Determination of Cannabinoid Vapor Pressures to Aid in Vapor Phase Detection of Intoxication

Driving Under the Influence of Alcohol, Cannabis, and Delta-8 THC: Perceived Likelihood, Risk Perceptions, and Behaviors

Driving under the influence (DUI) of alcohol or cannabis poses public health risks. Little is known about DUI of Delta-8 THC, a newer cannabis product. Using 2022 survey data among 189 U.S. adults ages 18-25 (58.73% male, 59.26% non-Hispanic White), multivariable logistic regression examined substance-specific (alcohol, cannabis, Delta-8) DUI perceived likelihood and risk in relation to past-year DUI among those with past-year use of each. Overall, 72.49% reported past-year alcohol use, 50.53% cannabis, and 22.46% Delta-8. Among those reporting past-year use of each respective substance, 33.58% reported DUI of alcohol, 32.63% cannabis, and 57.14% Delta-8. On average, participants had the same DUI perceived likelihood ("somewhat unlikely") across substances and perceived alcohol DUI as riskiest. Higher alcohol DUI perceived likelihood and lower perceived risk were associated with alcohol-related DUI. Greater cannabis-related perceived likelihood (but not risk) was associated with cannabis-related DUI. Neither Delta-8 DUI perceived likelihood nor risk were associated with Delta-8 DUI. In sum, perceived DUI likelihood for alcohol, cannabis, or Delta-8 tended to be similar. Among those with past-year use of each, the proportion of DUI was highest for Delta-8. Interventions should target DUI-related perceived likelihood and promote protective behavioral strategies that reduce substance-specific DUI risk.

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.

Utilizing Different Diffusion Mechanisms for Thin Film Fluorescence-Based Detection and Discrimination of Illicit Drug Vapors

Film-based fluorescence sensors have been demonstrated to be powerful tools for real-time detection of trace chemical vapors. While explosive vapor detection via fluorescence quenching has been widely explored, fluorescence-based real-time detection and identification of illicit drug vapors remains a challenge. Here, we report two perylene diimide-based sensing materials, P1 and P2, incorporating 2,2-dihexyloctanyl chains and 4-[tris(4-{tert-butyl}phenyl)methyl]phenyl moieties at the imide positions, respectively. Quartz crystal microbalance with in situ photoluminescence measurements showed that N-methylphenethylamine, a simulant of methamphetamine (MA), diffused into films of P1 and P2 via Fickian and case-II mechanisms, respectively. The difference in the analyte diffusion mechanism led to P2 showing significantly faster luminescence quenching but slower luminescence recovery compared to P1. Finally, the different diffusion mechanisms were used as the basis for developing a simple sensor array based on P1 and P2 that could selectively detect free-base illicit drugs (MA, cocaine, and tetrahydrocannabinol) from potential interferants (organic amines, alcohol, and cosmetics) within 40 s.

Luminescence-based detection and identification of illicit drugs

Luminescence-based sensing is capable of being used for the sensitive, rapid, and in some cases selective detection of chemicals. Furthermore, the method is amenable to incorporation into handheld low-power portable detectors that can be used in the field. Luminescence-based detectors are now commercially available for explosive detection with the technology built on a strong foundation of science. In contrast, there are fewer examples of luminescence-based detection of illicit drugs, despite the pervasive and global challenge of combating their manufacture, distribution and consumption and the need for handheld detection systems. This perspective describes the relatively nascent steps that have been reported in the use of luminescent materials for the detection of illicit drugs. Much of the published work has focused on detection of illicit drugs in solution with less work on vapour detection using thin luminescent sensing films. The latter are better suited for handheld sensing devices and detection in the field. Illicit drug detection has been achieved via different mechanisms, all of which change the luminescence of the sensing material. These include photoinduced hole transfer (PHT) leading to quenching of the luminescence, disruption of Förster energy transfer between different chromophores by a drug, and chemical reaction between the sensing material and a drug. The most promising of these is PHT, which can be used for rapid and reversible detection of illicit drugs in solution and film-based sensing of drugs in the vapour phase. However, there are still significant knowledge gaps, for example, how vapours of illicit drugs interact with the sensing films, and how to achieve selectivity for specific drugs.

