Gas Chromatography-electron Ionization-mass Spectrometry Research Articles

Analytical validation of fecal 3-bromotyrosine concentrations in healthy dogs and dogs with chronic enteropathy.

Studies that have used serum 3-bromotyrosine (3-BrY) to investigate eosinophil activation in dogs have found elevated 3-BrY levels in clinical patients with chronic enteropathy (CE). To our knowledge, a method to measure 3-BrY concentrations in feces has not been reported. We developed and analytically validated an electron ionization gas chromatography-mass spectrometry method to measure fecal 3-BrY concentrations in dogs. The mean and maximum fecal 3-BrY concentrations in healthy dogs ( n = 40) and dogs with CE ( n = 40) over 3 consecutive days were compared. Analytical validation had a limit of blank and a limit of detection of 2.5 and 3.7 mmol/g of feces, respectively. The mean coefficients of variation for precision and reproducibility for 3-BrY were 11.2% (range: 7.5-14.2%) and 10.1% (4.8-15.2%), respectively. The ranges of observed-to-expected ratios for linearity and accuracy were 81.3-125% and 85.4-120%, respectively. The reference intervals for mean and maximum fecal 3-BrY concentrations in 40 healthy dogs were 3.7-23.0 and 3.7-37.8 mmol/g of feces. Mean and maximum fecal 3-BrY concentrations in dogs with CE were significantly higher than those of healthy dogs ( p < 0.001). Further research is warranted to determine the clinical usefulness of fecal 3-BrY concentrations in dogs with CE.

Gas chromatography-mass spectrometry of sapucainha oil (Carpotroche brasiliensis) triacylglycerols comprising straight chain and cyclic fatty acids.

Sapucainha oil, which may be used to treat leprosy, comprises straight chain and cyclic fatty acids (FA), and triacylglycerols (TAG). The FA and TAG content of the oil sample was analysed using gas chromatography-electron ionisation mass spectrometry (GC-EIMS). FA analysis was performed after derivatisation to fatty acid methyl esters (FAME). For free FA and TAG analysis, the oil sample was dissolved in hexane and injected into a short, high-temperature column, for GC with MS analysis. Free FA and FAME were tentatively identified based on mass spectrum information of their molecular and fragment ions, as well as library matching. Overlapping TAG peaks were deconvoluted based on mass fingerprint data. The FA composition was utilised to predict possible TAG identities. FA residues of TAG were identified based on characteristic fragment ions, such as [M-RCO2]+, [RCO+128]+, [RCO+74]+ and RCO+ where R is the aliphatic hydrocarbon chain. FAME analysis showed that the cyclic FA hydnocarpic (36.1%), chaulmoogric (26.5%) and gorlic (23.6%) acids were the major components. In addition, straight chain FA such as palmitic, palmitoleic, stearic, oleic and linoleic acids were detected. Palmitic, oleic, hydnocarpic, chaulmoogric and gorlic acids were also detected as free FA in the oil sample. Six groups of TAG peaks were eluted from GC at temperatures ≥330°C. After deconvolution and mass spectrum analysis, each TAG peak group was revealed to comprise 2 to 5 co-eluted TAG molecules; >18 TAG were identified. These TAG consisted of a mix of both cyclic and straight chain FA, but were mostly derived from cyclic FA.

Optimization and validation of simultaneous analyses of ecgonine, cocaine, and seven metabolites in human urine by gas chromatography-mass spectrometry using a one-step solid-phase extraction.

