Urinary excretion profiles of 11-nor-9-carboxy-delta9-tetrahydrocannabinol and 11-hydroxy-delta9-THC: cannabinoid metabolites to creatinine ratio study IV

The objective of this study was to compare urinary excretion patterns of two cannabinoid metabolites in subjects with a history of chronic marijuana use. The first metabolite analyzed was nor-9-carboxy-delta9-tetrahydrocannabinol (delta9-THC-COOH), the major urinary cannabinoid metabolite that is pharmacologically inactive. The second metabolite 11-OH-delta9-THC is an active cannabinoid metabolite and is not routinely measured. Urine specimens were collected from four subjects on 12-20 occasions > or = 96 h apart in an uncontrolled clinical setting. Creatinine was analyzed in each urine specimen by the colorimetric modified Jaffé reaction on a SYVA 30R biochemical analyzer. All urine specimens analyzed for 11-OH-delta9-THC had screened positive for cannabinoids with the EMIT II Plus cannabinoids assay (cut-off 50 ng/mL) on a SYVA 30R analyzer and submitted for delta9-THC-COOH confirmation by GC-MS (cut-off concentration 15 ng/mL). Eleven-OH-delta9-THC was measured by GC-MS with a cut-off concentration of 3 ng/mL. Both GC-MS methods for cannabinoid metabolites used deuterated internal standards for quantitative analysis. The mean (range) of urinary delta9-THC-COOH concentration was 1153 ng/mL (78.7-2634) with a cut-off of 15 ng/mL. The mean (range) of delta9-THC-COOH/creatinine ratios (ng/mL delta9-THC-COOH/mmol/L creatinine) was 84.1 (8.1-122.1). The mean (range) urinary of 11-OH-delta9-THC concentration was 387.6 ng/mL (11.9-783) with a cut-off of 3 ng/mL, and the mean (range) of 11-OH-delta9-THC/creatinine ratio (ng/mL 11-OH-delta9-THC/mmol/L creatinine) was 29.7 (1.2-40.7). Of the 63 urine specimens submitted for delta9-THC-COOH confirmation by GC-MS, 59/63 urine specimens (94%) were positive for delta9 -THC-COOH and 51/63 (81%) were positive for 11-OH-delta9-THC. Overall, the concentrations of 11-OH-delta9-THC in urine specimens collected > or = 96 h apart were lower than delta9-THC-COOH concentrations in 50/51 of the urine specimens in this population. Further urinary cannabinoid excretion studies are needed to assess whether 11-OH-delta9-THC analyses have a role when assessing previous marijuana or hashish use in chronic users whose urine specimens remain positive for delta9-THC-COOH for an extended period of time after last drug use.     

Detection of delta 9-THC in saliva by capillary GC/ECD after marihuana smoking

A method is described for the determination of delta 9-tetrahydrocannabinol (delta 9-THC) in the saliva by the use of a combination of moving-precolumn injector and glass capillary gas chromatograph with electron capture detector (GC/ECD). There were no interfering peaks due to impurities around the peak of pentafluoropropyl derivative of delta 9-THC (delta 9-THC-PFP). This GC/ECD method was linear over the range of 5-200 ng/ml of delta 9-THC-PFP. The lower detection limit was approximately 1 ng/ml. delta 9-THC content in the saliva after experimental marihuana smoking was measured by this method. It was demonstrated that for at least 4 h after smoking the level of delta 9-THC was sufficient for detection.     

Analysis of 11-nor-9-carboxy-delta(9)-tetrahydrocannabinol in biological samples by gas chromatography tandem mass spectrometry (GC/MS-MS)

Gas chromatography tandem mass spectrometry (GC/MS-MS) analysis of 11-nor-carboxy-delta(9)-tetrahydrocannabinol (delta(9)-THC-COOH), the major metabolite of delta(9)-tetrahydrocannabinol, in biological samples is reported. The proposed method, using deuterated delta(9)-THC-COOH as an internal standard, is able to detect the major metabolite of cannabis derivatives at very low levels (picograms/millilitre) with high specificity. These characteristics render the proposed analytical procedure suitable for confirmatory analysis in drug testing for cannabis use.     