Vapor pressure measurements on linalool using a rapid and inexpensive method suitable for cannabis-associated terpenes†

Vapor pressure (psat) data are needed to assess the potential use of terpenes as breath markers of recent cannabis use. Herein, a recently introduced gas-saturation method for psat measurements, known as dynamic vapor microextraction (DVME), was used to measure psat for the terpene (±)-3,7-dimethylocta-1,6-dien-3-ol, commonly known as linalool. The DVME apparatus utilizes inexpensive and commercially available components, a low internal volume, and helium carrier gas to minimize nonideal mixture behavior. In the temperature range from 314 K to 354 K, DVME-based measurements of the psat of linalool ranged from 81 Pa to 1250 Pa. With a measurement period of 30 min, the combined standard uncertainty of these measurements ranged from 0.0358·psat to 0.0584·psat, depending on temperature. The DVME-based measurements agree with a Wagner correlation of available literature data. We demonstrate that DVME produces accurate results for values of psat that are 200 times higher than in the DVME validation study with n-eicosane (C20H42). The oxidative stability of linalool was improved by the addition of 0.2 mass % of the antioxidant tert-butylhydroquinone.

Dysmenorrhoea: Can Medicinal Cannabis Bring New Hope for a Collective Group of Women Suffering in Pain, Globally?

Dysmenorrhoea effects up to 90% of women of reproductive age, with medical management options including over-the-counter analgesia or hormonal contraception. There has been a recent surge in medicinal cannabis research and its analgesic properties. This paper aims to critically investigate the current research of medicinal cannabis for pain relief and to discuss its potential application to treat dysmenorrhoea. Relevant keywords, including medicinal cannabis, pain, cannabinoids, tetrahydrocannabinol, dysmenorrhoea, and clinical trial, have been searched in the PubMed, EMBASE, MEDLINE, Google Scholar, Cochrane Library (Wiley) databases and a clinical trial website (clinicaltrials.gov). To identify the relevant studies for this paper, 84 papers were reviewed and 20 were discarded as irrelevant. This review critically evaluated cannabis-based medicines and their mechanism and properties in relation to pain relief. It also tabulated all clinical trials carried out investigating medicinal cannabis for pain relief and highlighted the side effects. In addition, the safety and toxicology of medicinal cannabis and barriers to use are highlighted. Two-thirds of the clinical trials summarised confirmed positive analgesic outcomes, with major side effects reported as nausea, drowsiness, and dry mouth. In conclusion, medicinal cannabis has promising applications in the management of dysmenorrhoea. The global medical cannabis market size was valued at USD 11.0 billion in 2021 and is expected to expand at a compound annual growth rate (CAGR) of 21.06% from 2022 to 2030. This will encourage academic as well as the pharmaceutical and medical device industries to study the application of medical cannabis in unmet clinical disorders.

Application of Porous Layer Open Tubular Columns: Beyond Permanent Gases

Porous layer open tubular (PLOT) columns are traditionally built with particles that are adhered to the tubing walls. These columns have unique selectivity and provide a great alternative when gaseous samples need to be separated, but these columns also have been used to separate higher boiling point analytes. There are many different commercially available stationary phases of PLOT columns, including alumina-based columns, molecular sieves, and porous polymers. Alumina-based columns have an aluminum oxide stationary phase that is then deactivated with different salts. These columns have high capacity, superior loading ability, and produce symmetrical peaks. Molecular sieve columns are designed specifically for permanent gas separations because the columns have high retention. Porous polymer columns are highly hydrophobic, making them more applicable to analyzing a wider range of samples.

