Concentrations of delta9-tetrahydrocannabinol and 11-nor-9-carboxytetrahydrocannabinol in blood and urine after passive exposure to Cannabis smoke in a coffee shop

Complexity of Translating Analytics to Recent Cannabis Use and Impairment

While current analytical methodologies can readily identify cannabis use, definitively establishing recent use within the impairment window has proven to be far more complex, requiring a new approach. Recent studies have shown no direct relationship between impairment and Δ9-tetra-hydrocannabinol (Δ9-THC) concentrations in blood or saliva, making legal "per se" Δ9-THC limits scientifically unjustified. Current methods that focus on Δ9-THC and/or metabolite concentrations in blood, saliva, urine, or exhaled breath can lead to false-positive results for recent use due to the persistence of Δ9-THC well outside of the typical 3-4 h window of potential impairment following cannabis inhalation. There is also the issue of impairment due to other intoxicating substances-just because a subject exhibits signs of impairment and cannabis use is detected does not rule out the involvement of other drugs. Compounding the matter is the increasing popularity of hemp-derived cannabidiol (CBD) products following passage of the 2018 Farm Bill, which legalized industrial hemp in the United States. Many of these products contain varying levels of Δ9-THC, which can lead to false-positive tests for cannabis use. Furthermore, hemp-derived CBD is used to synthesize Δ8-THC, which possesses psychoactive properties similar to Δ9-THC and is surrounded by legal controversy. For accuracy, analytical methods must be able to distinguish the various THC isomers, which have identical masses and exhibit immunological cross-reactivity. A new testing approach has been developed based on exhaled breath and blood sampling that incorporates kinetic changes and the presence of key cannabinoids to detect recent cannabis use within the impairment window without the false-positive results seen with other methods. The complexity of determining recent cannabis use that may lead to impairment demands such a comprehensive method so that irresponsible users can be accurately detected without falsely accusing responsible users who may unjustly suffer harsh, life-changing consequences.

Chronic Administration of Δ9-Tetrahydrocannabinol Alters Brain Glucose Uptake and Improves Waiting Impulsivity in the Rat

Introduction: Δ9-Tetrahydrocannabinol (THC) acts as an agonist at cannabinoid receptors. Its chronic intake affects many behaviors, including cognitive processes. The aims of this study in rats are to assess the chronic effects of THC on impulsivity and on regional brain glucose uptake. Materials and Methods: For the determination of "waiting impulsivity," a total of 20 male Lister Hooded rats were trained to perform a reaction time task, followed by a baseline test of impulsivity and baseline glucose uptake measurements with [18F]-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). Then, 10 rats each received 3 mg/kg THC or vehicle injected intraperitoneally daily for 21 days. Subsequently, a second behavioral test and PET measurements were performed, and blood THC concentrations were determined. Analyses of variance of brain regions of the impulsivity network with the parameter "standardized uptake value" regarding glucose uptake and correlation analyses of the collected parameters were carried out. Discussion: After chronic THC treatment, decreased glucose uptake (p-values <0.05) was found in cingulate cortex, hippocampus, amygdala, thalamus, and cerebellar cortex, as compared with vehicle-treated rats. The number of correct no-go responses (increased waiting time) significantly increased (p<0.05) in THC-treated rats. Furthermore, correct no-go responses correlated positively and strongly with the THC blood concentrations (Spearman's ρ=0.79, p<0.01). Conclusion: These findings reflect a specific reduction in impulsive behavior after chronic THC treatment, showing a functionally relevant influence of THC on "waiting impulsivity" with reduced selective glucose uptake at the same time.

