Volume 9 (1978): Issue 4 (July 1978)

A commercially available light emitting diode/phototransistor array was investigated for detection and analysis of tobacco smoke in the Walton Horizontal Smoking Machine (WHSM) animal inhalation exposure system. The diode element of the device emits light into the smoke aerosol, and light back-scattered by the smoke particles is detected by the phototransistor element. The sensor provides a continuous, nearly instantaneous graphicaI visualization of smoke particulates in the immediate vicinity of the array. Experimental studies showed that sensor readout is Iinearly related to smoke particulate concentration of the smoke and is independent of the composition of the smoke. Smoke particle agglomeration associated with aging of smoke causes observable but minor changes in sensor response.

A graphical method is presented showing the inter-relationship of the air flow resistance of the cigarette, itself, and that of the ventilation in the filter tips in determining the dilution produced by that ventilation. The method was checked by direct, steady-state measurements of dilution of unlit cigarettes to which a resistance was added simulating the resistance of the burning coal.

The importance of determining not only the nominal permeability of papers, but also the nature of the flow resistance was confirmed, for cigarette wrapper and for papers used in constructing ventilated filters. For perforated papers, for which the flow is not proportional to pressure drop, it was shown that logarithmic plotting and the use of the form V = k (D P)ⁿ is satisfactory and convenient. In applying this principle to ventilated filters it was found that limited, but significant, lateral flow occurs between the tipping and porous plug wrap papers, although the flow does not extend over the entire unglued area. With the use of small perforations and extremely porous plug wrap paper, the resistance of the plug wrap paper plays a very minor part in controlling dilution flow.

The diffusion of CO and CO₂ through the wrapper of cigarettes was studied by direct measurement under steady-state conditions, simulating the conditions which obtain during puffing. Cigarettes made with porous paper, with perforated paper and with ventilated filters were studied. The diffusion of CO and CO₂ from cigarettes was found to be strongly influenced by the mode of cigarette ventilation. The greatest effect of diffusion on CO delivery was found for cigarettes where ventilation was achieved by ventilating the filter. The influence on diffusion of the type and amount of burn chemical applied to the paper is described as well as changing the average pressure drop across the cigarette. It was found that normal levels of burn chemicals added to the paper will only slightly decrease the fraction of CO diffusing through the wrapper.

Cigarette smoke condensate (CSC) processed with acetone was found to contain 2,2,6-trimethyl-4-piperidone and the cis and trans isomers of 2,6-dimethyl-4-piperidone. The compounds were found to be artifacts formed by the reaction of the smoke components ammonia and acetaldehyde with the solvent acetone. Conditions which affected the yield of the artifacts from the processed CSC include pH, temperature, reaction time, and levels of ammonia and acetaldehyde present in CSC.

Abstract A flameless atomic absorption method has been developed which permits the quick determination of the levels of trace metals in cigarette smoke. The total particulate matter (TPM) was collected by electrostatic precipitation and dissolved in methanol before analysis. In order to trap the last remaining traces of metals, the gas phase was passed through microporous filters which were analysed direct. The sensitivity of this method for the metals studied (Zn, Pb, Cd, Ni) is good in both the particulate and gas phase samples, with the sole exception of Ni in the gas phase. Results obtained by the flame and flameless methods are compared.

A gas chromatographic method was developed to quantitatively determine the major components in the total particulate matter (TPM) of cigarette smoke. Tobacco smoke condensate was collected on a glass fiber filter and the components were converted to their trimethylsilyl derivatives and then subjected to glass capillary column gas chromatography. By this method, volatile and non-volatile tobacco smoke components, including unstable phenolic substances and water-soluble polyhydroxy compounds, were determined simultaneously

The methyl, multi-methyl, and ethyl derivatives of the polynuclear aromatic hydrocarbons (PAH) of cigarette smoke condensate (CSC) were isolated from the neutrals by silicic acid chromatography, solvent partitioning and gel chromatography. The procedure yielded a relatively pure PAH isolate amenable to further identifications. The multi-alkylated PAH were concentrated in the early gel fractions with parent and higher ring PAH found in subsequent gel fractions. It was shown that CSC is very rich in alkylated PAH, and their successful identification required extensive use of gas and liquid chromatography and ultra-violet and GC - mass spectrometric techniques. High-pressure liquid chromatography (HPLC) separated individual isomers of the alkylated PAH in complex GC peaks. PAH from indene to pentamethylchrysene were found. This report concludes our identification studies on the PAH of CSC and complements our two previous reports in this journal. Collectively, our studies have identified approximately 1000 PAH of cigarette smoke condensate and have led to the development of methods for the routine quantitation of PAH in smalI quantities of cigarette smoke condensate.

The percent incorporation of chlorogenic acid, chlorogenic acid oxidase (CAO), peroxidase (PRO) and Fraction I protein into the non-dialyzable fraction of acid-precipitated and acid-soluble brown pigments of tobacco was studied by use of ¹⁴C-precursors and appropriate substrates in the in vitro synthesis of brown pigments. The in vitro synthesized pigments showed the same gel permeation profiles as the brown pigments isolated from air-cured leaves. The incorporation of chlorogenic acid was correlated with its quantity in the reaction mixture, and a significant amount of incorporation appeared in the acid-soluble pigments which also correlated with browning intensity. The amount of protein fractions containing CAO and PRO affected the percent incorporation of radioactivity, but this was independent of chlorogenic acid concentration. In addition to the loss of CAO and PRO during the formation of brown pigments, the degradation of proteins, primarily Fraction I protein, occurred in the reaction mixture. The degradation products of Fraction I protein were recovered in both brown pigments. Results indicate that chlorogenic acid oxidation is the major factor for browning, and the degradation products of Fraction I protein and CAO and PRO contribute to the protein moiety of the pigments.

Abstract A new suggestion for the definition of pressure drop is submitted which was accepted by the ISO/TC126-SC1 committee and Coresta Technology Study Group. The various standard conditions under which the pressure drop is to be measured are substantiated individually. The suggestion is based on a thorough study of the literature (state 1976), which is cited, with sources. This report was published in English and French in: Coresta Information Bulletin 1977-1, 17-33.