Use of headspace solid-phase microextraction (HS-SPME) in hair analysis for organic compounds

Headspace solid phase microextraction (HS-SPME) has advantages of high purity of the extract, avoidance of organic solvents and simple technical manipulation and can be used in combination with gas chromatography-mass spectrometry (GC-MS) in the hair analysis of a number of drugs. HS-SPME coupled with the hydrolysis of the hair matrix by 4% sodium hydroxide in the presence of excess sodium sulphate and of a suitable internal standard proved to be a convenient one-step method for the measurement of many lipophilic basic drugs such as nicotine, amphetamine derivatives, local anaesthetics, phencyclidine, ketamine, methadone, diphenhydramine, tramadol, tricyclic antidepressants and phenothiazines. Detection limits were between 0.05 and 1.0 ng/mg. From spiked 10-mg hair samples absolute recoveries between 0.04 and 5.7% were found. These recoveries decreased considerably if larger sample amounts were used, perhaps due to increased drug solubility in the aqueous phase or to elevated viscosity in the presence of dissolved hair proteins. Because of the phenolic hydroxyl group a change of pH after alkaline hair digestion (by adding excess orthophosphoric acid) was necessary for the detection of delta 9-tetrahydrocannabinol (delta 9-THC), cannabinol (CBN) and cannabidiol (CBD) by HS-SPME. Nevertheless, the detection limits were such that only CBN could be detected in hair of a consumer. Clomethiazole, a compound hydrolysed in alkali, was measured by HS-SPME after extraction with aqueous buffer. The detection limit was 0.5 ng/mg. Cocaine could not be detected by HS-SPME. The application of HS-SPME to hair samples from several forensic and clinical cases is described.     

Potency trends of delta9-THC and other cannabinoids in confiscated marijuana from 1980-1997

The analysis of 35,312 cannabis preparations confiscated in the USA over a period of 18 years for delta-9-tetrahydrocannabinol (delta9-THC) and other major cannabinoids is reported. Samples were identified as cannabis, hashish, or hash oil. Cannabis samples were further subdivided into marijuana (loose material, kilobricks and buds), sinsemilla, Thai sticks and ditchweed. The data showed that more than 82% of all confiscated samples were in the marijuana category for every year except 1980 (61%) and 1981 (75%). The potency (concentration of delta9-THC) of marijuana samples rose from less than 1.5% in 1980 to approximately 3.3% in 1983 and 1984, then fluctuated around 3% till 1992. Since 1992, the potency of confiscated marijuana samples has continuously risen, going from 3.1% in 1992 to 4.2% in 1997. The average concentration of delta9-THC in all cannabis samples showed a gradual rise from 3% in 1991 to 4.47% in 1997. Hashish and hash oil, on the other hand, showed no specific potency trends. Other major cannabinoids [cannabidiol (CBD), cannabinol (CBN), and cannabichromene (CBC)] showed no significant change in their concentration over the years.     

Urinary excretion profiles of 11-nor-9-carboxy-Delta9-tetrahydrocannabinol. Study III. A Delta9-THC-COOH to creatinine ratio study

