Screening,quantification, and confirmation of synthetic cannabinoid metabolites in urine by UHPLC–QTOF–MS

Synthetic cannabinoids are one of the most significant groups within the category new psychoactive substances (NPS) and in recent years new compounds have continuously been introduced to the market of recreational drugs. A sensitive and quantitative screening method in urine with metabolites of frequently seized compounds in Norway (AB‐FUBINACA, AB‐PINACA, AB‐CHMINACA, AM‐2201, AKB48, 5F‐AKB48, BB‐22, JWH‐018, JWH‐073, JWH‐081, JWH‐122, JWH‐203, JWH‐250, PB‐22, 5F‐PB‐22, RCS‐4, THJ‐2201, and UR‐144) using ultra‐high pressure liquid chromatography–quadrupole time of flight–mass spectrometry (UHPLC–QTOF–MS) has been developed. The samples were treated with ß‐glucuronidase prior to extraction and solid‐phase extraction was used. Liquid handling was automated using a robot. Chromatographic separation was achieved using a C18‐column and a gradient of water and acetonitrile, both with 0.1% formic acid. Each sample was initially screened for identification and quantification followed by a second injection for confirmation. The concentrations by which the compounds could be confirmed varied between 0.1 and 12 ng/mL. Overall the validation showed that the method fulfilled the set criteria and requirements for matrix effect, extraction recovery, linearity, precision, accuracy, specificity, and stability. One thousand urine samples from subjects in drug withdrawal programs were analyzed using the presented method. The metabolite AB‐FUBINACA M3, hydroxylated metabolite of 5F‐AKB48, hydroxylated metabolite of AKB48, AKB48 N‐pentanoic acid, 5F‐PB‐22 3‐carboxyindole, BB‐22 3‐carboxyindole, JWH‐018 N‐(5‐hydroxypentyl), JWH‐018 N‐pentanoic acid, and JWH‐073 N‐butanoic acid were quantified and confirmed in 2.3% of the samples. The method was proven to be sensitive, selective and robust for routine use for the investigated metabolites.     

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.     

Analysis of 30 synthetic cannabinoids in oral fluid using liquid chromatography‐electrospray ionization tandem mass spectrometry

In recent years, the analysis of synthetic cannabinoids in human specimens has gained enormous importance in the broad field of drug testing. Nevertheless, the considerable structural diversity among synthetic cannabinoids already identified in ‘herbal mixtures’ hampers the development of comprehensive analytical methods. As the identification of the main metabolites of newly appearing substances is very laborious and time‐consuming, the detection of the parent compounds in blood samples is the current approach of choice for drug abstinence testing. Whenever blood sampling is not possible however, the need for alternative matrices arises. In this article, we present a fully validated liquid chromatography‐electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method for the analysis of 30 synthetic cannabinoids in oral fluid samples collected with the Dräger DCD 5000 collection device. The method proved to be suitable for the quantification of 28 substances. The limits of detection were in the range from 0.015 to 0.9 ng/ml, while the lower limits of quantification ranged from 0.15 to 3.0 ng/ml. The method was successfully applied to 264 authentic samples during routine analysis. A total of 31 samples (12%) was tested positive for at least one of the following synthetic cannabinoids: AM‐694, AM‐2201, JWH‐018, JWH‐019, JWH‐081, JWH‐122, JWH‐203, JWH‐210, JWH‐250, JWH‐307, MAM‐2201, and RCS‐4. Given that stabilization of the collection pads after sampling is warranted, the collection device provides satisfactory sensitivity. Hence, whenever blood sampling is not possible, the Dräger DCD 5000 collection device offers a good tool for the analysis of synthetic cannabinoids in oral fluid in the broad field of drug testing. Copyright © 2012 John Wiley & Sons, Ltd.     

