Search

The present paper shows and discusses microphotographs of fibres used for the manufacture of cigarette papers as well as such photographs disclosing the composition of cigarette papers.

The influence of air permeability of cigarette paper on the yield of condensate and on its composition was examined. Total particulate matter and nicotine in the smoke decrease with increasing permeability of the paper. The decrease results from the smaller quantity of tobacco burnt in the mainstream. Higher combustion cannot be obtained by paper of greater permeability. The content of condensate of 3,4-benzopyrene is constant. Total particulate matter and nicotine in the smoke - measured in per cent of the tobacco smoked in the mainstream - are also constant.

Ten sorts of cigarette paper with differing physical properties, made of the raw materials Iinen, sulphate cellulose and “viskose”, which had been impregnated with citrate, phosphate or nitrate, were examined. The cigarettes made from these, which all contained the same blend of tobacco, were 7.95 × 80 mm and had an average weight of 1.070 g at 11.5 % moisture, were compared with each other in taste and in laboratory tests. A variation of the surface weight between 20.5 g/m2 and 24.5 g/m2 had no noteworthy influence on the properties of the cigarette. For the impregnation of the paper citrate is more desirable than the other salts investigated. The cigarettes made with paper impregnated with citrate provide the best looking ash and were favoured by the smokers of the taste panel. Cigarettes made with paper impregnated with nitrate and phosphate are stronger and more mordant and, furthermore, they have a bitter “after taste”, except those made with “viskose” paper. As the porosity of the paper increases the totaI condensate amount decreases. The “smouldering speed” of the cigarette increases somewhat. The members of the taste panel in each case preferred the milder cigarettes with the more porous paper. Paper made from linen, the most usual raw material nowadays for making cigarette paper, was compared with sulphate cellulose and “viskose” paper. Paper of sulphate cellulose is by comparison not very porous and gives the cigarette's taste tart qualities. “Viskose”, on the other hand, can be used to make very porous paper, the physical qualities of which come up to or even exceed those of linen paper. It was not possible to prove by the tests whether “viskose” paper negatively influences the taste of the cigarettes.

The ''porosity'' or ''air permeability'' of cigarette tissue is measured by many different instruments, is expressed in various units and it is frequently impossible to correlate such measurements and the readings of such instruments. The property of a paper whereby it allows air and gases to pass through it while still containing the burning tobacco rod is of great and increasing interest in both the Research Laboratory and Raw Material Control Laboratory of the cigarette and filter rod manufacturer. Interest in papers of higher air permeability continues to grow, particularly in regard to the so-called ''Health Hazards of Smoking", and thus the effect of smoke dilution. Such interest by the cigarette and filter rod manufacturer necessarily means that the paper manufacturer must pay especial attention to this property during paper manufacture and in development work. He also requires to define and measure the property in his control and research laboratories. Unfortunately, there is no common language to describe this property and as interest in higher porosities grows so the shortcomings of some methods of measurement are highlighted. The situation is further complicated by the need of control laboratories for robust, simple to operate instruments, while a research laboratory might be more interested in accuracy and precision, while being less affected by the demands of careful operation and manipulation. Likely sample sizes can also vary, from small spills cut from individual cigarettes or rods, through long narrow skeins to the papermakers' sheets. A standard definition of air permeability of a sheet of paper has therefore been proposed and an instrument has been designed, using this definition, to meet the requirements of all interested parties. A number of these instruments have been built and proved by practical usage

A simple method for the determination of the balance of carbon-14 activity added to cigarettes is described. The total recovery of activity is 80 % or greater, and the method can be used to obtain information on the transfer and pyrolysis reactions occurring when cigarettes are smoked.

A method for preparing cigarettes from ground tobacco is described and suggested as a simple means of comparing smoke yields of total particulate matter and nicotine. It is shown that yields from cigarettes made from ground and from cut tobacco are highly correlated.

