An inter-machine comparison of tobacco smoke particle deposition in vitro from six independent smoke exposure systems

Abstract

There are several whole smoke exposure systems used to assess the biological and toxicological impact of tobacco smoke in vitro. One such system is the Vitrocell® VC 10 Smoking Robot and exposure module. Using quartz crystal microbalances (QCMs) installed into the module, we were able to assess tobacco smoke particle deposition in real-time. We compared regional deposition across the module positions and doses delivered by six VC 10s in four independent laboratories: two in the UK, one in Germany and one in China. Gauge R&r analysis was applied to the total data package from the six VC 10s. As a percentage of the total, reproducibility (between all six VC 10s) and repeatability (error within an individual VC 10) accounted for 0.3% and 7.4% respectively. Thus Gauge R&r was 7.7%, less than 10% overall and considered statistically fit for purpose. The dose-responses obtained from the six machines across the four different locations demonstrated excellent agreement. There were little to no positional differences across the module at all airflows as determined by ANOVA (except for one machine and at three airflows only). These results support the on-going characterisation of the VC 10 exposure system and suitability for tobacco smoke exposure in vitro.

Application of dosimetry tools for the assessment of e-cigarette aerosol and cigarette smoke generated on two different in vitro exposure systems

“…The ratio difference in deposited nicotine concentration between cigarette and e-cigarette on the VC 10 ranged 7.65–10.03 at the first three dilutions but decreased to 2.52 at 1 l/min. These ratio comparisons show agreement at all dilutions on the RM20S; the VC 10 shows parity but there are greater product differences at higher air flow rates and we have previously reported variances in dose delivery from flow rates around 0.5 l/min [1]. …”

The mutagenic assessment of mainstream cigarette smoke using the Ames assay: A multi-strain approach

“…A quartz crystal microbalance (QCM) (Vitrocell ® Systems, Waldkirch, Germany) was included in situ of exposure at position 4 within the Ames module, distal to the smoke inlet, as previously demonstrated [38][39][40]. QCMs provide a gravimetric measure of deposited mass, providing a valuable quality control (QC) measure of smoke exposure within and between runs, and allows data to be presented as a function of deposited mass (g/cm 2 ).…”

Cigarette Mainstream Smoke: The Evolution of Methods and Devices for Generation, Exposure and Collection

“…This way, different smoke generation and dilution systems can be characterized and compared directly regarding their performance and potential to supply suitable atmospheres for exposure studies. After three earlier studies (475,476,492) had convincingly demonstrated the value of quartz crystal microbalances (QCMs) for the quantitative assessment of cigarette smoke particle deposition, ADAMSON et al (493) used QCM technology for a comparative evaluation of Vitrocell ® smoke generation and exposure systems. The direct gravimetric measurement of precipitated mass per surface area in real time and in situ offered considerable advantages over traditional methods, such as measurement of fluorescence or differential mobility spectrometry backed by specific air flow rates.…”

“…When different concentrations of smoke were examined a linear correlation between optical density and dilution was shown. In the very same experiment, quartz crystal microbalances (QCMs) were installed into each of the seven pipe connectors between the smoke dilution elements and the base module -and not placed in any of the wells as done by ADAMSON et al (475,476,492,493) in a number of earlier studies. Particle deposition was monitored online and the final mass determined at the end of the smoking run.…”