The presence of ecgonine in urine has been proposed as an appropriate marker of cocaine use. Only a few methods have been published for their determination along with cocaine and the rest of its metabolites. Due to their high polarity and consequent solubility in water, these have low recoveries, which is why it is necessary to increase the sensitivity, by the formation of hydrochloric salts or multiderivatization of the analytes or by performing two solid-phase extractions (SPEs), considerably increasing the time and cost of the analysis. This work describes a fast and fully validated procedure for the simultaneous detection and quantification of ecgonine, ecgonine-methyl-ester, benzoylecgonine, nor-benzoylecgonine, m-hydroxybenzoylecgonine, cocaethylene, cocaine, norcocaine, and norcocaethylene in human urine (500μL) using one SPE and simple derivatization. Separation and quantification were achieved by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) in selected-ion monitoring mode. Quantification was performed by the addition of deuterated analogs as internal standards. Calibration curves were linear in the adopted ranges, with determination coefficients higher than 0.99. The lower limits of quantification ranged from 2.5 to 10ng/mL. The intra- and inter-day precision, calculated in terms of relative standard deviation, were 1.2%-14.9% and 1.8%-17.9%, respectively. The accuracy, in terms of relative error, was within a±16.4% interval. Extraction efficiency ranged from 84% to 103%. Compared with existing methods, the procedure described herein is fast, since only one SPE is required, and cost-effective. In addition, this method provides a high recovery for ecgonine, resulting in a better alternative to the previously published methods.

Determination of Thiodiglycol and Its Oxide in Biomedical Samples by Gas Chromatography–Mass Spectrometry

A unified procedure is proposed for the determination of thiodiglycol (TDG) and its oxide (TDGO) as markers of exposure to sulfur mustard in biomedical samples (urine, blood plasma, hairs) by gas chromatography–electron ionization mass spectrometry. The limit of detection of the procedure is comparable with the lowest level of endogenous TDG in biosamples (1 ng mL–1). Solid-phase microextraction of the derivatized analytes from the reaction mixture decreases the matrix effect. The procedure was tested in the analysis of rat biosamples obtained after in vivo exposure to sulfur mustard. The procedure was found to offer a higher potential in the retrospective determination of the total TDG and TDGO level in rat urine (within 7 days after exposure to 2 mg kg–1 of sulfur mustard) compared to the determination of the same markers in blood plasma. Blood plasma can be used for confirmatory analysis, provided the samples are taken within 2 days after exposure. Hair was found to be the least suitable biomatrix in view of the variability of the TDG background level in these samples and the possibility of contamination with TGD from other sources.

Comparison of the Characteristic Mass Fragmentations of Phenethylamines and Tryptamines by Electron Ionization Gas Chromatography Mass Spectrometry, Electrospray and Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

Characteristic mass fragmentation of 20 phenethylamine/tryptamine standards were investigated and compared by means of matrix assisted laser desorption/time-of-flight mass spectrometry (MALDI/TOFM), gas chromatography–electron ionization–mass spectrometry (GC-EI/MS) and liquid chromatography–electrospray ionization/mass spectrometry (LC-ESI/MS) methods. As a result, three characteristic peaks ([M]+ and fragments from the Cβ-Cα bond breakage) were found to be unique and contained information useful in identifying 2C series compounds based on the GC-EI/MS method. We found that the protonated molecular ion ([M+H]+) and two types of fragments produced from the α-cleavage and β-cleavage processes were useful mass spectral information in the rapid screening and confirmation of phenethylamine and tryptamine derivatives when ESI/MS and MALDI/TOFMS methods were applied. This assay was successfully used to determine samples that contain illicit drugs.

Mass spectral differentiation of positional isomers using multivariate statistics

Mass spectral analysis is considered to be a confirmatory method of analysis for the purpose of identifying controlled substances. However, the spectra of positional isomers are generally too visually similar to allow for differentiation. This study of fluoromethcathinone (FMC) and fluorofentanyl has shown that multivariate statistical analysis offers a feasible means of differentiating between electron ionization mass spectra of positional isomers. Three positional isomers of each compound (2-FMC, 3-FMC, 4-FMC, meta-fluorofentanyl, ortho-fluorofentanyl, and para-fluorofentanyl) were analyzed twice daily using gas chromatography/electron ionization mass spectrometry (GC/EI-MS) on six separate instruments over five days. This resulted in 60 mass spectra collected for each positional isomer. Principal component analysis (PCA) followed by linear discriminant analysis (LDA) was performed and successful differentiation of positional isomers was achieved. Leave-One-Sample-Out Cross Validation showed no errors for either group of isomers. Nineteen blind study samples were analyzed for each group of positional isomers with no misclassifications. Furthermore, data from previous case samples was analyzed using this method and in all cases the samples were properly attributed to the correct positional isomer. In addition to visual inspection of the LDA plots, objective classifications were conducted using the resulting posterior probabilities generated when LDA was performed. The results indicate multivariate statistical analysis is a promising addition to the analytical scheme of the identification of positional isomers. This would allow for higher confidence in the final identification of a compound without the need for additional instrumental analysis, saving laboratories both time and money.