Detection of Cannabinoids in Oral Fluid Specimens as the Preferred Biological Matrix for a Point-of-Care Biosensor Diagnostic Device

An increasing number of countries have started to decriminalize or legalize the consumption of cannabis for recreational and medical purposes. The active ingredients in cannabis, termed cannabinoids, affect multiple functions in the human body, including coordination, motor skills, memory, response time to external stimuli, and even judgment. Cannabinoids are a unique class of terpeno-phenolic compounds, with 120 molecules discovered so far. There are certain situations when people under the influence of cannabis may be a risk to themselves or the public safety. Over the past two decades, there has been a growing research interest in detecting cannabinoids from various biological matrices. There is a need to develop a rapid, accurate, and reliable method of detecting cannabinoids in oral fluid as it can reveal the recent intake in comparison with urine specimens, which only show a history of consumption. Significant improvements are continuously made in the analytical formats of various technologies, mainly concerning improving their sensitivity, miniaturization, and making them more user-friendly. Additionally, sample collection and pretreatment have been extensively studied, and specific devices for collecting oral fluid specimens have been perfected to allow rapid and effective sample collection. This review presents the recent findings regarding the use of oral fluid specimens as the preferred biological matrix for cannabinoid detection in a point-of-care biosensor diagnostic device. A critical review is presented, discussing the findings from a collection of review and research articles, as well as publicly available data from companies that manufacture oral fluid screening devices. Firstly, the various conventional methods used to detect cannabinoids in biological matrices are presented. Secondly, the detection of cannabinoids using point-of-care biosensors is discussed, emphasizing oral fluid specimens. This review presents the current pressing technological challenges and highlights the gaps where new technological solutions can be implemented.

The legalization of cannabis may result in increased indoor exposure to Δ9-tetrahydrocannabinol

Cannabis is a genus of plants in the Cannabaceae family that contains tetrahydrocannabinolic acid. When heated or burned, the acid decarboxylates to form tetrahydrocannabinol (THC). Its (-)-trans-Δ9-THC isomer is a psychoactive substance that has been used as a drug for centuries. In most countries, both the private sale of cannabis products and their use for non-medical purposes are still prohibited by law. However, for some time now there has been societal and political pressure to at least partially legalize cannabis products. It can be expected that such a measure will lead to a significant increase in the consumption of cannabis. However, this also increases the possibility of involuntary passive exposure to THC and contamination of the indoor environment. In indoor sciences, THC is still a largely unknown or underrepresented substance. In this perspective paper, THC will therefore first be presented on the basis of its physical properties. Then, the distribution of THC in different indoor compartments and potential routes of passive exposure are discussed. Finally, an assessment of the future importance of THC for indoor use is made. Previous experience has shown that early monitoring is always advantageous so that preventive and protective measures can be taken quickly if necessary.

False-Negative Confirmatory Testing in Patients With Cannabinoid-Positive Urine Drug Screens

This cross-sectional study discusses false-negative results associated with a change in the reporting threshold of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol.

Electrochemical Oxidation of Δ9-Tetrahydrocannabinol at Nanomolar Concentrations

With increasing marijuana legalization, there is a growing need for technology that can determine if an individual is impaired due to recent marijuana usage. The electrochemical oxidation of Δ9-THC to form its corresponding quinones can be used as a framework to develop an electrochemical sensor for Δ9-THC. This study describes an electrochemical oxidation of Δ9-THC that uses a copper anode, a platinum cathode, and an atmosphere of oxygen. The oxidation is feasible at nanomolar concentrations, which approaches the reactivity that is necessary for developing a real-world marijuana breathalyzer. Moreover, we show that vaporized Δ9-THC can be captured directly in an electrolyte medium and subjected to electrochemical oxidation, thus paving the way for use in future technology development.

Determination of cannabinoids in human cerumen samples by use of UPLC-MS/MS as a potential biomarker for drug use