Huestis and Cone reported in [J. Anal. Toxicol. 22 (1998) 445] that serial monitoring of Delta9-THC-COOH/creatinine ratios in paired urine specimens collected at least 24h apart could differentiate new drug use from residual Delta(9)-THC-COOH excretion following acute marijuana use in a controlled setting. The best accuracy (85.4%) for predicting new marijuana use was for a Delta(9)-THC-COOH/creatinine ratio > or = 0.5 (dividing the Delta9-THC-COOH/creatinine ratio of specimen no. 2 by the specimen no. 1 ratio). In previous studies in this laboratory [J. Anal. Toxicol. 23 (1999) 531 and Forensic Sci. Int. 133 (2003) 26], urine specimens were collected from chronic marijuana users > or = 24 h or > = 48 h apart in an uncontrolled setting. Subjects with a history of chronic marijuana use were screened for cannabinoids with the EMIT II Plus cannabinoids assay (cut-off 50 ng/ml) followed by confirmation for Delta9-THC-COOH by GC-MS (cut-off 15 ng/ml). Creatinine was analyzed as an index of dilution. The objective of the present study was to evaluate whether creatinine corrected specimens could differentiate new marijuana or hashish use from the excretion of residual Delta(9)-THC-COOH in chronic marijuana users based on the Huestis 0.5 ratio. Urine specimens (N=376) were collected from 29 individuals > or = 96 h between urine collections. The mean urinary Delta9-THC-COOH concentration was 464.4 ng/ml, mean Delta9-THC-COOH/creatinine ratio (ng/(ml Delta9-THC-COOH mmoll creatinine)) was 36.8 and the overall mean Delta9-THC-COOH/creatinine ratio of specimen 2/mean Delta9-THC-COOH/creatinine ratio of specimen 1 was 1.37. The Huestis ratio calculation indicated new drug use in 83% of all sequentially paired urine specimens. The data were sub-divided into three groups (Groups A-C) based on mean Delta9-THC-COOH/creatinine values. Interindividual mean Delta9-THC-COOH/creatinine values ranged from 4.7 to 13.4 in Group A where 80% of paired specimens indicated new drug use (N=10) and 20.4-39.6 in Group B where 83.6% of paired specimens indicated new drug use (N=7). Individual mean Delta9-THC-COOH/creatinine values ranged from 44.2 to 120.2 in Group C where 84.5% of paired urine specimens indicated new marijuana use (N=12). Correcting Delta9-THC-COOH excretion for urinary dilution and comparing Delta9-THC-COOH/creatinine concentration ratios of sequentially paired specimens (collected > or = 96 h apart) may provide an objective indicator of ongoing marijuana or hashish use in this population.     

Urinary excretion profiles of 11-nor-9-carboxy-Delta9-tetrahydrocannabinol: a Delta9-THC-COOH to creatinine ratio study #2

Subjects with a history of chronic marijuana use were screened for cannabinoids in urine specimens with the EMIT((R)) II Plus cannabinoids assay with a cut-off value of 50 ng/ml. All presumptively positive specimens were submitted for confirmatory analysis for the major urinary cannabinoid metabolite (Delta(9)-THC-COOH) by GC-MS with a cut-off value of 15 ng/ml. Creatinine was analyzed in each specimen as an index of dilution. Huestis and Cone [J. Anal. Toxicol. 22 (1998) 445] reported that serial monitoring of Delta(9)-THC-COOH to creatinine ratios in paired urine specimens collected at least 24h apart could differentiate new drug use from residual Delta(9)-THC-COOH excretion. The best accuracy (85.4%) for predicting new marijuana use was a Delta(9)-THC-COOH/creatinine ratio > or =0.5 (dividing the Delta(9)-THC-COOH to creatinine ratio of specimen 2 by the specimen 1 ratio). In a previous study in this laboratory [J. Anal. Toxicol. 23 (1999) 531], urine specimens were collected from chronic marijuana users at least 24h apart and dilute urine specimens (creatinine values <2.2 micromol/l) were excluded from the data analysis. The objective of the present study was to determine whether creatinine corrected urine specimens positive for cannabinoids could differentiate new marijuana use from the excretion of residual Delta(9)-THC-COOH in chronic users of marijuana based on the Huestis 0.5 ratio. Urine specimens (N=946) were collected from 37 individuals with at least 48h between collections. All urine specimens were included in the data review irrespective of creatinine concentration. The mean urinary Delta(9)-THC-COOH concentration was 302.4 ng/ml, mean Delta(9)-THC-COOH/creatinine ratio (ng/ml Delta(9)-THC-COOH/(mmol/l) creatinine) was 29.3 and the Huestis ratio calculation indicated new drug use in 83% of all sequentially paired urine specimens. The data were sub-divided into three groups (A-C) based on the mean Delta(9)-THC-COOH/creatinine values. Interindividual Delta(9)-THC-COOH/creatinine mean values ranged from 2.2 to 13.8 in group A (264 specimens, N=15 subjects) where 80.7% of paired specimens indicated new drug use. In group B, mean Delta(9)-THC-COOH/creatinine values ranged from 15.3 to 37.8 in 444 specimens (N=14 subjects) and 83.3% of paired specimens indicated new drug use. In group C, individual mean Delta(9)-THC-COOH/creatinine values were >40.1 (41.3-132.5) in 238 urine specimens (N=8 subjects) and 85.3% of paired urine specimens indicated new marijuana use. Correcting Delta(9)-THC-COOH excretion for urinary dilution and comparing Delta(9)-THC-COOH/creatinine concentration ratios of sequentially paired specimens (collected at least 48h apart) provided an objective indicator of new marijuana use in this population.     