Quantitative urine confirmatory testing for synthetic cannabinoids in randomly collected urine specimens

Synthetic cannabinoid intake is an ongoing health issue worldwide, with new compounds continually emerging, making drug testing complex. Parent synthetic cannabinoids are rarely detected in urine, the most common matrix employed in workplace drug testing. Optimal identification of synthetic cannabinoid markers in authentic urine specimens and correlation of metabolite concentrations and toxicities would improve synthetic cannabinoid result interpretation. We screened 20 017 randomly collected US military urine specimens between July 2011 and June 2012 with a synthetic cannabinoid immunoassay yielding 1432 presumptive positive specimens. We analyzed all presumptive positive and 1069 negative specimens with our qualitative synthetic cannabinoid liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method, which confirmed 290 positive specimens. All 290 positive and 487 randomly selected negative specimens were quantified with the most comprehensive urine quantitative LC‐MS/MS method published to date; 290 specimens confirmed positive for 22 metabolites from 11 parent synthetic cannabinoids. The five most predominant metabolites were JWH‐018 pentanoic acid (93%), JWH‐N‐hydroxypentyl (84%), AM2201 N‐hydroxypentyl (69%), JWH‐073 butanoic acid (69%), and JWH‐122 N‐hydroxypentyl (45%) with 11.1 (0.1‐2,434), 5.1 (0.1‐1,239), 2.0 (0.1‐321), 1.1 (0.1‐48.6), and 1.1 (0.1‐250) µg/L median (range) concentrations, respectively. Alkyl hydroxy and carboxy metabolites provided suitable biomarkers for 11 parent synthetic cannabinoids; although hydroxyindoles were also observed. This is by far the largest data set of synthetic cannabinoid metabolites urine concentrations from randomly collected workplace drug testing specimens rather than acute intoxications or driving under the influence of drugs. These data improve the interpretation of synthetic cannabinoid urine test results and suggest suitable urine markers of synthetic cannabinoid intake. This article is a U.S. Government work and is in the public domain in the USA.     

Rapid and sensitive screening and confirmation of thirty‐four aminocarbonyl/carboxamide (NACA) and arylindole synthetic cannabinoid drugs in human whole blood

We describe the development and validation of a method for the screening and confirmation of a range of chemically diverse synthetic cannabinoid drugs in human whole blood. The method targets the better known arylindole compounds as well as the emerging aminocarbonyl/ carboxamide (NACA) compounds. The approach consists of two separate extraction procedures designed to optimize recovery of each of these two classes, followed by analysis by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). The most significant novel compounds added were AB‐FUBINACA, ADBICA, 5 F‐ADBICA, ADB‐PINACA, ADB‐FUBINACA, ADB‐FUBINACA, 5 F‐ADB‐PINACA, 5 F‐ADB‐PINACA, AB‐PINACA, AB‐CHMINACA, and ADB‐CHMINACA. A third procedure is described for the quantitative confirmation of those compounds for which deuterated internal standards permitted quantitative analysis, including JWH‐018, JWH‐122, JWH‐081, JWH‐210, AM‐2201, XLR‐11, and UR‐144. The methods were successfully validated according to Scientific Working Group in Forensic Toxicology (SWGTOX) protocol for 34 compounds in common use in the United States in the period of 2014 and 2015, although other substances, unknown at the time may have been introduced to the market over the same time period. The method was determined to be free from carry‐over between samples, and no interference was found from other common therapeutic abused or novel psychoactive drugs. The methods were applied to the analysis of 1142 blood samples from forensic investigations, including post‐mortem examinations and driving impairment cases. The drugs most frequently detected were AB‐CHMINACA (18.6%), ADB‐CHMINACA (15%), XLR‐11 (5.5%), AB‐FUBINACA (4.5%), AB‐PINACA (3.9%), and ADB‐FUBINACA (2.3%). Copyright © 2016 John Wiley & Sons, Ltd.     

Metabolic patterns of JWH‐210, RCS‐4, and THC in pig urine elucidated using LC‐HR‐MS/MS: Do they reflect patterns in humans?