Identification and characterization of the new psychoactive substance 3-fluoroethamphetamine in seized material

An amphetamine-type new psychoactive substance was identified in a fine white yellowish powder from a seizure control held in Spain in July 2017. Seized sample was deeply characterized by standard and high-performance analytical techniques like attenuated total reflectance-Fourier-transform infrared spectroscopy, gas chromatography–electron ionization–mass spectrometry, high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy, and ion mobility spectrometry. The seized sample was identified as 3-fluoroethamphetamine hydrochloride. To our knowledge this is the first report dealing with identification and characterization of 3-fluoroethamphetamine. Characterization data were compiled in order to provide the scientific community with sufficient information to allow a quick and accurate determination of 3-fluoroethamphetamine in future seizures.

Efficient derivatization of methylphosphonic and aminoethylsulfonic acids related to nerve agents simultaneously in soils using trimethyloxonium tetrafluoroborate for their enhanced, qualitative detection and identification by EI-GC–MS and GC–FPD

Trimethyloxonium tetrafluoroborate (TMO·BF4) has been used in the simultaneous derivatization of phosphonic and 2-aminoethylsulfonic acids related to nerve agents in different soils for their enhanced detection and identification by electron ionization gas chromatography-mass spectrometry (EI-GC–MS). The panel of acids consisted of five Schedule 2 phosphonic acids (methyl methylphosphonic acid, ethyl methylphosphonic acid, isopropyl methylphosphonic acid, pinacolyl methylphosphonic acid and cyclohexyl methylphosphonic acid) along with two sulfonic acids, N,N-diethyl-2-aminoethylsulfonic acid and N,N-diisopropyl-2-aminoethylsulfonic acid. The acids were converted to their corresponding methyl esters at ambient temperature when present at a 10μgg−1 concentration in three separate soils: Virginia type A soil, Ottawa sand and Nebraska EPA soil. The concentration of the acids reflects values typically encountered during proficiency tests (PTs) administered annually by the Organisation for the Prohibition of Chemical Weapons (OPCW). Derivatization times to yield detectable signals for the methyl ester products for all the acids was found to vary among all three soil samples, however, it was found that generally the most optimal time across all the matrices involved was 3h after the addition of TMO·BF4. Concomitantly, the analysis of the samples was complemented using GC coupled to flame photometric detection (GC–FPD). The inclusion of GC–FPD in the analysis yielded stronger signals for all seven methylated analytes making their detection after merely 3h possible relative to the ones initially obtained with EI-GC–MS. Regarding the three soils employed in our study, a greater methylating efficiency was found in the Virginia type A soil and Ottawa sand yielding results that were significantly larger in magnitude to those found during the same time points for the Nebraska EPA soil sample. Prolonged reaction times (up to 72h) were explored to find the time for the highest yield of methyl ester production were found instead to be deleterious to the process showcasing the importance of the fast yielding nature of the process specifically in situations where time-sensitive analysis is crucial (e.g. OPCW-PT).

Simultaneous determination of ibuprofen and its metabolites in complex equine urine matrices by GC-EI-MS in excretion study in view of doping control

