Use of Classical Adsorption Theory to Understand the Dynamic Filtration of Volatile Toxicants in Cigarette Smoke by Active Carbons

Abstract

The ability of two very different active carbons, a polymer-derived carbon (with ultramicropores and supermicropores, and a large volume of "transport" pores) and a coconut shell-derived carbon (predominantly ultramicroporous), to reduce the levels of volatile toxicants in cigarette smoke has been measured and compared. The polymer-derived carbon was found to be approximately twice as effective in removing the majority of measured smoke vapour-phase toxicants compared to the coconut shell-derived carbon in three different cigarette formats and with two different smoking regimes. Singlecomponent dynamic breakthrough experiments were conducted with benzene, acrylonitrile and 2-butanone at 298 K for beds of each carbon under dry (0% RH) and wet (60% RH) conditions. Longer breakthrough times were found with the polymer-derived carbon, and breakthrough times recorded under wet conditions were found to be up to 20% shorter than those obtained under dry conditions. Correlations between micropore volume, dynamic adsorption volume and filter bed breakthrough time have been demonstrated.

Reference change values to assess changes in concentrations of biomarkers of exposure in individuals participating in a cigarette-switching study

“…Two groups of subjects continued to smoke the 1 mg and 6 mg commercial cigarettes for the remaining 4 weeks of the study (commercial control groups CC1 and CC6, respectively), whereas the others were switched to an RTP cigarette with the same ISO tar yield as their usual brand (one 6 mg ISO tar yield RTP, TSS6, or one of two 1 mg ISO tar yield RTPs: TSS1, which contained tobacco-substitute sheet in the blend and high activity carbon and amine-functionalised resin in the filter, or BT1, which contained water and enzyme-treated Virginia tobacco in the tobacco blend and the same filter as TSS1). These products are described in greater detail elsewhere [15,[19][20][21][22]. Urine samples were collected and cigarette consumption recorded in two further periods of clinical confinement (Supplemental Data, Figure 1, which accompanies the article at http://www.degruyter.com/view/j/ cclm.2014.52.issue-3/issue-files/cclm.2014.52.issue-3.xml).…”

Pressure and Gas Flow Distribution Inside the Filter of a Non-Filter Ventilated Lit Cigarette During Puffing

“…As the smoke passes through the filter, different degrees of chemical affinity towards the plasticiser and/or filter material by different classes of compounds cause variation in their retention. To this end, incorporating other adsorptive materials such as granular charcoal or amine-functionalised resin beads provides further opportunities to chemically interact with volatile and semi-volatile organic compounds such as aldehydes and hydrogen cyanide (11,12). Modern commercial cigarettes have ventilation holes through the wrapping paper surrounding the CA filter in order to dilute the mainstream smoke under puffing (1,13,14).…”

Thermal desorption comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry for vapour phase mainstream tobacco smoke analysis

“…A and B cigarettes had a circumference of 24.6 mm and were made up of a 56-mm long tobacco rod containing a US style tobacco blend (tobacco rod density of 235 mg cm −3 at a moisture content of 13.5%). The carbon used in this study was a high activity, polymerbased material whose production, composition and performance have been described in detail previously [24].…”

“…The detailed description about these two cigarette types and their PP chemical compositions have been reported previously [1], but limited data are currently available regarding the real chemical impact of such filter on the VP composition [24]. Samples were pre-processed by mean of background correction and blob detection.…”