Vapor Pressure, Vaping, and Corrections to Misconceptions Related to Medical Cannabis' Active Pharmaceutical Ingredients' Physical Properties and Compositions

Medical cannabis products contain dozens of active pharmaceutical ingredients (APIs) derived from the cannabis plant. However, their actual compositions and relative doses significantly change according to the production methods. Product compositions are strongly dependent on processing step conditions and on components' evaporation during those steps. Review of the documentation presented to caregivers and to patients show erroneous data or misinterpretation of data related to the evaporation, for example, cannabinoids' boiling points, as well as confusions between terms, such as boiling, vaporization, and evaporation. Clarifying these aspects is essential for caregivers, for researchers, and for developers of manufacturing processes. Original and literature data were analyzed, comparing composition changes during various processing steps and correlating the extent of change to components' vapor pressures at the corresponding temperature. Evaporation-related composition changes start at temperatures as low as those of drying and curing and become extensive during decarboxylation. The relative rate of components' evaporation is determined by their relative vapor pressure and monoterpenes are lost first. On vaping, terpenes are inhaled before cannabinoids do. Commercial medical cannabis products are deficient in terpenes, mainly monoterpenes, compared with the cannabis plants used to produce them. Terms, such as "whole plant" and "full spectrum," are misleading since no product actually reflects the original cannabis plant composition. There are important implications for medical cannabis manufacturing and for the ability to make the most out of the terpene API contribution. Medical cannabis products' composition and product delivery are controlled by the relative vapor pressure of the various APIs. Quantitative data provided in this study can be used for improvement to reach better accuracy, reproducibility, and preferred medical cannabis compositions.

Analysis of the Aerosol Generated from Tetrahydrocannabinol, Vitamin E Acetate, and Their Mixtures

E-cigarette, or vaping, product use-associated lung injury (EVALI) outbreak was linked to vitamin E acetate (VEA) used as a solvent for tetrahydrocannabinol (THC). Several studies were conducted to assess the products of VEA (and THC/VEA mixtures) thermal degradation as a result of vaporizing/aerosolizing from a traditional type (coil-cotton wick) and ceramic type coil vape pens. The particle size distribution (PSD) of VEA aerosol and the temperature VEA and THC/VEA mixtures are heated to were also measured for a few types of traditional and ceramic vape pens. The current study assessed the PSD of the aerosol generated from THC, VEA, and a number of THC/VEA mixtures using a dab-type vape pen under two different temperature settings and two puffing flow rates. Thermal degradation of THC, VEA, and THC/VEA mixtures were also assessed, and coil temperature was measured. Results showed the dependence of the PSD upon the chemical content of the aerosolized mixture as well as upon the puffing flow rate. Minimal thermal degradation was observed. Flaws in the vape pen's design, which most likely affected results, were detected. The suitability of VEA, THC, and THC/VEA mixtures with certain types of vape pens was discussed.

Thirdhand smoke from tobacco, e-cigarettes, cannabis, methamphetamine and cocaine: Partitioning, reactive fate, and human exposure in indoor environments

A source of chemical exposure to humans, thirdhand smoke (THS) refers to the contamination that persists indoors following the cessation of a smoking event. The composition of thirdhand smoke depends on the type of substance from which it originates. Although past studies have investigated the effects of tobacco THS on indoor air quality and human health, few have focused on the chemical composition and health impacts of other sources and components of THS. Here we review the state of knowledge of the composition and partitioning behavior of various types of indoor THS, with a focus on THS from tobacco, e-cigarettes, cannabis, and illicit substances (methamphetamine and cocaine). The discussion is supplemented by estimates of human exposure to THS components made with a chemical fate and exposure model. The modeling results show that while very volatile THS compounds (i.e., aromatics) are likely to be taken up by inhalation, highly water-soluble compounds tended to be dermally absorbed. Conversely, minimally volatile THS compounds with low solubility are predicted to be ingested through hand-to-mouth and object-to-mouth contact.

