabolites, the following metabolic pathways for NEDPA and NPDPA could be proposed: N‐dealkylation, mono‐ and bis‐hydroxylation of the benzyl ring followed by methylation of one of the two hydroxy groups, combinations of these steps, hydroxylation of the phenyl ring after N‐dealkylation, glucuronidation and sulfation of all hydroxylated metabolites. Application of a 0.3 mg/kg BW dose of NEDPA or NPDPA, corresponding to a common lefetamine single dose, could be monitored in rat urine using the authors’ GC‐MS and LC‐MSⁿ SUSA. However, only the metabolites could be detected, namely N‐deethyl‐NEDPA, N‐deethyl‐hydroxy‐NEDPA, hydroxy‐NEDPA, and hydroxy‐methoxy‐NEDPA or N‐de‐iso‐propyl‐NPDPA, N‐de‐iso‐propyl‐hydroxy‐NPDPA, and hydroxy‐NPDPA. Assuming similar kinetics, an intake of these drugs should also be detectable in human urine. Copyright © 2014 John Wiley & Sons, Ltd.     

UHPLC‐MS/MS and UHPLC‐HRMS identification of zolpidem and zopiclone main urinary metabolites and method development for their toxicological determination

Zolpidem and zopiclone (Z‐compounds) are non‐benzodiazepine hypnotics of new generation that can be used in drug‐facilitated sexual assault (DFSA). Their determination in biological fluids, mainly urine, is of primary importance; nevertheless, although they are excreted almost entirely as metabolites, available methods deal mainly with the determination of the unmetabolized drug. This paper describes a method for the determination in urine of Z‐compounds and their metabolites by ultra‐high‐pressure liquid chromatography/tandem mass spectrometry (UHPLC‐MS/MS) and UHPLC coupled with high resolution/high accuracy Orbitrap® mass spectrometry (UHPLC‐HRMS). The metabolic profile was studied on real samples collected from subjects in therapy with zolpidem or zopiclone; the main urinary metabolites were identified and their MS behaviour studied by MS/MS and HRMS. Two carboxy‐ and three hydroxy‐ metabolites, that could be also detected by gas chromatography/mass spectrometry (GC‐MS) as trimethylsylyl derivatives, have been identified for zolpidem. Also, at least one dihydroxilated metabolite was detected. As for zopiclone, the two main metabolites detected were N‐demethyl and N‐oxide zopiclone. For both substances, the unmetabolized compounds were excreted in low amounts in urine. In consideration of these data, a UHPLC‐MS/MS method for the determination of Z‐compounds and their main metabolites after isotopic dilution with deuterated analogues of zolpidem and zopiclone and direct injection of urine samples was set up. The proposed UHPLC‐MS/MS method appears to be practically applicable for the analysis of urine samples in analytical and forensic toxicology cases, as well as in cases of suspected DFSA. Copyright © 2013 John Wiley & Sons, Ltd.