Volume 6 (1971): Issue 1 (July 1971)

The suitability of electric measuring methods making use of transducers has been tested for the smoking parameters puff duration, draw resistance, puff profile and puff volume. The procedures proved to be accurate, reproducible and technically simple and are, in our opinion, appropriate for calibrating smoking machines and for controlling the said parameters during the smoking process.

A study was made of the effect of the puff profile on yield and composition of the mainstream smoke of cigarettes smoked on a RM 20/68 smoking machine producing three different puff profiles (square-shaped profile, early peak and late peak profiles). The smoke was precipitated in an electrostatic trap. Crude condensate, dry condensate, smoke nicotine, phenols, puff number, and draw resistance were determined. Significant differences were found between the dry condensate yields of two puff profiles and between the nicotine and phenol yields of all the three puff profiles.

Six fractions of the steam volatiles of tobacco smoke condensate (semi-volatiles) are formed by column chromatography on silica gel. The constituents are identified by means of a combination of gas chromatography and mass spectrometry. About 320 compounds are indicated. Out of the 215 substances identified 69 have not been previously reported in cigarette smoke.

The quantitative determination of formaldehyde in the gas phase of cigarette smoke does not permit any conclusion about the actual level in whole smoke. This is due to the fact that a Cambridge filter charged with smoke condensate absorbs up to 50 % of the volatile aldehydes from the gas phase. A simple method is presented making possible the estimation of formaldehyde in whole cigarette smoke. The procedure is based on the Hantzsch reaction between formaldehyde, acetylacetone and ammonium ion in an aqueous buffer solution. The reaction product, 3,5-diacetyl1,4-dihydrolutidine, has an absorption maximum at 412 nm and is measured spectrophotometrically. The operations are simple and there are no separation steps required. Reproducibility is excellent and interference by other carbonyl compounds can be neglected. Acetaldehyde in concentrations 10 times higher than formaldehyde interferes to less than 1 %. Different types of cigarettes have been analysed with respect to their delivery of formaldehyde. Values found range from 40 to 90 µg per cigarette. The concentrations found in whole smoke are significantly higher than the values cited in the Iiterature for gas phase formaldehyde

Condensates obtained by smoking cigarettes, cigars and pipe tobacco have been compared on the basis of their abilities to reduce cytochrome c and DCIP. Most market brands of flue-cured cigarettes, while differing on the basis of total reducing activities, give similar values when reducing activity is expressed as specific activity (reducing activity per mg particulate matter). Condensates from blended cigarette brands containing other types of tobacco in addition to flue-cured, have lower specific activities. Special types, such as cigarettes made from 100 % reconstituted tobacco and a ventilated cigarette, also give lower values. Both cigars and pipe tobaccos give condensates with distinctly lower specific activities than those obtained from flue-cured cigarettes. In the case of pipe tobacco a large amount of water accumulates on the Cambridge pads and has to be taken into account when calculating specific activities.

Ethanolic extracts of tobacco and tobacco smoke contain compounds capable of accelerating the oxidation of ascorbate. Using a polarographic technique, smoke from cigarettes, cigars and pipe were examined for oxidising properties. Smoke from Virginia cigarettes showed greater activity than that from blended cigarettes, while smoke from cigars and pipes had even lower activity. The reaction of ascorbate and smoke has been shown by EPR to involve a radical intermediate.

The gas chromatographic method described here has been developed for the determination of low carbon monoxide concentrations in air and blood. For the determination in expired air, a 4 ml sample is injected in a molecular sieve 13X column, where the CO is separated from the other gases. The CO is then hydrogenated to methane over a nickel catalyst column heated to 290°C, and the methane is determined with a flame ionization detector. The limit of detection is 0.1 ppm CO in a total sample volume of 4 ml. The standard deviation per single determination is 0.04 to 0.08 ppm CO in the CO concentration range 0.2 to 10 ppm. For the determination in blood, the CO is liberated from the HbCO complex with K3[Fe(CN)6], transferred into a molecular sieve 5A column which is cooled in liquid nitrogen, and then swept into the gas chromatographic set-up used for the determination of CO in air. 0.05 % HbCO can still be detected in a 0.1 ml blood sample. The standard deviation per single determination is 0.02 % HbCO for a total of 1 % HbCO in the blood sample.

Freeze-dried and corresponding conventionally cured tobacco have been subjected to comparative studies. It is shown that the cigarettes manufactured from the freeze-dried tobacco have a noticeably lower average weight due to the higher filling capacity of this tobacco and that this has little or no influence on the taste, but affects the burning rate considerably. Determinations of the amounts of total particulate matter, dry condensate, and nicotine in the smoke shows that these are about half in the case of the freeze-dried material when an equal number of cigarettes are smoked; they differ much less when an equal amount of tobacco or an equal number of puffs are used as the bases for comparison. The "phenol" content of the smoke is however in all cases found to be noticeably lower for the freeze-dried cigarettes. Examination of the ciliotoxic effect of the smoke from the two types of tobacco on rabbit trachea in vitro shows that there is no significant difference between the number of puffs required to achieve complete ciliostasis. A detailed gas chromatographic-mass spectrometric study using a high resolution glass capillary column and computerised data-acquisition demonstrates that there are no significant differences between the gas phases of the smoke derived from the two differently treated tobaccos.

On the basis of numerous research results and data on the development of nicotine and condensate contents of German cigarettes, of their respective shares in the market, the smoked length of cigarettes, and of the pro capita consumption of cigarettes in the Federal Republic of Germany, an estimate has been prepared on the yearly pro capita consumption of smoke condensate and nicotine in the Federal Republic covering the years 1961-1970. The values for 1961 amount to 40.2 g of smoke condensate (crude) and to 2.04 g of nicotine. The values for 1970 are found to be only 29.4 g and 1.63 g respectively. That means that the consumption of smoke condensate and nicotine in the Federal Republic has decreased during the last ten years. The share of smokers having remained almost the same, the consumption of smoke condensate and nicotine per smoker is, as well, found to have decreased by about 27 % and 20 % respectively during the years between 1961 and 1970 despite an increased cigarette consumption.