A novel assay for the simultaneous determination of ibuprofen (IBU) and its four probable metabolites, 1-hydroxyibuprofen (1-OH IBU), 2-hydroxyibuprofen (2-OH IBU), 3-hydroxyibuprofen (3-OH IBU) and carboxyibuprofen (CBX IBU) in equine urine samples with the application of Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has been developed and elaborated. The new approach for sample preparation including minimizing matrix effects by the application of weak cation exchange solid-phase extraction together with strong cation exchange solid-phase extraction has been applied. The GC-EI-MS method was validated to demonstrate specificity, matrix effect, linearity, limit of detection (LOD) and quantification (LOQ), precision, trueness, carry-over and stability by using the matrix-matched quality control samples. Additionally, extraction yield was evaluated. The assay achieved the LOQ of 1.75 μg mL−1, 0.62 μg mL−1, 4.15 μg mL−1, 0.58 μg mL−1 and 4.04 μg mL−1 for IBU, 1-OH IBU, 2-OH IBU, 3-OH IBU and CBX IBU, respectively. The developed method has been successfully applied to the excretion study in horses, in which a single oral IBU dose was administered to twelve horses (mares and geldings) and equine urine samples were collected for 5 or 6 days after the drug administration. Data on the detection and determination of three IBU metabolites, 2-OH IBU, 3-OH IBU and CBX IBU in equine urine samples has been presented for the first time. The obtained results indicated the rapid excretion of IBU and its metabolites that were detectable only in the first day after the drug administration. IBU was mainly the most abundant compound detected in equine urine samples (with two exceptions in the case of samples collected from two horses, for which the highest instrumental responses were obtained for CBX IBU). The received results have indicated that two major IBU metabolites, CBX IBU and 2-OH IBU can be important markers for the IBU abuse in view of doping control in equestrian sports.

Simple Quantification of Lactones in Milk Fat by Solvent Extraction Using Gas Chromatography-Mass Spectrometry.

The analysis of lactones as an indicator of milk quality is important in food manufacturing. However, the extraction of lactones requires sensitive conditions due to their volatility. In this study, the parameters for resolution of lactone standards were evaluated by gas chromatography-electron ionization/mass spectrometry (GC-EI/MS) to develop a rapid and simple method for the quantification and compositional analysis of lactones in edible fats, especially milk fat. Fourteen lactone standards consisting of 6-16 carbon atoms were analyzed and their correction factors (CFs) were obtained by using δ-undecalactone as an internal standard. The CFs of the lactone standards followed the same trend for δ-lactones and γ-lactones. Three volume equivalents of organic solvent per unit sample yielded the best recovery in the lactone analysis. Notably, 91-114% lactone recovery for the standards was achieved with methanol as the extractant. This method was also applicable to other fat samples, such as virgin coconut oil that is thought to contain large amounts of lactones. The recovery of lactones from virgin coconut oil was in the range of 87-104%, indicating that the developed method is also applicable to solid or semi-solid fat samples. The lactone content of butter oil, coconut oil, and butter samples was calculated by using the obtained CFs and the results were in good agreement with those of previous reports. Consequently, the GC-EI/MS method developed in this study is deemed applicable for the quantification of lactones in fat samples.

Identification of polyethanolamines by chromatography–mass spectrometry

Presumable structures of polyethanolamines, synthesized by the catalytic β-hydroxyethylation of ammonia with an excess of ethylene oxide are determined by gas chromatography–electron ionization mass spectrometry and tandem mass spectrometry qualitatively, following fragmentation ways and also taking into account retention data. The preferable paths of consecutive reactions of the synthesis of polyethanolamines in a homologous series of isomers are found.

Identifying method validation and measurement uncertainty of brominated vegetable oil in soft drinks and carbonated waters commonly consumed in South Korea

This study investigated a method for validating and determining the measurement uncertainty for the composition of brominated vegetable oil (BVO) in soft drinks and carbonated waters commonly consumed in South Korea. First, we studied a simple and precise qualitative colorimetric method at the maximum residues level 15 ppm. And an analytical method using ion chromatography (IC) was validated and identified with brominated fatty acids by gas chromatography electron ionization mass spectrometry (GC/EI-MS). The measurement uncertainty was evaluated based on the precisional study and confirmed by the preliminary inter-laboratory study. For IC analysis, the recovery range of BVO was from 97.8% to 107.2% with relative standard deviations between 0.18% and 0.69%. In addition, the expanded uncertainty of the BVO was 1.59. These results indicate that the validated method is appropriate for identifying of BVO and can be used to verify the safety of soft drinks or carbonated waters containing BVO residues.

Simultaneous quantitation of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene in human plasma using solid-phase extraction and gas chromatography/mass spectrometry: Method validation and application to cardiovascular safety of therapeutic doses.