A quantitative analytical procedure was developed and validated by the use of Ultra- Performance Liquid Chromatography tandem Mass Spectrometry (UPLC-MS/MS) for the determination of Cannabidiol (CBD), Cannabinol (CBN), Δ⁹-Tetrahydrocannabinol (Δ⁹-THC), Cannabichromene (CBC), Cannabigerol (CBG) and 11-Nor- 9- Carboxy- Tetrahydrocannabinol (THC-COOH) in an unconventional biological matrix, cerumen. All the investigated calibration curves were characterized by high correlation values (R² ≥ 0.9965). The LODs and LOQs ranged from 0.004 to 0.009 μg g^-1 and 0.012-0.029 μg g^-1, respectively. Intra-assay and inter-assay precision were found to be 0.6-2.5%, and 0.8-2.2%, respectively. All recovery values of cannabinoids, with the use of the optimum cotton swab, at low (0.008 μg g^-1 of cerumen), medium (0.037 μg g^-1of cerumen) and high (0.16 μg g^-1 of cerumen) control levels, were estimated to be above 86%. The method developed here permitted the analysis of real cerumen samples obtained from fourteen cannabis users. In twelve out of fourteen cases, Δ⁹-THC was found to be positive, while in six cases, three major cannabinoids, CBN, CBG and Δ⁹-THC were quantified at concentrations 0.02-0.21 μg g^-1, 0.01-0.24 μg g^-1 and 0.01-4.86 μg g^-1, respectively. Subject #8 has the highest amount of the detected substances in both left and right ear, with Δ⁹-THC at a concentration of 1.85 and 4.86 μg g^-1, CBG 0.06 and 0.24 μg g^-1, CBN 0.10 and 0.21 μg g^-1, respectively. In addition, a detection window for the substances Δ⁹-Tetrahydrocannabinol, Cannabinol and Cannabigerol, in cerumen, was defined with success. In this case, Δ⁹-THC reached a maximum detection frame of up to fifteen days after smoking 0.5 g of marijuana cigarette. ANOVA-one-way analysis also indicated that the average earwax production of non-cannabis users differs significantly from the one of cannabis users (p = 0.048, <0.05). On the other hand, no significant difference was noticed between male and female users as the p value exceeded 0.05. In addition, no significant effect was observed on earwax production in regard to age, frequency and the last time of use (p > 0.05). These last three factors proved to have a significant impact on cannabinoids concentrations, since p values were less than 0.05.

A Cannabinoid Fuel Cell Capable of Producing Current by Oxidizing Δ9-Tetrahydrocannabinol

We report the development of a current-producing H-Cell that relies on the oxidation of Δ⁹-tetrahydrocannabinol (THC), which is the primary psychoactive ingredient in marijuana. We found through systematic investigation of several variables that power densities could be improved 5-fold. Moreover, a real-time signal in a rudimentary THC sensor was observed at varying concentrations of THC. Given the growing societal interest in the detection of THC, our studies lay the foundation for the development of a marijuana breathalyzer.

A rapid assay provides on-site quantification of tetrahydrocannabinol in oral fluid

[Figure: see text].

Sensitivity, Specificity and Accuracy of a Novel EEG-Based Objective Test, the Cognalyzer®, in Detecting Cannabis Psychoactive Effects

Introduction

Current standards for identifying recent cannabis use are based on body fluid testing. The Cognalyzer^® is a novel electroencephalography (EEG) measurement device and algorithm designed to objectively characterize brainwave alterations associated with cannabis. The objective of this study was to assess the accuracy, sensitivity and specificity levels of the Cognalyzer^® to characterize brainwave alterations following cannabis inhalation.

Methods

Seventy-five participants, aged 19–55 years, were enrolled, and oral fluid samples were collected pre-cannabis inhalation. EEG and subjective drug effects questionnaire (DEQ) were administered pre- and post-ad libitum cannabis inhalation. Fifty participants remained in the clinic for 4 h post-inhalation. Blinded analyses of the EEG files were conducted by Zentrela Inc. using two versions (V1 and V2) of the Cognalyzer^® algorithm.

Pre- vs. post-inhalation comparison status was characterized by the Cognalyzer^® and summarized for: sensitivity, specificity, accuracy, percent false positive, percent false negative and positive and negative predictive value. The null hypothesis was tested using McNemar’s test. Cognalyzer^® results pre- and post-inhalation were combined with the oral fluid tetrahydrocannabinol (THC) concentration to evaluate potential to improve current drug testing.

Results

The two versions of the Cognalyzer^® algorithm had similar diagnostic results. Diagnostic outcomes were improved when participants with missing EEG recordings or electrode placement errors were removed. The Cognalyzer^® accuracy was 85.5% and 83.9%, sensitivity was 87.1% and 88.7%, and specificity was 83.9% and 79.0% for algorithm V1 and V2, respectively. Combining Cognalyzer^® results with oral fluid concentrations reduced false-positive oral fluid test results by up to 49%.