The knowledge of pharmacokinetic (PK) properties of synthetic cannabinoids (SCs) is important for interpretation of analytical results found for example in intoxicated individuals. In the absence of human data from controlled studies, animal models elucidating SC PK have to be established. Pigs providing large biofluid sample volumes were tested for prediction of human PK data. In this context, the metabolic fate of two model SCs, namely 4‐ethylnaphthalen‐1‐yl‐(1‐pentylindol‐3‐yl)methanone (JWH‐210) and 2‐(4‐methoxyphenyl)‐1‐(1‐pentyl‐indol‐3‐yl)methanone (RCS‐4), was elucidated in addition to Δ⁹‐tetrahydrocannabinol (THC). After intravenous administration of the compounds, hourly collected pig urine was analyzed by liquid chromatography‐high resolution mass spectrometry. The following pathways were observed: for JWH‐210, hydroxylation at the ethyl side chain or pentyl chain and combinations of them followed by glucuronidation; for RCS‐4, hydroxylation at the methoxyphenyl moiety or pentyl chain followed by glucuronidation as well as O ‐demethylation followed by glucuronidation or sulfation; for THC, THC glucuronidation, 11‐hydroxylation, followed by carboxylation and glucuronidation. For both SCs, parent compounds could not be detected in urine in contrast to THC. These results were consistent with those obtained from human hepatocyte and/or human case studies. Urinary markers for the consumption of JWH‐210 were the glucuronide of the N ‐hydroxypentyl metabolite (detectable for 3–4 h) and of RCS‐4 the glucuronides of the N ‐hydroxypentyl, hydroxy‐methoxyphenyl (detectable for at least 6 h), and the O ‐demethyl‐hydroxy metabolites (detectable for 4 h). Copyright © 2016 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.     

UR‐144 in products sold via the Internet: Identification of related compounds and characterization of pyrolysis products

The synthetic cannabinoid, UR‐144 ((1‐pentyl‐1H‐indol‐3‐yl)(2,2,3,3‐tetramethylcyclopropyl)methanone), was identified in commercial ‘legal high’ products (herbal, resin, and powder). Along with this, six related compounds were detected. The most abundant one (2.1) was identified as 4‐hydroxy‐3,3,4‐trimethyl‐1‐(1‐pentyl‐1H‐indol‐3‐yl)pentan‐1‐one, a product of the electrophilic addition of water to the cyclopropane moiety in UR‐144. Compound 2.1 was found to be undergo cyclisation which leads to the formation of two additional interconvertable compounds (2.3, tentatively identified as 1‐pentyl‐3‐(4,4,5,5‐tetramethyl‐4,5‐dihydrofuran‐2‐yl)‐1H‐indole which is stable only in absence of water and also observed as GC artifact) and 2.2, a protonated derivative of 2.3 which is formed in acidic solutions. The remaining compounds were identified as possible degradation products of the group 2 compounds (4,4,5,5‐tetramethyldihydrofuran‐2(3H)‐one and 1‐pentylindoline‐2,3‐dione) and intermediates or by‐products from the synthesis of UR‐144 ((1H‐indol‐3‐yl)(2,2,3,3‐tetramethylcyclopropyl)methanone, 1‐pentyl‐1H‐indole and 1‐(1‐pentyl‐1H‐indol‐3‐yl)hexan‐1‐one). Pyrolysis of herbal products containing the group 2 compounds or UR‐144 resulted in the formation of 3,3,4‐trimethyl‐1‐(1‐pentyl‐1H‐indol‐3‐yl)pent‐4‐en‐1‐one (3). This was confirmed by separate pyrolysis of 2.1 and UR‐144. Also, the two additional minor compounds, 1‐(1‐pentyl‐1H‐indol‐3‐yl)ethanone and 1‐(1‐pentyl‐1H‐indol‐3‐yl)propan‐1‐one, were detected. Pathways for these transformations are presented. Copyright © 2013 John Wiley & Sons, Ltd.     

