A solvent-free squeezing method for extraction of collected mass from aerosols of electronic cigarettes and heated tobacco products

• Published in: Journal of Chromatography A 2024-07, Vol.1727, p.465009, Article 465009
• Main Authors: Ito, Hiroshi, Shigeto, Atsushi, Hashizume, Tsuneo
• Format: Article
• Language: English
• Subjects: Concentrated aerosol collected mass extract; Electronic cigarettes; Extraction efficiency; Heated tobacco products; Solvent-free squeezing method
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2024.465009

•Developed solvent-free method for e-cigarette and heated tobacco product aerosols.•Concentrated aerosol collected mass extracted by squeezing from Cambridge filter pads.•Extraction method suitable for various constituents in e-cigarette aerosols.•Method inadequate for lipophilic constituents from heated tobacco product aerosols. Previous in vitro toxicological assessments have demonstrated that almost no mutagenic and genotoxic activities in electronic cigarette (e-cigarette) and heated tobacco product (HTP) aerosols were detected even at the maximum recommended concentration. To accurately compare the toxicity levels between cigarette smoke and e-cigarette or HTP aerosols, higher exposure concentrations increasing the possibility to detect toxicity in in vitro tests are necessary, while avoiding solvent-induced toxicity. This study aimed to develop a solvent-free extraction method to obtain concentrated aerosol extracts for improved toxicological evaluation. Our novel approach involved squeezing several Cambridge filter pads, which collected aerosol constituents, in closed containers to achieve solvent-free extraction with comparable efficiency to the conventional method using organic solvents. The optimized squeezing method yielded extracts with concentrations approximately 10 times higher than those obtained in conventional extraction methods. Yield comparison of various constituents, such as flavoring compounds, in e-cigarette aerosol extracts revealed similar extraction efficiencies between the squeezing and conventional methods. However, the extraction efficiency for constituents with high log Pow values, predominantly found in HTP aerosol extracts, was unacceptably low using the squeezing method. In addition, solvent-free centrifuging, another type of extraction method, exhibited unsatisfactory results for even e-cigarette aerosols compared with the conventional method. Our findings suggest that the solvent-free squeezing method is suitable for extracting aerosol collected mass from e-cigarette aerosol but not from HTP aerosol. We anticipate that the solvent-free squeezing method will contribute to a deeper understanding of toxicological differences between e-cigarettes and conventional combustible cigarettes.