Conclusion

The Cognalyzer^® characterized brainwave alterations associated with cannabis inhalation with high levels of accuracy in a population of participants with varied cannabis inhalation histories, relative to the comparison standard of pre- vs. post-inhalation status. The Cognalyzer^® allows the results to be generalized to the larger population addressing a limitation in currently accepted standards.

Assessing the prevalence and correlates of prenatal cannabis consumption in an urban Canadian population: a cross-sectional survey

BACKGROUND

Recreational cannabis use was legalized in Canada in October 2018. We aimed to determine the prevalence and correlates of cannabis consumption among pregnant individuals in a single Canadian city following national legalization.

METHODS

Over the period May to October 2019, we distributed an anonymous cross-sectional survey to pregnant patients attending family practice, midwifery, and low-risk and high-risk obstetrics clinics in Hamilton, Ontario. Eligibility was based on English literacy and current pregnancy. The survey included questions regarding lifetime and in-pregnancy cannabis use, intent for postpartum use and patterns of use. We also collected demographic information. We calculated descriptive statistics and performed logistic regression analyses to explore the relations between cannabis consumption and demographic characteristics.

RESULTS

Of 531 pregnant individuals approached, 478 agreed and were able to participate, for a 90% participation rate. Among these 478 respondents, 54 (11%) reported consuming cannabis at some point during the pregnancy and 20 (4%) reported currently consuming cannabis. Among the 460 respondents who intended to breastfeed, 23 (5%) planned to consume cannabis during the postpartum period. Of 20 current users, 13 (65%) reported consuming cannabis at least weekly and 19 (95%) reported nausea, sleep problems or anxiety as reasons for use. Respondents without postsecondary education had 10.0-fold (95% confidence interval [CI] 4.6-23.5) greater odds of prenatal cannabis consumption than university-educated respondents. In addition, respondents who reported that their partners used cannabis had 3.9-fold (95% CI 2.2-7.3) greater odds of prenatal cannabis consumption than those who reported that their partners did not use cannabis.

INTERPRETATION

Lower educational attainment and partners' cannabis consumption were associated with greater odds of inpregnancy cannabis use. These results may help to inform early intervention strategies to decrease cannabis consumption during this vulnerable period of fetal and neonatal development.

Identifying and Quantifying Cannabinoids in Biological Matrices in the Medical and Legal Cannabis Era

Background

Cannabinoid analyses generally included, until recently, the primary psychoactive cannabis compound, Δ9-tetrahydrocannabinol (THC), and/or its inactive metabolite, 11-nor-9-carboxy-THC, in blood, plasma, and urine. Technological advances revolutionized the analyses of major and minor phytocannabinoids in diverse biological fluids and tissues. An extensive literature search was conducted in PubMed for articles on cannabinoid analyses from 2000 through 2019. References in acquired manuscripts were also searched for additional articles.

Content

This article summarizes analytical methodologies for identification and quantification of multiple phytocannabinoids (including THC, cannabidiol, cannabigerol, and cannabichromene) and their precursors and/or metabolites in blood, plasma, serum, urine, oral fluid, hair, breath, sweat, dried blood spots, postmortem matrices, breast milk, meconium, and umbilical cord since the year 2000. Tables of nearly 200 studies outline parameters including analytes, specimen volume, instrumentation, and limits of quantification. Important diagnostic and interpretative challenges of cannabinoid analyses are also described. Medicalization and legalization of cannabis and the 2018 Agricultural Improvement Act increased demand for cannabinoid analyses for therapeutic drug monitoring, emergency toxicology, workplace and pain-management drug testing programs, and clinical and forensic toxicology applications. This demand is expected to intensify in the near future, with advances in instrumentation performance, increasing LC-MS/MS availability in clinical and forensic toxicology laboratories, and the ever-expanding knowledge of the potential therapeutic use and toxicity of phytocannabinoids.

Summary

Cannabinoid analyses and data interpretation are complex; however, major and minor phytocannabinoid detection windows and expected concentration ranges in diverse biological matrices improve the interpretation of cannabinoid test results.