Performance characteristics of an ELISA screening assay for urinary synthetic cannabinoids

Synthetic cannabinoids are marketed as legal alternatives to cannabis, as routine urine cannabinoid immunoassays do not detect synthetic cannabinoids. Laboratories are challenged to identify these new designer drugs that are widely available and represent a major public health and safety problem. Immunoassay testing offers rapid separation of presumptive positive and negative specimens, prior to more costly and time‐consuming chromatographic confirmation. The Neogen SPICE ELISA kit targets JWH‐018 N‐pentanoic acid as a marker for urinary synthetic cannabinoids. Assay performance was evaluated by analyzing 2469 authentic urine samples with the Neogen immunoassay and liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Two immunoassay cut‐off concentrations, 5 and 10 µg/L, classified samples as presumptive positive or negative, followed by qualitative LC‐MS/MS confirmation for 29 synthetic cannabinoids markers with limits of detection of 0.5–10 µg/L to determine the assay's sensitivity, specificity and efficacy. Challenges at ±25% of each cut‐off also were investigated to determine performance around the cut‐off and intra‐ and inter‐plate imprecision. The immunoassay was linear from 1 to 250 µg/L (r² = 0.992) with intra‐ and inter‐plate imprecision of ≤5.3% and <9%, respectively. Sensitivity, specificity, and efficiency results with the 5 µg/L cut‐off were 79.9%, 99.7%, and 97.4% and with the 10 µg/L cut‐off 69.3%, 99.8%, and 96.3%, respectively. Cross‐reactivity was shown for 18 of 73 synthetic cannabinoids markers evaluated. Good sensitivity, specificity, and efficiency, lack of sample preparation requirements, and rapid semi‐automation documented that the Neogen SPICE ELISA kit is a viable method for screening synthetic cannabinoids in urine targeting JWH‐018 N‐pentanoic acid. Copyright © 2014 John Wiley & Sons, Ltd.     

Analysis of AM‐2201 and metabolites in a drugs and driving case

This case report describes the analysis of AM‐2201 in plant material and its metabolites in human urine obtained from an operator of a motor vehicle in the United States. The samples were taken from the driver because of his illegal driving activities and, his subsequent erratic behaviour. The AM‐2201 was extracted from a sample of plant material by sonicating it in methanol, after which an aliquot was taken and diluted with aqueous phosphate buffer (pH 6) and extracted by solid‐phase extraction using a C8/aminopropyl SPE cartridge. The cartridges were washed, dried, and eluted with ethyl acetate‐ methanol solvent system. The urine sample was hydrolyzed with β‐glucuronidase at pH 6.8 before being diluted with aqueous phosphate buffer (pH 6) and extracted with the same type of SPE cartridge. After evaporation of the eluates, the samples were dissolved in mobile phase for analysis by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Analysis of the plant material determined the concentration to be 0.05% (AM2201) by mass of dry material. The concentration of AM‐2201 (AM2201‐N‐(4‐hydroxypentyl ) metabolite in the urine was found to be 3.1 ng/ml. The urine also contained 109 ng/ml of delta‐9‐tetrahydrocannabinol carboxylic acid but no other drugs including JWH‐018 metabolites. Copyright © 2013 John Wiley & Sons, Ltd.     

Quantification of curcumin,demethoxycurcumin, and bisdemethoxycurcumin in rodent brain by UHPLC/ESI‐Q‐TOF‐MS/MS after intra‐nasal administration of curcuminoids loaded PNIPAM nanoparticles

