The concentration of gas-vapour phase components of cigarette smoke increases almost throughout from the beginning to the end of each puff, as produced on a piston-actioned smoking machine. While this is not true for all substances examined in the 5th puff, it is obvious in the 3rd puff, and very pronounced in the 8th puff, where the increase in volatile components from the second to the last thirds of a single puff is important. This indicates without any doubt that the concentration in volatile components increases from the beginning to the end of a puff. This effect is increased as the smoking progresses towards the butt end of the cigarette. The yield of the crude smoke condensate is about the same in each third of a puff. In the last puff, however, the increase from the 2nd to the last puff third is very pronounced and is comparable to the increase in volatile smoke components from the beginning to the end of the puff.

The examined components in the volatile phase of cigarette smoke increase with the puff number, in the same way as does the smoke condensate. The variation progresses similarly whether sampling with the Grob syringe or the smoking machine. However, when using the syringe we obtain lower values.The amount of particulate matter on a Cambridge filter has little or no effect on the retention of the volatile phase components by this particulate matter, at least after the smoking of the first cigarette.The volatile phase, resulting from the total phase collected in the syringe, gives, with the exception of benzene and toluene, higher values than those obtained by direct sampling through a Cambridge filter, both in the complete cigarette smoke test and in the puff-by-puff test.By sampling the different puffs each time through a new Cambridge filter we observe that values are systematically lower than those obtained by aspiration of the respective puffs through one and the same Cambridge filter.

No abstract

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.

The activated carbon in a hollow, triple filter shows, under normal storage conditions, i. e. at a temperature of 21°C and 60 % relative air humidity, a decrease in the capacity for retention connected with the changed water content of the carbon. This loss of activity occurs during the first two weeks and subsequently remains practically constant even if storage lasts 6 months