Selective sensing of THC and related metabolites in biofluids by host:guest arrays

A host–guest fluorescence sensor array can selectively detect THC and its metabolites in biofluids such as urine and saliva.

Surface Detection of THC Attributable to Vaporizer Use in the Indoor Environment

The number of cannabis users increased up to 188 million users worldwide in 2017. Smoking and vaping are the most common consumption routes with formation of side-stream smoke/vapor and secondhand exposure to cannabinoids has been described in the literature. External contamination of hair by cannabis smoke has been studied but there are no studies on third-hand cannabis exposure due to deposition of smoke or vapor on surfaces. We tested whether cannabinoids could be detected on surfaces and objects in a room where cannabis is vaporized. Surface samples were collected using isopropanol imbued non-woven wipes from hard surfaces and objects. Each surface was swabbed three times with standardized swabbing protocol including three different patterns. Samples were analyzed using LC-ESI-MS/MS in combination with online extraction. THC was detected on 6 samples out of the 15 collected in the study room at quantifiable levels ranging 348-4882 ng/m². Negative control samples collected from areas outside the study room were all negative. We demonstrated that surfaces exposed to side-stream cannabis vapor are positive for THC at quantifiable levels. This study represents a first step in understanding how side-stream cannabis vapor deposits in the environment and potentially results in a tertiary exposure for users and non-users.

Prenatal Marijuana Use by Self-Report and Umbilical Cord Sampling in a State With Marijuana Legalization

OBJECTIVE

To compare self-reported maternal marijuana use with quantitative biological sampling for a marijuana metabolite, 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid, in umbilical cord homogenate in a state with legalized marijuana.

METHODS

We conducted a cross-sectional study of women approached at the time of admission for delivery with live, singleton pregnancies at 24 weeks of gestation or greater at two urban medical centers in Colorado. Maternal marijuana use was estimated by 1) report to a health care provider on admission history and physical, 2) survey of self-reported use, and 3) liquid chromatography-tandem mass spectrometry analysis of umbilical cord homogenate for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid. Women were categorized by survey-reported last use (30 days ago or less, 30 days to 1 year, more than 1 year, never) and proportion of women with cord results above the limit of detection and limit of quantification for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid was reported for each group. Comparisons between groups were made using contingency tables. Correlation between survey-reported frequency of use and quantitative 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid cord homogenate results was evaluated.

RESULTS

We included 116 women with self-report surveys linked to cord assay results. Six percent (95% CI 2.5-12.0%) of participants reported use in the past 30 days on survey and 2.6% (95% CI 0.5-7.4%) of participants reported marijuana use to health care providers. On umbilical cord assay, 22.4% (95% CI 15.2-31.1%) had detectable 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid. The proportion of women with detectable 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid increased with more recent self-reported use. Survey-reported frequency of use in the past 30 days had moderate correlation with quantified umbilical cord 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (correlation coefficient 0.44, 95% CI 0.28-0.58, P<.001).

CONCLUSION

Umbilical cord sampling results in higher estimates of prenatal marijuana use than self-report even in the setting of legalization. Umbilical cord assays for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid demonstrate promise for quantifying use. Future studies should examine how the use of biological sampling informs the association between marijuana use and perinatal outcomes.

Common Substances of Abuse

Adolescent substance abuse remains common, with almost a third of adolescents admitting to ethanol use, and a quarter admitting to illicit drug use. It is essential for pediatricians to regularly screen adolescent patients for substance use, because early initiation of drug use has been associated with physical, behavioral, and social health risks. Adolescents abuse what is common and readily available; this includes ethanol, over-the-counter products, marijuana, and inhalants. The most common and effective clinical treatments for significant toxicity from substances of abuse is symptomatic and supportive care including hemodynamic support, respiratory support, and sedation to control psychomotor agitation.

Health effects of exposure to second- and third-hand marijuana smoke: a systematic review

BACKGROUND

Recreational marijuana has been legalized in 11 jurisdictions; Canada will legalize marijuana by July 2018. With this changing landscape, there is a need to understand the public health risks associated with marijuana to support patient-care provider conversations, harm-reduction measures and evidence-informed policy. The objective of this work was to summarize the health effects of exposure to second- and third-hand marijuana smoke.