According to the formulae the pressure drop R (l) and the degree of ventilation V (l) of cigarettes depend on the length l of the cigarette without tip, on the pressure drop RG of the incandescent zone alone, on the specific resistance to air flow b of the tobacco rod, on the specific conductivity a of the paper wrapping, and on the pressure drop RM of the ventilation-free cigarette tip. The parameters a and b are defined by the equations respectively, for the pressure drops RT and RP of the tobacco rod only and of the paper wrapping alone. In practice, the cigarette can approximately be considered as "ohmic" resistance to air flow, i.e. there is a linear relationship between pressure difference and flow rate. The degree of ventilation is the part of the total stream which penetrates the paper wrapping of the cigarette. The indicated relationships were theoretically deduced and empirically confirmed. The formula for R (l) corresponds to In general, there are the following relations where U1 is the total decrease of pressure occurring along both cigarette without tip and incandescent zone, I1 is the total stream leaving the cigarette at the cigarette tip, U2 is the decrease of pressure occurring along the incandescent zone, and I2 is the air stream which flows into the cigarette through the incandescent zone. The connections between U1, I1, U2, I2 and R, RG, V are as follows

Cholesterol-4-14C and b-sitosterol-4-14C were incorporated into cigarettes and their presence in mainstream smoke was studied. The transfer of 14C-labelled cholesterol to mainstream smoke was 20.27 %, of which 16.25 % was in trapped smoke condensates and 4.02 % in butts; only 0.004 % was in ashes. The transfer of 14C-labelled b-sitosterol to mainstream smoke was 16.20 %, of which 13.11 % was in trapped smoke condensates and 3.09 % in butts; only 0.007 % was in ashes. The relative composition of free sterols, steryl esters, and bound glycosides in cigarette tobacco and in trapped smoke condensates was also studied. Fractions of free sterols and steryl glycosides were higher while fraction of esters was lower in trapped smoke condensates as compared to cigarette tobacco. Comparison of four individual sterols (cholesteroI, campesterol, stigmasterol and b-sitosterol) was studied in cigarette tobacco and cigarette smoke (smoke condensates, butts, wrapping papers from butts). A slight increase of cholesterol was noted in smoke condensates and wrapping papers from butts.

There have been various references in the literature to the levels of trace metals in natural products (1., z, 3). There have also been references to the level of cadmium found in tobacco smoke (4). We have, in the past, accepted the published data of other workers in this field (5, 6) but recently we have made our own evaluation of the level of cadmiwn, nickel and lead in tobacco and cigarette smoke. The work described in this paper had two objectives: firstly to determine, using re

This paper describes a method for the extraction, separation and determination of amino acids, both free and protein-bound, which are present in tobacco. The introduction of the lyophilization process and the ''cold finger'' technique made it possible to obtain a good purification of extracts which, unlike the previous methods, have been preserved for a long time. The combined use of column chromatography and mass spectrometry enabled all amino acids present to be detected. The analyses carried out on different tobacco varieties showed certain quantitative and qualitative differences in the composition of amino acids and only small quantitative variations in the composition of protein-bound amino acids

The cold pentane traps of the precipitation procedure described in the preceding paper (cotton wool trap, water trap, pentane traps) favour the formation of N-nitroso components and, as a result, the emergence of artefacts. If, however, the smoke sojourns in the aerosol state for a period of 40 seconds (compared to 5 seconds) also that part of condensate of smoke from cigarette tobaccos rich in nitrates and bases which is trapped on cotton wool at normal temperature, contains N-nitroso-dimethylamine and N-nitroso-pyrrolidine in quantities corresponding to 0.004 µg N-NO per cigarette. The formation of N-nitroso components in the smoke of tobaccos of high nitrate and base contents accordingly occurs during a gas phase reaction which is dependent on time.In conformity with the previously reported findings N-nitrosomethyl-n-butylamine was identified in the condensate gathered in pentane traps. Presumably, it has however to be regarded as an artefact produced by the precipitation system employed. Condensates collected in cold and acetone traps were found to contain more N-nitroso components than condensates precipitated simply by the gas phase reaction of the smoke. The quantity of N-nitroso components contained in condensates gathered in cold traps was found to increase during aging.Model experiments with pure substances showed that the formation of N-nitroso components in the gas phase requires the presence of a mixture of NO and NOThe competitive reaction of dimethylamine and methanol with the gaseous mixture of nitrogen oxides displays the prevailing formation of N-nitroso-dimethylamine. The yield of N-nitroso-dimethylamine in NO-air-mixtures is probably only dependent on the rate of the oxidation NO undergoes to NONitramines cannot occur in smoke.

