EVALI Vaping Liquids Part 2: Mass Spectrometric Identification of Diluents and Additives.

The vaping liquid additive vitamin E acetate (VEA) was strongly linked to the 2019 United States nationwide outbreak of pulmonary lung illness (EVALI) associated with e-cigarettes or vaping liquids. Our laboratory received over 1,000 vaping liquid products for identification of the vaping liquid additives, including hundreds of vaping products from EVALI patients. In this work, we present results obtained for the GC-MS identification of numerous vaping liquid additives in a large subset of ca. 300 Cannabis vaping liquids, including vitamin E acetate, medium chain triglycerides oil (MCT oil), polyethylene glycols, squalane, triethyl citrate, dipropylene glycol dibenzoate (DPG dibenzoate), pine rosin acids, pine rosin methyl esters, and sucrose acetate isobutyrate (SAIB). Confirmation of DPG dibenzoate and SAIB using LC-HRMS is also presented. GC-MS analysis for additives identified as the parent compounds was conducted after separation on a commercial 5% phenyl phase. GC-MS analysis for additives identified as the trimethylsilyl derivatives was conducted after separation on a commercial 35% silphenylene phase. LC-HRMS analysis was conducted using gradient elution with either C18 or phenyl-hexyl phases and determination of exact masses for the target compounds. In addition to providing rapid methods for the identification of vaping liquid additives, this work highlights the variety of Cannabis vaping liquid additives in current use.

EVALI Vaping Liquids Part 1: GC-MS Cannabinoids Profiles and Identification of Unnatural THC Isomers.

Tetrahydrocannabinol (THC)-containing products played a major role in the 2019 US nationwide outbreak of pulmonary lung illness associated with e-cigarettes or vaping liquids (EVALI). Due to the severity of the illness which resulted in 68 deaths, a comprehensive identification of the components in the vaping liquids was required. Our laboratory received over 1000 vaping liquid products for analysis including hundreds of vaping products from EVALI patients. In this work, we present the results for the GC-MS identification of the cannabinoids from a large subset of ca. 300 Cannabis-based vaping liquids, with emphasis on the identification of a series of unnatural THC isomers. GC-MS analysis was conducted using a validated, published method in which the cannabinoids were identified as the trimethylsilyl derivatives after separation on a commercial 35% silphenylene phase. Δ9- Tetrahydrocannabinol is the naturally occurring THC isomer found in the Cannabis plant, and was found in the majority of the vaping liquids. However, we also identified the presence of one or more additional THC isomers in many of the vaping liquids including Δ8-tetrahydrocannabinol, Δ6a,10a-tetrahydrocannabinol, Δ10-tetrahydrocannabinol, and exo-tetrahydrocannabinol. Significant or major amounts of unnatural THC isomers were found in over 10% of the THC vaping liquids, with lesser amounts found in another 60% of the vaping liquids. Exposure of the Cannabis source materials (such as marijuana concentrates or converted hemp materials) to chemical and thermal treatments during manufacturing, is proposed as the primary cause for the THC isomerizations.

Commercial cannabis consumer products part 2: HPLC-DAD quantitative analysis of cannabis cannabinoids.

Quantitative analysis for the cannabis cannabinoids such as cannabidiol and Δ9-tetrahydrocannabinol in commercial products is necessary for evaluating label information, and assessing dosages and exposures when the products are consumed. Herein is presented a broadly applicable HPLC-DAD method for the determination of cannabis cannabinoids in commercial consumer products and traditional plant-related substances. The current method provides chromatographic resolution of 11 cannabinoids using a commercial, mixed C18-aromatic functionality stationary phase. The method uses 95% or pure ethanol for extraction, and certain modifications which address specific matrix types are detailed herein. Extensive method validation including precision and accuracy was conducted for five cannabinoids of primary interest (CBD, Δ9-THC, CBDA, THCA, and CBN). UV detection provided excellent sensitivity with limits of quantitation (LOQs) of 10µg/g across cannabinoids. The method was applied to about 60 commercial products representing diverse product types and a broad range of cannabinoids amounts (0.01-350mg/g).

Commercial cannabis consumer products part 1: GC-MS qualitative analysis of cannabis cannabinoids.

The recent surge in the sale of cannabis-based consumer products in the US includes foods, candies, beverages, topicals, vapes/eliquids, oral supplements in various forms, recreational marijuana plants, and plant extracts or preparations. The wide variety of product and sample types has resulted in a host of new matrix interferences when conducting qualitative testing for the cannabis cannabinoids such as cannabidiol and d9-tetrahydrocannabinol. A qualitative GC-MS method is presented in this work, which uses a commercial 35% silphenylene phase to provide chromatographic resolution for 11 target cannabinoids as their trimethylsilyl derivatives (CBD, CBDA, d9THC, THCA, CBN, d8THC, CBG, CBGA, CBDV, THCV, and CBC). The method uses variants of ethanol- and acetonitrile-based extractants to successfully minimize or eliminate several types of interferents, and also provides protocols to address specific interferents such as glycerin and lactose. Method validation included spike/recovery for five cannabinoids of primary interest (spiking level 50µg/g) from a series of edible oils, foods, beverages, candies, topicals, oral OTC pharmaceuticals, glycerin, and propylene glycol. The minimum detectable concentration was established as 1.0µg/g. The method was applied to about sixty diverse commercial products, as well as to recreational marijuana plants, plant preparations, hempseed oils, and dronabinol capsules.

Rapid selective screening and determination of ephedrine alkaloids using GC-MS footnote mark.

Ephedra (ma huang) has been widely used as an herb or herbal extract in both traditional Chinese medicine and Western world dietary supplements. The effects of Ephedra have been attributed to a series of six ephedrine alkaloids including ephedrine and pseudoephedrine. A GC-MS method for the ephedrine alkaloids is described which couples ammoniacal chloroform as the extraction solvent with a two-stage derivatisation scheme. This scheme produces the O-trimethylsilyl, N-trifluoracetyl derivatives (O-TMS, N-TFA) for the primary and secondary amine alkaloids, and the O-TMS derivatives for the tertiary amine alkaloids. Relatively clean extracts are obtained from complex matrices, and the six ephedrine alkaloids are effectively separated and identified. This approach was also evaluated for quantitative analysis, and was shown to provide quantitative results for ephedrine and pseudoephedrine, and good estimates for the four minor alkaloids. Figures of merit are presented for linearity, detection limits, precision and accuracy. We have applied this approach to the rapid screening and profiling of the ephedrine alkaloids in whole Ephedra plants, liquid plant extracts, dried powder plant extracts and a variety of Ephedra-containing dietary supplements.