METHODS

In this systematic review, we searched 6 databases from inception to October 2017. Abstract and full-text review was conducted in duplicate. Studies were included if they were human, in vivo or in vitro studies with more than 1 case reported in English or French, and reported original, quantitative data. Three outcomes were extracted: 1) cannabinoids and cannabinoid metabolites in bodily fluids, 2) self-reported psychoactive effects and 3) eye irritation and discomfort.

RESULTS

Of the 1701 abstracts identified, 60 proceeded to full-text review; the final data set contained 15 articles. All of the included studies were of good to poor quality as assessed with the Downs and Black checklist. There is evidence of a direct relation between the tetrahydrocannabinol content of marijuana and effects on those passively exposed. This relation is mediated by several environmental factors including the amount of smoke, ventilation, air volume, number of marijuana cigarettes lit and number of smokers present. No evidence was identified assessing exposure to third-hand marijuana smoke or the health effects of long-term exposure.

INTERPRETATION

Exposure to second-hand marijuana smoke leads to cannabinoid metabolites in bodily fluids, and people experience psychoactive effects after such exposure. Alignment of tobacco and marijuana smoking bylaws may result in the most effective public policies. More research is required to understand the impact of exposure to third-hand smoke and the health effects of long-term exposure to second-hand smoke.

Effects of tetrahydrocannabinol on glucose uptake in the rat brain

Δ⁹-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain. The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain. 21 male Sprague Dawley rats (12-13 w) were examined and received five different doses of THC ranging from 0.01 to 1 mg/kg. For data acquisition a Focus 120 small animal PET scanner was used and 24.1-28.0 MBq of [¹⁸F]-fluoro-2-deoxy-d-glucose were injected. The data were acquired for 70 min and arterial blood samples were collected throughout the scan. THC, THC-OH and THC-COOH were determined at 55 min p.i. Nine volumes of interest were defined, and the cerebral glucose uptake was calculated for each brain region. Low blood THC levels of < 1 ng/ml (injected dose: ≤ 0.01 mg/kg) corresponded to an increased glucose uptake (6-30 %), particularly in the hypothalamus (p = 0.007), while blood THC levels > 10 ng/ml (injected dose: ≥ 0.05 mg/kg) coincided with a decreased glucose uptake (-2 to -22 %), especially in the cerebellar cortex (p = 0.008). The effective concentration in this region was estimated 2.4 ng/ml. This glucose PET study showed that stimulation of CB1 receptors by THC affects the glucose uptake in the rat brain, whereby the effect of THC is regionally different and dependent on dose - an effect that may be of relevance in behavioural studies.

Traversing the triangulum: the intersection of tobacco, legalised marijuana and electronic vaporisers in Denver, Colorado

OBJECTIVE

To explore the intersection of tobacco, legalised marijuana and electronic vaporiser use among young adults in the 'natural laboratory' of Colorado, the first state with legalised retail marijuana.

METHODS

We conducted semistructured interviews with 32 young adults (18-26 years old) in Denver, Colorado, in 2015 to understand the beliefs and practices related to the use of tobacco, marijuana and vaporisers.

RESULTS

We found ambiguity about whether the phrase 'to smoke' refers to the use of tobacco or marijuana products. Smoking marijuana blunts (emptied cigarillo or tobacco wrap filled with marijuana) was common, but few interpreted this as tobacco use. Marijuana vaporisers were used to circumvent public consumption laws (eg, while at work or when driving). Young adults considered secondhand tobacco smoke dangerous, but perceived secondhand marijuana smoke as benign.

DISCUSSION

Using tobacco products as a delivery method for marijuana (eg, blunts) might be increasing and normalising tobacco use among young adults. Surveillance should explicitly ask about use of tobacco products for marijuana. Marijuana vaporisers, often indistinguishable from nicotine vaporisers, may be used to circumvent public consumption laws; communities concerned about use of marijuana in public spaces should include vaporisers (for nicotine or marijuana) in smoke-free regulations. Tobacco, marijuana and electronic vaporisers should be studied together, rather than separately. This approach is essential in informing research and policy as more US states and countries worldwide move to legalise marijuana.