Correlations on radioimmunoassay, fluorescence polarization immunoassay, and enzyme immunoassay of cannabis metabolites with gas chromatography/mass spectrometry analysis of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in urine specimens.

Results obtained from three commercial immunoassay kits, Abuscreen, TDx, and EMIT, commonly used for the initial test of urine cannabinoids (and metabolites) were correlated with the 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (9-THC-COOH) concentration as determined by GC/MS. Correlation coefficients obtained based on 26 (out of 1359 total sample population) highly relevant samples, are 0.601 and 0.438 for Abuscreen and TDx. Correlation coefficients obtained from a parallel study on a different set of 47 (out of 5070 total sample population) highly relevant specimens are 0.658 and 0.575 for Abuscreen and Emit. The immunoassay concentration levels, that correspond to the commonly used 15 ng/ml GC/MS cutoff value for 9-THC-COOH, as calculated from the regression equations are 82 ng/ml and 75 ng/ml for TDx and EMIT and 120 ng/ml and 72 ng/ml for Abuscreen manufactured at two different time periods. The difference of these calculated corresponding concentrations provides quantitative evidence of the reagent specificity differences.     

A comparative analysis of Cannabis material

Extracts of 100 plant-like or resinous materials were analyzed for CBD, CBC, delta 9-THC, and CBN by GC using two different column packings and by GC-MS. Our independent identification of these cannabinoids confirmed those of other forensic science analysts who used microscopic examination, the Duquenois-Levine color test, and TLC for their analyses of the same samples. The identifications of cannabinoids by forensic acience analysts using TLC were corroborated by GC-MS analysis of hexane extracts of appropriate chromatogram spots.     

Hemolyzed blood and serum levels of delta 9-THC: effects on the performance of roadside sobriety tests

A pilot study was conducted to ascertain the range of induced hemolyzed blood/serum delta 9-tetrahydrocannabinol (delta 9-THC) concentrations in 58 human subjects. Subjects were tested within 5 min of smoking a delta 9-THC cigarette and then at half-hour intervals to 150 min. The subjects initially demonstrated a broad range of delta 9-THC hemolyzed blood levels, which settled within an hour to levels comparable to those measured in California drivers who had been stopped for impaired driving, arrested, and tested for delta 9-THC. Serum levels, when correlated with performance or roadside sobriety tests, demonstrated a broad range (5 to 183 ng/mL) of delta 9-THC levels and an "adaptation" effect in the subjects' perception of their own impairment. Although this preliminary study was not a double-blind placebo experiment, the overall performance of human subjects demonstrated the "adaptation" effect, which may be a significant factor in making judgments while performing such complex tasks as driving. Also, the effects of the drug extended beyond the period of elevated delta 9-THC blood levels, perhaps because of THC metabolites that may contribute to impairment or the persistence of THC in the central nervous system. This pilot study will lay the groundwork for a program designed to determine the epidemiology and behavior correlates of marijuana use in motorists.     

Benzoylecgonine (cocaine metabolite) detection in hair samples of jail detainees using radioimmunoassay (RIA) and gas chromatography/mass spectrometry (GC/MS)

Benzoylecgonine (BE) was detected in hair samples using nonproprietary extraction methodology and modifications of well-established radioimmunoassay (RIA) screening/quantitative gas chromatography/mass spectrometry (GC/MS) confirmation procedures. Samples collected anonymously from a population of 48 jail detainees weighed between 5.3 and 61.2 mg. All of the 22 hair samples which had RIA results indicating the presence of BE or immunologically similar substances above a cutoff amount of 1.25 ng/sample (50 ng/mL) were confirmed by GC/MS. Several varieties of hair color and texture were tested, although in each general category there were samples which contained BE as well as other samples which did not reveal detectable amounts of BE. The range of concentrations in 22 hair extracts that screened positive were 0.26 to 18 ng/mg hair as determined by GC/MS. In comparison with other reports of cocaine-related substances in hair, these data show consistent concentrations.     