RATIONALE Several opioid analgesics have been related to the prolongation of cardiac repolarization, a condition which can be fatal. In order to establish a correct estimation of the risk/benefit balance of therapeutic doses of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene, it was necessary to develop an analytical method to determinate plasma concentrations of these opioids. METHODS Here we describe a method which incorporates strong alkaline treatment to obtain norpropoxyphene amide followed by a one-elution step solid-phase extraction, and without further derivatization. Separation and quantification were achieved by gas chromatography/electron ionization mass spectrometry (GC/EI-MS) in selected-ion monitoring mode. Quantification was performed with 500 μL of plasma by the addition of deuterated analogues as internal standards. RESULTS The proposed method has been validated in the linearity range of 25-1000 ng/mL for all the analytes, with correlation coefficients higher than 0.990. The lower limit of quantification was 25 ng/mL. The intra- and inter-day precision, calculated in terms of relative standard deviation, were 2.0-12.0% and 6.0-15.0%, respectively. The accuracy, in terms of relative error, was within a ± 10% interval. The absolute recovery and extraction efficiency ranged from 81.0 to 111.0% and 81.0 to 105.0%, respectively. CONCLUSIONS A GC/MS method for the rapid and simultaneous determination of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene in human plasma was developed, optimized and validated. This procedure was shown to be sensitive and specific using small specimen amounts, suitable for application in routine analysis for forensic purposes and therapeutic monitoring. To our knowledge, this is the first full validation of the simultaneous determination of these opioids and their metabolites in plasma samples.

Structural characterization of the new synthetic cannabinoids CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA and CUMYL-4CN-B7AICA

Synthetic cannabinoids are a group of new psychoactive compounds (NPS) that act as agonists at the cannabinoid receptor. First reported in 2008, they currently represent one of the largest groups of NPS that are monitored by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). Five samples (4 from the European RESPONSE project and one from daily casework) containing different synthetic cannabinoids were analyzed by a complex of analytical methods including gas chromatography–electron ionization mass spectrometry (GC–EI-MS), liquid chromatography–high resolution mass spectrometry (LC–HRMS), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Five new synthetic cannabinoids containing a cumyl moiety as a linked group were identified: CUMYL-PINACA, 5F-CUMYL-PINACA, CUMYL-4CN-BINACA, 5F-CUMYL-P7AICA, CUMYL-4CN-B7AICA. 5F-CUMYL-PINACA and 5F-CUMYL-P7AICA as well as CUMYL-4CN-BINACA and CUMYL-4CN-B7AICA are constitutional isomers and only differ in the position of a nitrogen atom. The article contains all analytical data for a proper identification and differentiation of the five cumyl compounds.

Ascaroside Profiling of Caenorhabditis elegans Using Gas Chromatography–Electron Ionization Mass Spectrometry

Nematodes such as the model organism Caenorhabditis elegans produce various homologous series of l-ascarylose-derived glycolipids called ascarosides, which include several highly potent signals in intra and interspecies communication as well as cross-kingdom interactions. Given their low concentrations and large number of structurally similar components, mass spectrometric screens based on high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) are commonly employed for ascaroside detection and quantification. Here, we describe a complementary gas chromatography-electron ionization mass spectrometry (GC-EIMS) screen that utilizes an ascarylose-derived K1-fragment ion signal at m/z 130.1 [C6H14OSi]+● to highlight known as well as yet unidentified ascaroside components in TMS-derivatized crude nematode exometabolome extracts. GC-EIMS-based ascaroside profiling of wild-type and mutant C. elegans facilitates the analysis of all basic ascarosides using the same ionization technique while providing excellent resolution for the complete homologous series with side chains ranging from 3 to 33 carbons. Combined screening for m/z 130.1 along with side chain-specific J1 [M - 173]+ and J2 [M - 291]+ fragment ions, as well as additional characteristic marker ions from α-cleavage, enables convenient structure assignment of ca. 200 components from wild-type and peroxisomal β-oxidation mutants including (ω - 1)-linked acyl, enoyl, β-hydroxyacyl, and 2-ketoalkyl ascarosides along with their (ω)-linked or α-methyl isomers and ethanolamide derivatives, as well as 2-hydroxyalkyl ascarosides. Given the widespread availability of GC-MS and its increasing popularity in metabolomics, this method will promote the identification of ascarosides in C. elegans and other nematodes.