Development and validation of an automated liquid-liquid extraction GC/MS method for the determination of THC, 11-OH-THC, and free THC-carboxylic acid (THC-COOH) from blood serum

The analysis of Δ⁹-tetrahydrocannabinol (THC) and its metabolites 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH) from blood serum is a routine task in forensic toxicology laboratories. For examination of consumption habits, the concentration of the phase I metabolite THC-COOH is used. Recommendations for interpretation of analysis values in medical-psychological assessments (regranting of driver’s licenses, Germany) include threshold values for the free, unconjugated THC-COOH. Using a fully automated two-step liquid-liquid extraction, THC, 11-OH-THC, and free, unconjugated THC-COOH were extracted from blood serum, silylated with N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), and analyzed by GC/MS. The automation was carried out by an x-y-z sample robot equipped with modules for shaking, centrifugation, and solvent evaporation. This method was based on a previously developed manual sample preparation method. Validation guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh) were fulfilled for both methods, at which the focus of this article is the automated one. Limits of detection and quantification for THC were 0.3 and 0.6 μg/L, for 11-OH-THC were 0.1 and 0.8 μg/L, and for THC-COOH were 0.3 and 1.1 μg/L, when extracting only 0.5 mL of blood serum. Therefore, the required limit of quantification for THC of 1 μg/L in driving under the influence of cannabis cases in Germany (and other countries) can be reached and the method can be employed in that context. Real and external control samples were analyzed, and a round robin test was passed successfully. To date, the method is employed in the Institute of Legal Medicine in Giessen, Germany, in daily routine. Automation helps in avoiding errors during sample preparation and reduces the workload of the laboratory personnel. Due to its flexibility, the analysis system can be employed for other liquid-liquid extractions as well. To the best of our knowledge, this is the first publication on a comprehensively automated classical liquid-liquid extraction workflow in the field of forensic toxicological analysis.

Graphical abstract

Water-compatible imprinted pills for sensitive determination of cannabinoids in urine and oral fluid

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in urine and oral fluid (OF). The composition of the molecular imprinted polymer (MIP) was optimized based on the screening results of a non-imprinted polymer library (NIP-library). Thus, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker were selected for the preparation of the MIP, using catechin as a mimic template. MISPE pills were incubated with 0.5 mL urine or OF sample for adsorption of analytes. For desorption, the pills were transferred to a vial with 2 mL of methanol:acetic acid (4:1) and sonicated for 15 min. The elution solvent was evaporated and reconstituted in methanol:formic acid (0.1%) 50:50 to inject in LC-MS/MS. The developed method was linear over the range from 1 to 500 ng mL(-1) in urine and from 0.75 to 500 ng mL(-1) in OF for all four analytes. Intra- and inter-day imprecision were <15%. Extraction recovery was 50-111%, process efficiency 15.4-54.5% and matrix effect ranged from -78.0 to -6.1%. Finally, the optimized and validated method was applied to 4 urine and 5 OF specimens. This is the first method for the determination of THC, THC-COOH, CBN and CBD in urine and OF using MISPE technology.

Finding cannabinoids in hair does not prove cannabis consumption

Hair analysis for cannabinoids is extensively applied in workplace drug testing and in child protection cases, although valid data on incorporation of the main analytical targets, ∆9-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-THC (THC-COOH), into human hair is widely missing. Furthermore, ∆9-tetrahydrocannabinolic acid A (THCA-A), the biogenetic precursor of THC, is found in the hair of persons who solely handled cannabis material. In the light of the serious consequences of positive test results the mechanisms of drug incorporation into hair urgently need scientific evaluation. Here we show that neither THC nor THCA-A are incorporated into human hair in relevant amounts after systemic uptake. THC-COOH, which is considered an incontestable proof of THC uptake according to the current scientific doctrine, was found in hair, but was also present in older hair segments, which already grew before the oral THC intake and in sebum/sweat samples. Our studies show that all three cannabinoids can be present in hair of non-consuming individuals because of transfer through cannabis consumers, via their hands, their sebum/sweat, or cannabis smoke. This is of concern for e.g. child-custody cases as cannabinoid findings in a child’s hair may be caused by close contact to cannabis consumers rather than by inhalation of side-stream smoke.