Weather-induced changes in cannabinoid content of hair

Authentic hair samples from Cannabis users and a drug free hair sample which was separately spiked with tetrahydrocannabinol (THC), cannabidiol (CBD) or cannabinol (CBN) were exposed outside as well as to natural sunlight at prevailing and elevated humidity in quartz glass tubes during 8 weeks. In addition, authentic and spiked hair samples were exposed to xenon arc radiation in a light exposure cabinet for 24 hours. Stability of THC, CBD and CBN in authentic samples differed from that of the spiked hair. The radiation experiment revealed that CBN could not be measured in hair which had been spiked with THC. Under all conditions chosen the concentrations of THC, CBD and CBN decreased. At high humidity the concentrations declined more rapidly. In both authentic and spiked samples THC was most unstable compared to CBD and CBN. Therefore, in hair analysis determination of CBD and CBN seems promising to detect Cannabis exposure even under unfavorable conditions.     

GC-MS/MS法测定人头发中的大麻酚类及其代谢物

目的 建立同时检测头发中△9-四氢大麻酚(THC)、大麻酚(CBN)、大麻二酚(CBD)和△9-四氢大麻酸(THC-COOH)的分析方法.方法头发样品加入氘代内标△9-四氢大麻酸(THC-COOH-d3),经碱水解后,以混合溶剂[V(正己烷)∶V(乙酸乙酯=9∶1]进行提取,吹干,残留物经双(三甲基硅烷基)三氟乙酰胺(BSTFA)衍生化,用GC-MS/MS方法进行分析.结果 头发中THC-COOH、THC、CBN和CBD的最低检出限分别为4、4、10和20 pg· mg-1,各化合物在0.04～5ng· mg-1呈良好的线性关系(r＞0.999),方法精密度、准确度均符合要求.结论本方法选择性强、灵敏度高,适用于头发中CBD、CBN、THC及其代谢物THC-COOH的分析,并成功应用于实际案例中.     

Validated method for the simultaneous determination of Delta9-THC and Delta9-THC-COOH in oral fluid, urine and whole blood using solid-phase extraction and liquid chromatography-mass spectrometry with electrospray ionization

A fully validated, sensitive and specific method for the extraction and quantification of Delta(9)-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Delta(9)-THC (THC-COOH) and for the detection of 11-hydroxy-Delta(9)-THC (11-OH THC) in oral fluid, urine and whole blood is presented. Solid-phase extraction and liquid chromatography-mass spectrometry (LC-MS) technique were used, with electrospray ionization. Three ions were monitored for THC and THC-COOH and two for 11-OH THC. The compounds were quantified by selected ion recording of m/z 315.31, 329.18 and 343.16 for THC, 11-OH THC and THC-COOH, respectively, and m/z 318.27 and 346.26 for the deuterated internal standards, THC-d(3) and THC-COOH-d(3), respectively. The method proved to be precise for THC and THC-COOH both in terms of intra-day and inter-day analysis, with intra-day coefficients of variation (CV) less than 6.3, 6.6 and 6.5% for THC in saliva, urine and blood, respectively, and 6.8 and 7.7% for THC-COOH in urine and blood, respectively. Day-to-day CVs were less than 3.5, 4.9 and 11.3% for THC in saliva, urine and blood, respectively, and 6.2 and 6.4% for THC-COOH in urine and blood, respectively. Limits of detection (LOD) were 2 ng/mL for THC in oral fluid and 0.5 ng/mL for THC and THC-COOH and 20 ng/mL for 11-OH THC, in urine and blood. Calibration curves showed a linear relationship for THC and THC-COOH in all samples (r(2)>0.999) within the range investigated. The procedure presented here has high specificity, selectivity and sensitivity. It can be regarded as an alternative method to GC-MS for the confirmation of positive immunoassay test results, and can be used as a suitable analytical tool for the quantification of THC and THC-COOH in oral fluid, urine and/or blood samples.     

