Analysis of illicit drugs in purchased and seized electronic cigarette liquids from the United Kingdom 2014-2021 (2023)

Increasing popularity and known shortfalls in the regulation of electronic cigarettes (ECs) emphasises the urgent need for closer content monitoring and for comprehensible information on their possible health effects. This study investigated components of EC liquids in samples submitted from 2014 to 2021 and discussed the trends driven by legislation changes. Samples originating from prisoners, teenagers and ‘test purchases’ of commercially available ECs were analysed by gas chromatography-mass spectrometry (GC-MS). For those containing delta-9-tetrahydrocannabinol (THC) and/or cannabidiol (CBD), the content of these components was quantified by liquid chromatography with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) to show variation of these compounds in EC liquids; 112 EC liquids were included in this study. Nicotine was detected in 87 (78%) of the EC liquids analysed. Twenty-two, including samples from before and after introduction of the UK Psychoactive Substances Act (2016), contained one or more synthetic cannabinoid receptor agonist (SCRA). THC was detected in only 11 samples, whereas a single sample was found to contain CBD only. Six samples contained a mixture of THC and CBD. In all cases where information was available, the THC/CBD content was less than that stated on the product label. The data collected showed great variation in EC liquid content. Therefore, it is important that users are educated regarding risks associated with EC use. Additionally, substances now controlled under both the UK Misuse of Drugs Act and Psychoactive Substances Act were present. These substances each carry a potential risk to health, which is possibly exacerbated if multiple compounds are inhaled concomitantly.