What Can a Urine Drug Screening Immunoassay Really Tell Us?

Urine drug screening has become standard of care in many medical practice settings to assess compliance, detect misuse, and/or to provide basis for medical or legal action. The antibody-based enzymatic immunoassays used for qualitative analysis of urine have significant drawbacks that clinicians are often not aware of. Recent literature suggests that there is a lack of understanding of the shortcomings of these assays by clinicians who are ordering and/or interpreting them. This article addresses the state of each of the individual immunoassays that are most commonly used today in order to help the reader become proficient in the interpretation and application of the results. Some literature already exists regarding sources of "false positives" and "false negatives," but none seem to present the material with the practicing clinician in mind. This review aims to avoid overwhelming the reader with structures and analytical chemistry. The reader will be presented relevant clinical knowledge that will facilitate appropriate interpretation of immunoassays regardless of practice settings. Using this review as a learning tool and a reference, clinicians will be able to interpret the results of commonly used immunoassays in an evidence-based, informed manner and minimize the negative impact that misinterpretation has on patient care.

Non-smoker exposure to secondhand cannabis smoke. I. Urine screening and confirmation results

Increased cannabis potency has renewed concerns that secondhand exposure to cannabis smoke can produce positive drug tests. A systematic study was conducted of smoke exposure on drug-free participants. Six experienced cannabis users smoked cannabis cigarettes (5.3% THC in Session 1 and 11.3% THC in Sessions 2 and 3) in a sealed chamber. Six non-smokers were seated with smokers in an alternating manner. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Non-smoking participant specimens (collected 0-34 h) were analyzed with four immunoassays at different cutoff concentrations (20, 50, 75 and 100 ng/mL) and by GC-MS (LOQ = 0.75 ng/mL). No presumptive positives occurred for non-smokers at 100 and 75 ng/mL; a single positive occurred at 50 ng/mL; and multiple positives occurred at 20 ng/mL. Maximum THCCOOH concentrations by GC-MS for non-smokers ranged from 1.3 to 57.5 ng/mL. THCCOOH concentrations generally increased with THC potency, but room ventilation substantially reduced exposure levels. These results demonstrate that extreme cannabis smoke exposure can produce positive urine tests at commonly utilized cutoff concentrations. However, positive tests are likely to be rare, limited to the hours immediately post-exposure, and occur only under environmental circumstances where exposure is obvious.

Cannabinoids in oral fluid following passive exposure to marijuana smoke

The concentration of tetrahydrocannabinol (THC) and its main metabolite 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) as well as cannabinol (CBN), and cannabidiol (CBD) were measured in oral fluid following realistic exposure to marijuana in a Dutch coffee-shop. Ten healthy subjects, who were not marijuana smokers, volunteered to spend 3h in two different coffee shops in Groningen, The Netherlands. Subjects gave two oral fluid specimens at each time point: before entering the store, after 20 min, 40 min, 1h, 2h, and 3h of exposure. The specimens were collected outside the shop. Volunteers left the shop completely after 3h and also provided specimens approximately 12-22 h after beginning the exposure. The oral fluid specimens were subjected to immunoassay screening; confirmation for THC, cannabinol and cannabidiol using GC/MS; and THC-COOH using two-dimensional GC-GC/MS. THC was detectable in all oral fluid specimens taken 3h after exposure to smoke from recreationally used marijuana. In 50% of the volunteers, the concentration at the 3h time-point exceeded 4 ng/mL of THC, which is the current recommended cut-off concentration for immunoassay screening; the concentration of THC in 70% of the oral fluid specimens exceeded 2 ng/mL, currently proposed as the confirmatory cut-off concentration. THC-COOH was not detected in any specimens from passively exposed individuals. Therefore it is recommended that in order to avoid false positive oral fluid results assigned to marijuana use, by analyzing for only THC, the metabolite THC-COOH should also be monitored.