Mechanism insights into the oxidative degradation of decabromodiphenyl ethane by potassium permanganate in acidic conditions

The KMnO4 degradation of decabromodiphenyl ethane (DBDPE), an additive in brominated flame retardants (BFRs), was investigated in a sulfuric acid system. The degradation tests showed that DBDPE reacted completely with KMnO4 in sulfuric acid, and a removal rate of 99.71% seems realistic. Many products were detected by liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-Q-TOF-MS) analysis and gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) analysis. The degradation initially forms 1,2-bis(perbromophenyl)ethane-1,2-dione (P1), pentabromophenol (P2), 2-(perbromophenyl)ethanol (P3) and pentabromobenzoic acid (P28), and the subsequent transformation of these primary intermediates generates ring-opening, five-membered ring and six-membered heterocycle products over time. Two main reaction pathways involving the direct oxidation of the C–C bond of the ethyl group and the cleavage of the C–C bond between ethyl carbon and the adjacent carbon were proposed, and were further confirmed by point charges analyses and Wiberg bond order calculations. Furthermore, the toxicity of DBDPE and its degradation products were evaluated using the ECOSAR program. DBDPE was found to be a toxic substance that could cause great damage to three kinds of organisms in different trophic levels, while all the transformation products were less toxic than parent compound.

Identification of the Synthetic Cannabinoid 1-(4-cyanobutyl)-N-(2-phenylpropan-2-yl)-1H-indazole-3-carboxamide (CUMYL-4CN-BINACA) in Plant Material and Quantification in Post-Mortem Blood Samples.

In May 2016, a new type of synthetic indazole-3-carboxamide cannabinoid (CUMYL-4CN-BINACA) was detected in seized plant material submitted to the Istanbul Council of Forensic Medicine by the National Police Office. The major ingredient in this material was purified using preparative liquid chromatography, and its structure was identified using liquid chromatography-high-resolution mass spectrometry (LC-HR/MS), gas chromatography-electron ionization/mass spectrometry (GC-EI/MS), nuclear magnetic resonance (NMR) spectroscopy and Fourier transform-infrared spectroscopy (FT-IR). Using HR-MS, the molecular formula of the compound was determined to be C22H24N4O (MW = 360.1950). The 1H and 13C-NMR and FT-IR spectrometric data revealed that the structure of compound was 1-(4-cyanobutyl)-N-(2-phenylpropan-2-yl)-1H-indazole-3-carboxamide (CUMYL-4CN-BINACA). After identification, it was quickly added to our generic drug list, and an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method was developed to determine its presence in blood samples. This study reports on the identification of CUMYL-4CN-BINACA in plant material using LC-HR/MS, GC-EI/MS, NMR and FT-IR as well as a validated method for quantification of CUMYL-4CN-BINACA in post-mortem blood samples by UPLC-MS-MS analysis. The quantification method has been validated in terms of linearity (0.1-50 ng/mL), selectivity, intra- and inter-assay accuracy and precision (CV < 15%), recovery (94-99%), limit of detection (0.07 ng/mL) and limit of quantification (0.1 ng/mL). Matrix effects, stability and process efficiency were also assessed. The method has been applied to 2,350 post-mortem blood samples from the autopsy cases in the Morgue Department of the Council of Forensic Medicine (Istanbul, Turkey) between 1 July 2016 and 31 December 2016.