An ultra high performance liquid chromatography‐electrospray ionization‐synapt mass spectrometric method (UHPLC/ESI‐QTOF‐MS/MS) for the analysis of curcumin (Cur), demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC) in Wistar rat brain homogenate was developed and validated. The chromatographic separation was achieved on a Waters ACQUITY UPLC? BEH C18 (2.1mm × 100 mm; 1.7μm) column using isocratic mobile phase, consisting of acetonitrile: 10mM ammonium formate: formic acid (90:10:0.05v/v/v), at a flow rate of 0.2 ml min^‐1. The transitions occurred at m/z 367.0694/217.0598, 337.0717/173.0910, 307.0760/187.0844 for Cur, DMC, BDMC and m/z 307.0344/229.0677 for the IS (Nimesulide) respectively. The recovery of the analytes from Wistar rat brain homogenate was optimized using liquid‐liquid extraction technique (LLE) in (ethyl acetate: chloform) mixture. The total run time was 3.0 min and the elution of Cur, DMC, BDMC occurred at 1.6, 1.75, 1.70 min, and for the IS 1.87 min, respectively. The linear dynamic range was established over the concentration range of 1.00 ng mL^‐1 to 1000.0 ng mL^‐1(r²; 0.9909 ± 0.0011, 0.9911 ± 0.003, and 0.9919 ± 0.0013) for Cur, DMC, and BDMC, respectively. The intra and inter‐assay accuracy in terms of % CV for Cur, DMC, and BDMC was in the range 0.47–2.20, 0.47–1.65, and0.44–2.70, respectively. The lower limit of detection (LOD) and quantitation (LOQ) for Cur, DMC, and BDMC were 0.46, 0.05, 0.16 ng mL^‐1 and 0.153, 0.015, 0.052 ng mL^‐1, respectively. Analytes were stable and the method proved to be accurate (recovery, >85%), specific and was applied to evaluate the Cur, DMC, BDMC loaded PNIPAM NPs as vehicles for nose to brain drug delivery. Copyright © 2013 John Wiley & Sons, Ltd.     

Simultaneous determination of tanshinones and polyphenolics in rat plasma by UPLC‐MS/MS and its application to the pharmacokinetic interaction between them

The aim of this study was to investigate the pharmacokinetic interaction between tanshinones and polyphenolics which act as the main bioactive compounds in Saliva miltiorrhiza Bunge (SMB). Thus, a rapid and highly sensitive ultra‐performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated to determine the concentrations of Tanshinone IIA (TSIIA), Tanshinone I (TI), Cryptotanshinone (CT), Salvianolic acid B (Sal B), Protocatechuic aldehyde (PAL), Rosmarinic acid (RA), and Danshensu (DSS) in rat plasma. The Sprague–Dawley rats were allocated to three groups which orally administered tanshinones (DST), polyphenolics (DFS), and a mixture of tanshinones and polyphenolics (DTF). These samples were processed by a simple liquid‐liquid extraction (LLE) method with ethyl acetate. Chromatographic separation was achieved on an Acquity BEH C₁₈ column (100 mm × 2. 1 mm, 1.7 µm) with the mobile phase consisting of 0.1% (v/v) formic acid and acetonitrile by gradient elution at a flow rate of 0.4 mL/min. The detection was performed on a triple quadrupole‐tandem mass spectrometer TQ‐MS/MS equipped with negative and positive electrospray ionization (ESI) interface in multiple reaction monitoring (MRM) mode. The statistical analysis was performed by the Student's t‐test with P ≤ 0.05 as the level of significance. The method showed good precision, accuracy, recovery, sensitivity, linearity, and stability. The pharmacokinetic profiles and parameters of these polyphenolics changed when co‐administrated with tanshinones. The tanshinones improved the bioavailability of DSS, accelerated the eliminating rate of RA and Sal B and promoted their distribution in vivo. They also contributed to promoting the biotransformation of Sal B to DSS. The polyphenolics could affect the pharmacokinetic of tanshinones, especially CT and TSIIA. Furthermore, the biotransformation of CT to TSIIA and the bioavailability of TSIIA were both improved. This study may provide useful information to avoid unexpected increase of the plasma drug concentration in the clinical practice. Copyright © 2015 John Wiley & Sons, Ltd.     