Emerging trends in point-of-care sensors for illicit drugs analysis

Consumption of illicit narcotic drugs and fatal or criminal activities under their influence has become an utmost concern worldwide. These drugs influence an individual's feelings, perceptions, and emotions by altering the state of consciousness and thus can result in serious safety breaches at critical workplaces. Point-of-care drug-testing devices have become the need-of-the-hour for many sections such as the law enforcement agencies, the workplaces, etc. for safety and security. This review focuses on the recent progress on various electrochemical and optical nanosensors developed for the analysis of the most common illicit drugs (or their metabolites) such as tetrahydrocannabinol (THC), cocaine (COC), opioids (OPs), amphetamines & methamphetamine, and benzodiazepine (BZDs). The paper also highlights the sensitivity and selectivity of various sensing modalities along with evolving parameters such as real-time monitoring and measurement via a smart user interface. An overall outlook of recent technological advances in point of care (POC) devices and guided insights and directions for future research is presented.

Preservation of vapor samples on adsorbent alumina capillaries and implications for field sampling

Dynamic vapor microextraction (DVME) is a vapor preconcentration method that employs a capillary trap coated with an adsorbent, followed by solvent elution to recover the sample. DVME has been developed for applications in the laboratory, including highly precise vapor pressure measurements, and in the field. When vapor collection is conducted outside the laboratory, samples must almost always undergo some interval of storage representing the time between collection and analysis. This interval may be hours, days, or longer, depending on the situation. Regardless, in all situations there must be confidence that the integrity of the samples is maintained until processing and analysis. In this paper, we present results of two studies that tested the stability of a 50% weathered gasoline headspace sample on alumina PLOT (porous layer open tubular) capillaries stored at room temperature for periods from 24 h up to 20 wk. We used principal component analysis (PCA) to reduce the dimensionality of the chromatographic and mass spectral data and elucidate trends in stability with respect to the complex sample's range of hydrocarbon classes and molecular weights. Both analyses identified changes over storage periods of six weeks or more. The hydrocarbon class analysis, which used selected ion monitoring (SIM) data as input, proved more sensitive to changes over shorter storage periods. Sample integrity was preserved for at least 24 h, but losses, especially of high-volatility compounds, occurred by 168 h (7 d). Near total loss of sample occurred by 20 wk. These findings, which are specific to the sample, adsorbent, and storage conditions, will guide choices in experimental and instrumental design to ensure that data from future field studies is reliable.

Cannabis Vaping: Existing and Emerging Modalities, Chemistry, and Pulmonary Toxicology

The outbreak of e-cigarette or vaping product use-associated lung injury (EVALI) has been cause for concern to the medical community, particularly given that this novel illness has coincided with the COVID-19 pandemic, another cause of severe pulmonary illness. Though cannabis e-cigarettes tainted with vitamin E acetate were primarily associated with EVALI, acute lung injuries stemming from cannabis inhalation were reported in the literature prior to 2019, and it has been suggested that cannabis components or additives other than vitamin E acetate may be responsible. Despite these concerning issues, novel cannabis vaporizer ingredients continue to arise, such as Δ⁸-tetrahydrocannabinol, Δ¹⁰-tetrahydrocannabinol, hexahydrocannabinol, and cannabichromene. In order to address cannabis e-cigarette safety and vaping in an effective manner, we provide a comprehensive knowledge of the latest products, delivery modes, and ingredients. This perspective highlights the types of cannabis vaping modalities common to the United States cannabis market, with special attention to cartridge-type cannabis e-cigarette toxicology and their involvement in the EVALI outbreak, in particular, acute lung injurious responses. Novel ingredient chemistry, origins, and legal statuses are reviewed, as well as the toxicology of known cannabis e-cigarette aerosol components.

The influence of terpenes on the release of volatile organic compounds and active ingredients to cannabis vaping aerosols

Cannabinoid and VOC emissions from vaping cannabis concentrates vary depending on terpene content, power level and consumption method.

