quantification of nicotine and major solvents in retail electronic cigarette fluids and vaped aerosols

Introduction:
This text is a summary of a scientific study that examines the composition and emission factors of electronic cigarette (e-cigarette) refill solutions. The study aims to assess the levels of nicotine, propylene glycol (PG), and vegetable glycerol (VG) in both e-liquids and vaped aerosols, and to validate the reliability of an analytical method for quantifying these substances in both liquid and aerosol samples.

Key points:

* The study used a third-generation e-cigarette device and 16 popular brands of e-liquids, purchased from online and offline retail suppliers in South Korea.
* Three 100 mg aliquots of each e-liquid were diluted in methanol containing an internal standard, and 1 μL of the diluted sample was analyzed by gas chromatography with a flame ionization detector (GC-FID).
* Vaped aerosol samples were collected on Cambridge filter pads (CFP) and extracted in methanol. The quantification of all targets was carried out based on the mass change tracking (MCT) approach.
* The measured concentrations of nicotine, PG, and VG in the 16 e-liquids varied in the ranges of 6.76 to 16.3 mgg-1, 356 to 657 mg g-1, and 286 to 548 mg g-1, respectively.
* The measured concentrations of nicotine and PG in vaped aerosol samples from all 16 e-liquids were generally lower than those from e-liquid samples, while they were slightly higher for VG.
* The emission factors of nicotine, PG, and VG released via e-cigarette vaping are important parameters to assess their impact on air quality and human health. The emission factors for nicotine were lower (39.6 μg puff-1) than those of a Kentucky 2R4F reference cigarette (75 μg puff-1).
* The study found that the percentage composition of PG + VG was in a range of 75.4 to 92.1% (w/w), whereas Nic was in the range from 0.57 to 1.47% (w/w) in vaped aerosol samples.

Main message:
This study provides important information on the composition and emission factors of e-cigarette refill solutions, which can be useful for regulators to assess the health risks associated with e-cigarette use. The study found that the measured nicotine concentrations in e-liquids differed from the declared label concentrations, and that the emission factors of nicotine were lower than those of a Kentucky 2R4F reference cigarette. The study also highlights the need for further research to build an accurate database of e-liquid compositions and to assess the effects of other parameters, such as coil and clearomizer performance, on e-cigarette emissions.

Dai, Jun, Ki-hyun Kim, Jan E. Szulejko, Sang-hee Jo, Kyenghee Kwon, and Dal Woong Choi. “quantification of Nicotine and Major Solvents in Retail Electronic Cigarette Fluids and Vaped aerosols.” Microchemical Journal 140 (July 2018): 262–68. https://doi.org/10.1016/j.microc.2018.04.028.