Enantiomeric separation and quantification of R/S‐amphetamine in serum using semi‐automated liquid‐liquid extraction and ultra‐high performance supercritical fluid chromatography‐tandem mass spectrometry

The amphetamine molecule contains a chiral center and its enantiomers exhibit differences in pharmacological effects, with the S‐enantiomer mediating most of the central nervous system stimulating activity. The majority of prescribed amphetamine consists of the pure S‐enantiomer, but therapeutic formulations containing the R‐enantiomer in various proportions are also available. Illegal amphetamine remains available mainly as a racemic mixture of the R‐ and S‐enantiomers. To distinguish between legal and illegal consumption of amphetamine a method for enantiomeric separation and quantification of R/S‐amphetamine in serum was developed and validated using ultra‐high performance supercritical fluid chromatography‐tandem mass spectrometry (UHPSFC‐MS/MS). Sample preparation prior to UHPSFC‐MS/MS analysis was performed by a semi‐automated liquid–liquid extraction method. The UHPSFC‐MS/MS method used a Chiralpak AD‐3 column with a mobile phase consisting of CO₂ and 0.1% ammonium hydroxide in 2‐propanol/methanol (50/50, v/v). The injection volume was 2 μL and run time was 4 minutes. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions (m/z 136.1 > 119.0 and m/z 136.1 > 91.0). The calibration range was 12.5–1,000 nM for each analyte. The between‐assay relative standard deviations were in the range of 1.3–3.0%. Recovery was 73% and matrix effects ranged from 95 to 100% when corrected with internal standard. After development and validation, the method has been successfully implemented in our laboratory for both separation and quantification of R/S‐amphetamine and has proved to be a reliable and useful tool for distinguishing intake of R‐ and S‐amphetamine in authentic patient samples.     

Pharmacokinetic properties of the synthetic cannabinoid JWH‐018 in oral fluid after inhalation

Each year, synthetic cannabinoids occur in high numbers on the illicit drug market, but data on their detectability are rarely available. A pilot study was performed to assess adverse effects of JWH‐018, which is one of the oldest and best known synthetic cannabinoids. Oral fluid has been evaluated as a specimen for drug monitoring. Six subjects inhaled smoke derived from 2 and 3 mg JWH‐018. The drug and 10 of its metabolites were analyzed in oral fluid samples collected during the following 12 hours using the Quantisal collection device by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Maximum concentrations of JWH‐018 reached 2.2–2036 (median 25.7) ng/mL after inhalation and decreased during the next hour to only 0.08–8.42 (median 0.89) ng/mL. Metabolites were not found. During the elimination phase (median half‐life 1.69 hours), detection of the drug over 6–12 hours (median 8 hours) after inhalation was achieved (0.024 ng/mL limit of quantification). Oral fluid/serum ratios varied considerably intra‐ and inter‐individually in a range of 0.05–555 (median 1.38). The detection of JWH‐018 in oral fluid requires high analytical sensitivity even 1 hour after inhalation. The pharmacokinetic properties of inhaled JWH‐018 are similar to those of THC. Times for detection are typically less than 12 hours. High variability of the oral fluid/serum ratio precludes extrapolation of oral fluid concentrations to blood.     

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.     

Cytochrome P450‐mediated metabolism of the synthetic cannabinoids UR‐144 and XLR‐11

In recent years, synthetic cannabinoids have emerged in the illicit drug market, in particular via the Internet, leading to abuse of these drugs. There is currently limited knowledge about the specific enzymes involved in the metabolism of these drugs. In this study, we investigated the cytochrome P450 (CYP) enzymes involved in the metabolism of the two synthetic cannabinoids (1‐pentyl‐1H‐indol‐3‐yl)‐(2,2,3,3‐tetramethylcyclopropyl)methanone (UR‐144) and [1‐(5‐fluoropentyl)‐1H‐indol‐3‐yl)](2,2,3,3‐tetramethylcyclopropyl)methanone (XLR‐11). This study extends previous studies by identifying the specific CYP enzymes involved in the metabolism of UR‐144 and XLR‐11 utilizing a panel of nine recombinant enzymes (CYP1A2, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 3A4, and 2E1). This is followed by an investigation of the effect of specific inhibitors targeted against CYP1A2, 2B6, 2C9, 2C19, 2D6 and 3A4 in human liver microsomes (HLM). Incubations of UR‐144 and XLR‐11 with recombinant CYP enzymes revealed that UR‐144 and XLR‐11 are extensively metabolized by CYP3A4 at the tetramethylcyclopropyl (TMCP) moiety, but also CYP1A2 and CYP2C19 showed activity. Inhibition of CYP3A4 in HLM attenuated the metabolism of UR‐144 and XLR‐11, while inhibition of the other CYP enzymes in HLM had only minor effects. Thus, CYP3A4 is the major contributor to the CYP mediated metabolism of UR‐144 and XLR‐11 with minor contributions from CYP1A2. Users of UR‐144 and XLR‐11 are thus subject to the influence of potential drug‐drug interactions, if they are concomitantly medicated with CYP3A4 inducers (e.g. some antiepileptics) or inhibitors (e.g. some antifungal drugs). Copyright © 2015 John Wiley & Sons, Ltd.     