Cannabimimetic activities of cumyl carboxamide-type synthetic cannabinoids

1-Pentyl-N-(2-phenylpropan-2-yl)-1H-indazole-3-carboxamide (CUMYL-PINACA) is a carboxamide-type synthetic cannabinoid comprising a cumylamine moiety. Recently, the detection of CUMYL-PINACA and some analogs in illicit drug products has been reported by the European Monitoring Centre for Drugs and Drug Addiction. In this study, we synthesized seven cumyl carboxamide-type synthetic cannabinoids (CUMYL-PINACA, CUMYL-5F-PINACA, CUMYL-PICA, CUMYL-5F-PICA, CUMYL-THPINACA, CUMYL-BICA, and CUMYL-5F-P7AICA) and evaluated their activities as CB1 and CB2 receptor agonists. We also showed the analytical characterization of these compounds using gas chromatography–electron ionization-mass spectrometry. All of the evaluated compounds exhibited moderate to strong activities as agonists acting on both CB1 and CB2 receptors with EC50 values in the range of 8.1 × 10−10–7.8 × 10−7 mol/L for CB1 and from 2.5 × 10−10 to 9.1 × 10−6 mol/L for CB2. The EC50 data presented will be helpful to understand the effects of these compounds in the forensic cases. Furthermore, other new cumyl carboxamide-type synthetic cannabinoids, which will be potentially distributed in the future, will probably have the activities as agonists acting on both CB1 and CB2 receptors.

Investigative probabilistic inferences of smokeless powder manufacturers utilizing a Bayesian network

Chemical and physical characteristics for 169 smokeless reloading powders were utilized in the development of a Bayesian network for inference of the powder manufacturer. The chemical characteristics of the smokeless powders were encoded using the most intense ions in their total ion spectra from gas chromatography-electron ionization-mass spectrometry (GC-EI-MS), which were previously determined from agglomerative hierarchical cluster analysis. Physical characteristics included as network nodes were the average kernel diameter and length, shape, color, luster, absence/presence of a bias cut and absence/presence of a perforation, which are commonly considered in casework. A Bayesian network was compiled using R code, written in-house. Performance of the network was validated by 100 iterations of stratified cross validation, withholding 10% of the data for testing and using the remaining 90% of the data to develop probability tables for the network. Posterior probabilities of the powder manufacturers were calculated for each test sample, and manufacturer inferences were made based on the highest posterior probability. The sensitivity and specificity of the fully instantiated network was examined for each manufacturer. Other performance metrics, including the positive and negative predictive values (PPV and NPV), which take into account the prevalence of each manufacturer, were also examined. The PPV ranged from 0.59 to 0.81 for individual manufacturers when all nodes of the network were instantiated. The NPV for fully instantiated networks ranged from 0.82 to 0.99 for individual manufacturers.

Isomeric discrimination of synthetic cannabinoids by GC-EI-MS: 1-adamantyl and 2-adamantyl isomers of N-adamantyl carboxamides.

N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (APINACA) and N-(1-adamantyl)-1-pentyl-1H-indole-3-carboxamide (APICA) are carboxamide-type synthetic cannabinoids comprising indazole/indole-3-carboxylic acid and adamantan-1-amine moieties. However, in the case of compounds like APINACA or APICA, adamantyl positional isomers exist, wherein either adamantan-1-amine or adamantan-2-amine is present. These adamantyl positional isomers have not been reported in previous studies, and no analytical data are available. To avoid misidentification of adamantyl carboxamide-type synthetic cannabinoids, it is important to develop methods to discriminate these adamantyl positional isomers. In this study, we report the analytical characterization by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS). For providing analytical standards, we synthesized eight carboxamide-type synthetic cannabinoids (APINACA 2-adamantyl isomer, APICA 2-adamantyl isomer, 5 F-APINACA 2-adamantyl isomer, 5 F-APICA 2-adamantyl isomer, 5Cl-APINACA, 5Cl-APINACA 2-adamantyl isomer, adamantyl-THPINACA, 2-adamantyl-THPINACA) and purchased four 1-adamantyl derivatives (APINACA, APICA, 5 F-APINACA, 5 F-APICA). Although the retention times of the isomers are similar, 1-adamantyl carboxamides can be clearly discriminated from their 2-adamantyl isomers based on their different fragmentation patterns in the EI-MS spectra. Specifically, EI-MS spectra for adamantylindazole carboxamides showed remarkable differences between the 1-adamantyl and 2-adamantyl isomers. On the other hand, EI-MS spectra for adamantylindole carboxamides were similar, but the diagnostic ions of the 2-adamantyl isomers were observed. The method described herein was applicable to all compounds tested in this study and is expected to be of use for isomeric differentiation between other untested adamantyl carboxamide-type synthetic cannabinoids. Copyright © 2016 John Wiley & Sons, Ltd.