Rapid Vapor-Collection Method for Vapor Pressure Measurements of Low-Volatility Compounds

Dynamic vapor microextraction (DVME) is a new method that enables rapid vapor pressure measurements on large molecules with state-of-the-art measurement uncertainty for vapor pressures near 1 Pa. Four key features of DVME that allow for the rapid collection of vapor samples under thermodynamic conditions are (1) the use of a miniature vapor-equilibration vessel (the "saturator") to minimize the temperature gradients and internal volume, (2) the use of a capillary vapor trap to minimize the internal volume, (3) the use of helium carrier gas to minimize nonideal mixture behavior, and (4) the direct measurement of pressure inside the saturator to accurately account for overpressure caused by viscous flow. The performance of DVME was validated with vapor pressure measurements of n-eicosane (C₂₀H₄₂) at temperatures from 344 to 374 K. A thorough uncertainty analysis indicated a relative standard uncertainty of 2.03-2.82% for measurements in this temperature range. The measurements were compared to a reference correlation for the vapor pressures of n-alkanes; the deviation of the measurements from the correlation was ≤2.85%. The enthalpy of vaporization of n-eicosane at 359.0 K was calculated to be Δ_vapH = 91.27 ± 0.28 kJ/mol compared to Δ_vapH(corr) = 91.44 kJ/mol for the reference correlation. Total measurement periods as short as 15 min (3 min of thermal equilibration plus 12 min of carrier gas flow) were shown to be sufficient for high-quality vapor pressure measurements at 364 K.

Heterogeneous Ozonolysis of Tetrahydrocannabinol: Implications for Thirdhand Cannabis Smoke

Thirdhand smoke (THS) deposits to surfaces following smoking events and is a source of chemical exposure to humans. However, the evolution of THS in indoor environments is not well understood. Cannabis THS is a chemically distinct and prevalent form of THS, which has not been studied. The heterogeneous reaction of Δ⁹-tetrahydrocannabinol (THC), a major component of cannabis smoke, with ozone was examined as a pure compound and within cannabis smoke. Oxidative decay via ozonolysis and product formation were monitored by liquid chromatography-tandem mass spectrometry. Epoxide, dicarbonyl, and secondary ozonide THC reaction products were detected from both pure THC and cannabis experiments, with the product ratios dependent on relative humidity. The observed reaction kinetics for loss of THC on glass and cotton surfaces are consistent with a relatively short loss lifetime, which will be strongly dependent on the film thickness, ozone mixing ratio, and ozone reactivity of the surface substrate. The low volatility of THC and its oxidation products suggest that their contributions to thirdhand cannabis smoke will be less significant than the role that nicotine plays in thirdhand tobacco smoke.

Topical review on monitoring tetrahydrocannabinol in breath

Legalization of cannabis for recreational use has compelled governments to seek new tools to accurately monitor Δ9-tetrahydrocannabinol (Δ9-THC) and understand its effect on impairment. Various methods have been employed to measure Δ9-THC, and its respective metabolites, in different biological matrices. Recently, breath analysis has gained interest as a non-invasive method for the detection of chemicals that are either produced as part of biological processes or are absorbed from the environment. Existing breath analyzers function by analyzing previously collected samples or by direct real-time analysis. Portable hand-held devices are of particular interest for law enforcement and personal use. This paper reviews and compares both commercially available and prototype devices that proclaim Δ9-THC detection in exhaled breath using methods such as Field Asymmetric Ion Mobility Spectrometry, Semiconductor-Enriched Single-Walled Carbon Nanotube chemiresistors, Liquid Chromatography Tandem-mass Spectrometry, microfluidic-based artificial olfaction, and optical-based gas sensing.