The cannabinoid content of marihuana samples seized in Greece and its forensic application

The three major cannabinoids, Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD) and cannabinol (CBN) were identified and determined quantitatively using a GCD (GC–EI) instrument, in samples of illicit herbal cannabis, seized by Customs and Police authorities in two areas of Greece (Ipiros and Lakonia) during 1996. These samples were sent by the above authorities to the Department of Forensic Medicine and Toxicology, University of Athens, for forensic chemical analysis. The cannabinoid content of these samples led to the classification of cannabis into two chemical phenotypes and to the differentiation of resinous and textile plants by using three different classification indexes. The cannabinoid content of cannabis plants is of forensic value in determining the geographical origin of cannabis samples, since it can be used for their classification, allocating this way the area of cultivation of the relative plants. The forensic aspects of cannabis classification are discussed.     

Fast confirmation of 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in urine by LC/MS/MS using negative atmospheric-pressure chemical ionisation (APCI)

A fast method using automated solid-phase extraction (SPE) and short-column liquid-chromatography coupled to tandem mass-spectrometry (LC/MS/MS) with negative atmospheric-pressure chemical ionisation (APCI) has been developed for the confirmation of 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in urine samples. This highly specific method which combines chromatographic separation and MS/MS-analysis can be used for the confirmation of positive immunoassay results with a NIDA cut-off of 15ng/ml. The conjugates of THC-COOH were hydrolysed prior to SPE, and a standard SPE was performed using C18-SPE columns. No derivatisation of the extracts was needed as in GC/MS analysis, and the LC run-time was 6.5min by gradient elution with a retention time of 2.4min. Linearity of calibration was obtained in the range between 0 and 500ng/ml (correlation coefficient R(2)=0.998). Using linear regression (0-50ng/ml) the limit of detection (LOD) was 2.0ng/ml and the limit of quantitation (LOQ) was 5.1ng/ml; day-to-day reproducibility and precision were tested at 15 and 250ng/ml and were 13.4ng/ml+/-3.3% and 255.8ng/ml+/-4.5%, respectively.     

Cannabinoids determination in oral fluid by SPME–GC/MS and UHPLC–MS/MS and its application on suspected drivers

The confirmation of Δ9-tetrahydrocannabinol (THC) in oral fluid (OF) is an important issue for assessing Driving Under the Influence of Drugs (DUID). The aim of this research was to develop a highly sensitive method with minimal sample pre-treatment suitable for the analysis of small OF volumes (100 μL) for the confirmation of cannabinoids in DUID cases. Two methods were compared for the confirmation of THC in residual OF samples, obtained from a preliminary on-site screening with commercial devices. An ultra high performance LC–MS (UHPLC–MS/MS) method and an SPME–GC/MS method were hence developed. 100 μL of the residual mixture OF/preservative buffer or neat OF was simply added to 10 μL of THC-D3 (1 μg/mL) and submitted to the two different analyses: A — direct injection of 10 μL in UHPLC–MS/MS in positive electrospray ionisation (ESI) mode and B — sampling for 30 min with SPME (100 μm polydimethylsiloxane or PDMS fibre) and direct injection by desorption of the fibre in the GC injection port.The lowest limit of detection (LLOD) of THC was 2 ng/mL in UHPLC–MS/MS and 0.5 ng/mL in SPME–GC/MS. In addition, cannabidiol (CBD) and cannabinol (CBN) could be detected in GC/MS equipment at 2 ng/mL, whilst in UHPLC–MS/MS the LLOD was 20 ng/mL.Both methods were applied to 70 samples coming from roadside tests. By SPME–GC/MS analysis, THC was confirmed in 42 samples, whilst CBD was detected in 21 of them, along with CBN in 14 samples. THC concentrations ranged from traces below the lowest limit of quantification or LLOQ (2 ng/mL) up to 690 ng/mL.     

