Release of toxic ammonia and volatile organic compounds by heated cannabis and their relation to tetrahydrocannabinol content

Abstract

Studies have been carried out of the compounds generated from heated "street" cannabis in the commercial device known as the "Volcano" using the selected ion flow tube mass spectrometry (SIFT-MS) analytical method. Such vaporising devices are preferred for the delivery of the cannabis active ingredients for pain relief and therapeutic purposes since they remove from the smoke the harmful high molecular weight compounds such as tars and polycyclic aromatic hydrocarbons. Whilst it is known that smoking cannabis is associated with adverse health effects, little is known about risks of its inhalation of volatile compounds from vaporizers. In the present study, the concentrations of the volatile lower molecular weight compounds ammonia, methanol, acetic acid, methyl acetate, monoterpenes and sesquiterpenes present in the trapped air/vapour volume of the "Volcano" have been determined directly by SIFT-MS obviating sample collection/pre-concentration and delayed off-line analysis as used by most other analytical techniques. The concentrations of these compounds are compared to the tetrahydrocannabinol (THC; expected to be largely D-9-THC) content of the cannabis plant material as assayed using standard extraction/derivatisation/GC-MS analysis. The observed high concentrations of ammonia were strongly correlated with the THC which is largely contained in the buds of the cannabis plant, whereas the identified volatile organic compounds were predominantly released by the leaves.Whilst the "Volcano" device removes some toxic compounds from the smoke and reduces their inhalation by its user, it likely leads to enhanced ingestion of toxic ammonia known to result in neurobehavioral impairment.

Emissions from Heated Terpenoids Present in Vaporizable Cannabis Concentrates

“…Particularly relevant are terpenoids, lignans, and flavonoids, 13−16 which may form harmful byproducts when heated. Monoterpenes, sesquiterpenes, sesquiterpenoid alcohols, and triterpenes are of particular concern because they are present in large amounts 17 and are likely to generate, upon heating, ultrafine particles (UFPs) and low-molecular-weight oxidized byproducts that irritate the respiratory system. Thermal degradation of terpenoids results in byproducts from dehydrogenation, epoxidation, double-bond cleavage, allylic oxidations, and rearrangements.…”

“…Particularly relevant are terpenoids, lignans, and flavonoids, − which may form harmful byproducts when heated. Monoterpenes, sesquiterpenes, sesquiterpenoid alcohols, and triterpenes are of particular concern because they are present in large amounts and are likely to generate, upon heating, ultrafine particles (UFPs) and low-molecular-weight oxidized byproducts that irritate the respiratory system.…”

Microwave Extraction vs. Other Techniques for Industrial Scale Cannabis Extraction

“…To be therapeutically active, these acidic cannabinoids must be converted to their neutral forms by a decarboxylation reaction. Decarboxylation is instant when cannabis is combusted during smoking [12]. All other consumption forms containing cannabis extracts must however involve a decarboxylation step to produce the active neutral forms.…”

Microwave-Assisted Industrial Scale Cannabis Extraction

“…Historical delivery methods of cannabis have involved smoking, i.e., combusting the dried cannabis plant material [13]. Smoking results, however, in adverse effects on the respiratory system via the production of potentially toxic substances [14]. Alternative delivery methods such as oral administration under edible or spray forms and transdermal delivery of topical forms all require some method of extraction of the cannabinoids from the raw biomass [15,16].…”