Quantification of dimethylsulfoxide (DMSO) in equine plasma and urine using HILIC‐MS/MS

This paper describes quantitative methods for the determination of dimethylsulfoxide (DMSO) in equine plasma and urine based on simple precipitation and dilution followed by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC‐MS/MS). DMSO is a polar solvent with analgesic and anti‐inflammatory properties. Its pharmacological features make it prohibited in horse racing. However, since DMSO is naturally present in the horses’ environment, international threshold values have been implemented for plasma and urine (1 and 15 µg/mL, respectively). Previously presented quantitative methods for the determination of DMSO are based on gas chromatography, thus demanding a tedious extraction step to transfer the analyte from the aqueous bodily fluid to an injectable organic solvent. The column used in the presented method was an Acquity BEH HILIC and the mobile phase was a mixture of ammonium acetate buffer and acetonitrile delivered as a gradient. Hexadeuterated DMSO (²H₆‐DMSO) was used as the internal standard. Validation was performed in the range of the international thresholds concerning selectivity, carry‐over, linearity, precision, accuracy, stability and inter‐individual matrix variation. The results fulfilled the predefined criteria and the methods were considered fit for purpose. Successful applications on real equine doping control samples were carried out with determined DMSO concentrations exceeding the international thresholds. Copyright © 2016 John Wiley & Sons, Ltd.     

Determination of a selection of anti‐epileptic drugs and two active metabolites in whole blood by reversed phase UPLC‐MS/MS and some examples of application of the method in forensic toxicology cases

Quantitative determination of anti‐epileptic drug concentrations is of great importance in forensic toxicology cases. Although the drugs are not usually abused, they are important post‐mortem cases where the question of both lack of compliance and accidental or deliberate poisoning might be raised. In addition these drugs can be relevant for driving under the influence cases. A reversed phase ultra‐performance liquid chromatography‐tandem mass spectrometry method has been developed for the quantitative analysis of the anti‐epileptic compounds carbamazepine, carbamazepine‐10,11‐epoxide, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, 10‐OH‐carbazepine, phenobarbital, phenytoin, pregabalin, and topiramate in whole blood, using 0.1 mL sample volume with methaqualone as internal standard. Sample preparation was a simple protein precipitation with acetonitrile and methanol. The diluted supernatant was directly injected into the chromatographic system. Separation was performed on an Acquity UPLC® BEH Phenyl column with gradient elution and a mildly alkaline mobile phase. The mass spectrometric detection was performed in positive ion mode, except for phenobarbital, and multiple reaction monitoring was used for drug quantification. The limits of quantification for the different anti‐epileptic drugs varied from 0.064 to 1.26 mg/L in blood, within‐day and day‐to‐day relative standard deviations from 2.2 to 14.7% except for phenobarbital. Between‐day variation for phenobarbital was 20.4% at the concentration level of 3.5 mg/L. The biases for all compounds were within ±17.5%. The recoveries ranged between 85 and 120%. The corrected matrix effects were 88–106% and 84–110% in ante‐mortem and post‐mortem whole blood samples, respectively. 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.