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  • Author: J. F. Graham x
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Calculation of Retention Values and Selectivity Factors for Dual Filters

Abstract

Data are presented for the retentions and selectivity factors of a variety of filters, and a method of calculation of the resultant values for dual filters made up from these materials is described

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A Fraction Trapping and Transfer Device for the Analysis of Cigarette Smoke

Abstract

The device described has been developed in order to provide a separation of smoke condensate volatiles (B. Pt. range 50°-350°C) adequate for qualitative and quantitative analysis. The various disadvantages of the use of a single GLC column for this purpose are avoided by the use of a two-stage GLC process. Fractions are trapped from a primary column chromatogram, and transferred to a secondary column of different polarity, where a further separation is obtained. The processes of trapping and transfer are electronically controlled, and permit quantitative transfer of any fraction between the two columns, which are run under completely independent conditions. Examples of the separation obtained with cigarette smoke 'semi-volatiles' and also with vapour phase are given.

Open access
Cigarette Smoke Analysis by Computer - GLC

Abstract

A two-stage GLC system has been developed to produce a separation of cigarette smoke "semi-volatiles" into several hundred peaks per analysis. Quantitative measurements of the separated peak areas, with correction for baseline drift and an internal standard value, are made by an off-line computer, using a digital output obtained from the GLC system on punched tape. The main features of the computer program used are described, and typical output data are shown. Results of analyses dealing with cigarette smoke composition, and the selective effect of various filters, are presented. The use of neophytadiene as reference compound for the selectivity calculations is described

Open access
The Modification of Cigarette Smoke by Filter Tips

Abstract

One of the best known ways of modifying cigarette smoke is by the use of cigarette filters of various types. Filters are now being made from a variety of materials and, of recent years, have become more complex in structure and function. The authors consider the different ways in which different types of filters modify the chemical composition of the smoke showing some typical results. A new method of studying the range of higher boiling compounds in the smoke based on the volatilization of compounds trapped on a Cambridge Filter is discussed and information which this provides with different filter types is presented. Having shown the different action of the available range of filters as individuals, the possibilities of combining these in different ways to produce multiple filters and the degree of control of the smoke composition made possible as a result are discussed. If one examines the efficiency of any type of filter towards the whole range of substances in tobacco smoke from the permanent gases up to the high boiling compounds such as nicotine, one finds that the efficiency of the same filter varies widely according to the compound considered. Further, one finds that the pattern of efficiencies over the range of compounds is quite different between one filter and another. If, in the design of a filter cigarette, one wishes to emphasize or reduce various portions of the smoke it is possible to exercise a considerable degree of control by the use of suitable types of filter or combinations of filters. In addition to removing smoke constituents to varying degrees it is also possible to add desirable constituents to the smoke such as flavours by means of filters and the analytical technique mentioned above is very suitable for assessing the amount of such flavouring material which is actually present in the cigarette smoke

Open access