Volume 10 (1980): Issue 2 (July 1980)

Apparatus and procedures were developed to measure condensate, nicotine, water, carbon monoxide and carbon dioxide in mainstream and sidestream smoke. These were used to determine the effect of air dilution through filter ventilation on mainstream and sidestream smoke composition. It was found that there is a gradual transition from 'puffing combustion to smoldering combustion as the amount of diluting air entering the system increases. This is directly related to the decreased puff volume at the cone and decreased amount of tobacco consumed per puff. On a per· gram of tobacco consumed basis, sidestream combustion product formation is not changed but the amounts of carbon monoxide and water in the mainstream are decreased, as ventilation increases.

Nitric oxide in cigarette smoke was conveniently determined by non-dispersive infrared analysis (NDIR). Recoveries of 95 % were obtained with standard gas-air mixtures but recoveries from smoke increased from 87% for high-yield to 91 % for low-yield cigarettes. Relative error was about 4 %. A reduction in the dead volume of Cambridge filter cassettes, to reduce the amount of NO reacted between puffs, increased NO deliveries of cigarettes by 4%. Deliveries of NO were estimated to average 4 % lower due to oxidation, but reaction with other smoke components reduced them further depending upon concentrations. The NO deliveries of cigarettes increased as blend nitrate increased and as the flow of air around cigarettes decreased. Nitric oxide in smoke and in standard gas-air mixtures, determined by non-dispersive infrared (NDIR) spectroscopy, was substantiated by an automated colorimetric analysis. Interfering smoke species were determined and circumvented in both methods.

Our previously developed method for the determination of three-ring and larger polynuclear aromatic hydrocarbons (P AH) of cigarette smoke was modified to allow quantitative determination of the more volatile P AH. Recovery tests with 14C-naphthalene showed that this smoke P AH was being lost to a large extent during the usual solvent evaporation steps. Special solvent removal techniques, using very efficient distillation equipment, were developed and tested to quantitatively recover the naphthalenes. The gas chromatographic profile for the volatile P AH, including naphthalenes, fluorenes, and related compounds, is discussed in relation to the modified procedure. Quantitative values for some of the PAH of cigarette smoke are given. The developed solvent removal and concentration techniques should be most applicable to the analysis of environmental samples containing volatile compounds.

We have described a method for determining the HCN delivered in whole cigarette smoke and in smoke condensate extracted from filters. The method is simple, rapid and precise. It eliminates many manual operations and is semi-automatic.

The impinger tube/gas chromatograph sampling technique has distinct advantages in specificity, simplicity and accuracy over the older literature methods for airborne nicotine sampling and analysis. The impinger/GC method was found to be useful in determining nicotine concentrations in both low and high nicotine environments.

A special study was conducted with the aim of evaluating the effects of pesticide treatment on tobacco in comparison with tobacco not treated with any pesticide. For the purpose of growing these tobaccos, experimental plots were selected on Prince Edward Island, Canada, where contamination of air, soil and water was at a minimum. The tobacco leaf was analyzed for 35 components and 28 pesticide residues. These samples are to be used for smoke analysis and bioassay. The results will be reported in a later publication.

The effect of maleic hydrazide (MH) per se on bright tobacco was determined by comparing plants treated with MH to those without MH under conditions of good chemical sucker control. Sequential applications of each of five contact-type agents with MH one week later (Group I) were compared to dual applications of each of the same contact agents (Group II). In Group II suckers missed during applications were individually wetted to ensure excellent control. Sucker control was measured as 95 % for Group I and assumed to be 99 % for Group II. There were no agronomic differences between Groups I and II. In the visual warehouse appraisal, there was only a statistical difference for thin-bodied tobaccos between the two groups and a trend for slightly more heavy-bodied tobaccos in Group I. The chemical and physical analyses showed that filling value at 13 % moisture and equilibrium moisture content (EMC) measured at 60 % relative humidity were significantly lower in Group I than Group II. The result for EMC was questioned. Actual values for total alkaloids, total volatile bases minus nicotine, total ash, and alkalinity number of water-soluble ash were lower and reducing sugars were higher where MH was used. Except for EMC, the findings in this study reflected those established in studies where MH-treated and normally hand-suckered tobaccos were compared, but the differences here were generally not as great.

Soil samples collected approximately 21 days after pretransplant applications of ethoprop to flue-cured tobacco land contained residues averaging 0.54 and 1.13 ppm, respectively, for the 6.7 and 13.4 kg/ha rates. In contrast total residues of disulfoton (disulfoton plus three metabolites) averaged 0.28 and 0.54 ppm at 3.4 and 6.7 kg/ha rates. Concentrations of both compounds decreased with time at each of two locations. Residue levels of ethoprop in the first harvest of flue-cured tobacco from the Central Crops Research Station (Clayton, North Carolina) were 0.04, 0.02, and 0.08 ppm; from the Upper Piedmont Research Station (Reidsville, North Carolina), residues were 0.20, 0.16, and 0.27 ppm, respectively, for rates of 6.7, 6.7 combination (with disulfoton), and 13.4 kg/ha. Residues declined in succeeding harvests. Total residues of disulfoton plus three metabolites in the first sample of tobacco harvested from Central Crops averaged 2.52 and 1.89 ppm; and from Upper Piedmont residues averaged 10.24 and 6.50 ppm, respectively, for rates of 3.4 and 6.7 kg/ha. The residues declined in succeeding harvest and were 0.14 ppm or less by the fourth harvest at Central Crops and 0.08 ppm or less by the fifth harvest at Upper Piedmont.

The transfer during smoking of pesticides contained in tobacco into the smoke and the filter of cigarettes was investigated. The overall transfer into the mainstream smoke was 17 %. It was found to be independent of the type of the tobacco blend (American, Maryland, Virginia and Oriental). The pesticide retention of the following four filters was investigated: cellulose filter, cellulose acetate filter with low and high pressure drop, and a charcoal filter, characterized by nicotine retentions of 38 %, 27 %, 48 % and 54 %, respectively. The corresponding pesticide retentions found were 40 %, 21 %, 39 % and 38 %, i.e. lower than the nicotine retention in the cellulose acetate, and significantly lower in the charcoal filter. A 3 % degradation of p,p'-DDT and o,p'-DDT contained in tobacco to p,p'-DDE and o,p'-DDE respectively, was also observed. The pesticides initially contained in the tobacco part of the cigarette butt decreased during smoking. This appears to be the result of some initial condensation of substances carried through by the smoke stream (as indicated by the presence of pesticide degradation products), followed by strong desorption during the very last puffs.

A rapid, reliable and inexpensive method for the determination of inorganic bromide in cured tobacco is presented. The method features a unique CrO₃ selective oxidation with steam in Markham stills. The results by this method have been compared with five other methods. The reliability of the distillation method is shown by the recoveries of spiked samples at a mean of 97.8 %. The average standard error of ± 0.03 mg g^-1 indicates an acceptable level of precision. No loss of bromide takes place in the ashing process.