Extraction and isolation of cannabinoids from marijuana seizures and characterization by 1H NMR allied to chemometric tools

Marijuana, a drug derived from the Cannabis sativa L. plant, is the world's most consumed illicit drug. In this paper, a total of 156 marijuana samples seized in the state of Espírito Santo (ES), Brazil were studied and analysed by proton nuclear magnetic resonance (¹H NMR) spectroscopy to identify the major cannabinoids present. A crude extract of all samples was purified using high performance liquid chromatography so that these compounds could serve as reference substances. Nine fractions were obtained and analysed by ¹H NMR and gas chromatography–mass spectrometry (GC–MS), with five presented cannabinoids. ?⁹-THC (Δ⁹-trans-tetrahydrocannabinol), ?⁹-THCA (?⁹-tetrahydrocannabinolic acid), ?⁸-THC (?⁸-tetrahydrocannabinol), 11-hydroxycannabinol, CBV (cannabivarin), and CBN (cannabinol) were found, and their chemical structures were confirmed by GC–MS. The latter compound was obtained with high purity (≈100%), while the others were obtained as less complex mixtures with purity higher than 75% (except for Δ⁸-THC). Principal component analysis (PCA) was used on the ¹H NMR spectra of the 156 samples, and it was found that the samples were grouped according to the months, differentiating into two groups (from July 2014 to January 2015 and from February 2015 to July 2015), where non-grouping was observed from four macro-regions of the ES state (North, Central, Metropolitan, and South). The chemical profile of the seized samples was correlated to the ¹H NMR spectrum of an isolated CBN sub-fraction, in which the group formed by samples seized in the year 2015 presented lower CBN content in the chemical composition. From the PCA score plot, two groups of samples were confirmed using the partial least squares discriminant analysis and orthogonal projections to latent structures classification methods.     

Confirmation of Syva enzyme multiple immunoassay technique (EMIT) d.a.u. and Roche Abuscreen radioimmunoassay (RIA) (125I) urine cannabinoid immunoassays by gas chromatographic/mass spectrometric (GC/MS) and bonded-phase adsorption/thin-layer chromatographic (BPA-TLC) methods

Thirty human urines screened positive by the Syva enzyme multiple immunoassay technique (EMIT) d.a.u. urine cannabinoid assay were also positive for the major marijuana urinary metabolite 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) when assayed by gas chromatographic/mass spectrometric (GC/MS) and a noninstrumental qualitative bonded-phase adsorption/thin-layer chromatographic (BPA-TLC) technique. The noninstrumental BPA-TLC procedure was the simpler of the two techniques to perform and interpret. Assay of these same samples by the Roche Abuscreen radioimmunoassay (RIA) for cannabinoids (125I) revealed that reliance on the 100-ng/mL equivalent positive calibrator yielded a high incidence of false negative results (10 out of 30). The performance of these same 4 assays on 30 true negatives also was evaluated. All samples were negative for cannabinoids by EMIT and RIA, and for THC-COOH by BPA-TLC. GC/MS assay, however, detected spurious low levels of approximately 5-ng/mL THC-COOH in two instances. Because of this, a reliability level of 10 ng/mL was set for the routine quantitative confirmation of THC-COOH by the GC/MS method.     

Potency of delta 9-THC and other cannabinoids in cannabis in England in 2005: implications for psychoactivity and pharmacology

Gas chromatography was used to study the cannabinoid content ("potency") of illicit cannabis seized by police in England in 2004/5. Of the four hundred and fifty two samples, indoor-grown unpollinated female cannabis ("sinsemilla") was the most frequent form, followed by resin (hashish) and imported outdoor-grown herbal cannabis (marijuana). The content of the psychoactive cannabinoid delta 9-tetrahydrocannabinol (THC) varied widely. The median THC content of herbal cannabis and resin was 2.1% and 3.5%, respectively. The median 13.9% THC content of sinsemilla was significantly higher than that recorded in the UK in 1996/8. In sinsemilla and imported herbal cannabis, the content of the antipsychotic cannabinoid cannabidiol (CBD) was extremely low. In resin, however, the average CBD content exceeded that of THC, and the relative proportions of the two cannabinoids varied widely between samples. The increases in average THC content and relative popularity of sinsemilla cannabis, combined with the absence of the anti-psychotic cannabinoid CBD, suggest that the current trends in cannabis use pose an increasing risk to those users susceptible to the harmful psychological effects associated with high doses of THC.