Predicting Sorbent-Air Partition Coefficients for Terpenoids at Multiple Temperatures

Partition coefficients describe the relative concentration of a chemical equilibrated between two phases. In the design of air samplers, the sorbent-air partition coefficient is a critical parameter, as is the ability to extrapolate or predict partitioning at a variety of temperatures. Our specific interest is the partitioning of plant-derived terpenes (hydrocarbons formed from isoprene building blocks) and terpenoids (with oxygen-containing functional groups) in polydimethylsiloxane (PDMS) sorbents. To predict K P D M S / A I R as a function of temperature for compounds containing carbon, hydrogen, and oxygen, we developed a group contribution model that explicitly incorporates the van't Hoff equation. For the 360 training compounds, predicted K P D M S / A I R values strongly correlate (R² > 0.987) with K P D M S / A I R values measured at temperatures from 60 °C to 200 °C. To validate the model with available literature data, we compared predictions for 50 additional C₁₀ compounds, including 6 terpenes and 22 terpenoids, with K P D M S / A I R values measured at 100 °C and determined an average relative error of 3.1 %. We also compared predictions with K P D M S / A I R values measured at 25 °C. The modeling approach developed here is advantageous for properties with limited experimental values at a single temperature.

Measuring Within-Individual Cannabis Reduction in Clinical Trials: A Review of the Methodological Challenges

Purpose

Cannabis abstinence traditionally is the primary outcome in cannabis use disorder (CUD) treatment trials. Due to the changing legality of cannabis, patient goals, and preliminary evidence that suggests individuals who reduce their cannabis use may show functional improvements, cannabis reduction is a desirable alternative outcome in CUD trials. We review challenges in measuring cannabis reduction and the evidence to support various definitions of reduction.

Findings

Reduction in number of cannabis use days was associated with improvements in functioning across several studies. Reductions in quantity of cannabis used was inconsistently associated with improvements in functioning, though definitions of quantity varied across studies. Different biomarkers may be used depending on the reduction outcome.

Conclusions

Biologically-confirmed reductions in frequency of cannabis use days may represent a viable endpoint in clinical trials for cannabis use disorder. Additional research is needed to better quantify reduction in cannabis amounts.

Can Metal-Organic Frameworks Be Used for Cannabis Breathalyzers?

Δ⁹-Tetrahydrocannabinol (THC) is the principal psychoactive component of cannabis, and there is an urgent need to build low-cost and portable devices that can detect its presence from breath. Similarly to alcohol detectors, these tools can be used by law enforcement to determine driver intoxication and enforce safer and more regulated use of cannabis. In this work, we propose to use a class of microporous crystals, metal-organic frameworks (MOFs), to selectively adsorb THC that can be later detected using optical, electrochemical, or fluorescence-based sensing methods. We computationally screened more than 5000 MOFs, highlighting the materials that have the largest affinity with THC, as well as the highest selectivity against water, showing that it is thermodynamically feasible for MOFs to adsorb THC from humid breath. We propose and compare different models for THC and different computational protocols to rank the promising materials, also presenting a novel approach to assess the permeability of a porous framework to nonspherical molecules. We identified three adsorption motifs in MOFs with high affinity to THC, which we refer to as "narrow channels", "thick walls", and "parking spots". Therefore, we expect our protocols and our findings to be generalizable for different classes of microporous materials and also for investigating the adsorption properties of other large molecules that, like THC, have a nonspherical shape.

Toxicant Formation in Dabbing: The Terpene Story

Inhalable, noncombustible cannabis products are playing a central role in the expansion of the medical and recreational use of cannabis. In particular, the practice of "dabbing" with butane hash oil has emerged with great popularity in states that have legalized cannabis. Despite their growing popularity, the degradation product profiles of these new products have not been extensively investigated. The study herein focuses on the chemistry of myrcene and other common terpenes found in cannabis extracts. Methacrolein, benzene, and several other products of concern to human health were formed under the conditions that simulated real-world dabbing. The terpene degradation products observed are consistent with those reported in the atmospheric chemistry literature.