The present paper gives an account of tests carried out with the automatic ''Coleman'' apparatus to determine the nitrogen content of tobacco. Preliminary experiments made with different tobacco types led to the determination of optimum operating conditions which give exact and reproducible results. The values obtained by this procedure are the same as, or slightly superior to, those obtained by using the Kjeldahl method associated with the use of an efficient catalyst.

An automated smoking machine, and improved associated equipment, has been described. The automatic portion consists of a "string cut-off" technique which instantly and accurately stops the puffing action on cigarettes. This is achieved by an electronic sequence that deactivates three-way solenoid valves and vents the smoking train to the air at the syringe. Solenoid deactivation is achieved through the use of microswitches and relays. An automatic puff-counting unit records the number of puffs taken on the cigarettes on each port. The counters are pulsed by a signal generator set for 5 pulses per second. The generator is activated by a 2-second cam and microswitch attached to the 4-second cam that cycles the smoking machine. Constant puff volume and puff duration are maintained by use of individual syringe eccentric cams that allow precise volume adjustment on each port and solenoid valves that serve as intake and exhaust valves and provide positive action. The solenoid valves are activated by the 2-second cam and microswitch that is synchronized with the puffing downstroke of the syringe. The 2.0 AA± 0.2-second puff is precisely obtained through the machine's variable speed controlled gear driven electric motor. This feature yields a stable volume and duration regardless of the resistance of the cigarettes. The level of precision obtained previously on the O'Keeffe and Lieser machine was reduced by one-third by the automation developments described in this paper.

Three instruments usually employed for the determination of the diameter of cigarettes, i.e. a nonius instrument, a pneumatic instrument, and a circumference projector, are compared with an optical device developed in the author's laboratory. The latter enables the mean diameter of a cigarette to be determined over a length of 10 mm with an accuracy of AA± 0.0015 mm. With regard to cigarette manufacture, the differences of the results obtained for both cigarettes and filter rods by application of the optical device, of the nonius instrument, and of the pneumatic instrument, respectively, were found to be negligible. The diameter values obtained by means of the projecting apparatus were, however, shown to be too small by one paper thickness.

The present paper describes an automatic balance for the sorting and classification of cigarettes as developed by the collaboration of Mettler with the Brinkmann laboratories. The principle and the construction of the balance are described. The results shown permit a detailed discussion leading to the conclusion that the described automatic balance is a satisfactory instrument for the quality control in cigarette factories.

The present paper reports on experiences gained, in practice, by the use of the statistic apparatus type 611 of the firm of Güttinger. By means of transmitting keys the transistorized calculating machine permits the determination of mean values and standard deviations of ten classes comprising 99 pieces each. It is demonstrated that several classes can combine and that piece numbers exceeding the mentioned limit can be adjusted by division without diminishing significantly the accuracy of the resulting values.

The quantity of tobacco which is necessary for the correct filling of a cigarette depends on different factors and particularly on the filling weight (apparent density) of tobacco rag at a given pressure. Some years ago the ''Centre d'Essais'' of the SEITA developed an apparatus by which the filling weight being related to the filling capacity can be measured. The present paper describes the apparatus and its working conditions and deals with the causes of errors by which the measurements can be influenced.

During the last three and a half years remarkable progress has been made in tobacco and tobacco smoke research. The fact that tobacco and smoke constituents of interest generally occur in extremely low concentrations necessarily led to the development of sophisticated analytical methods which were found to be of general interest in microanalysis. The composition of the gaseous phase of tobacco smoke is by now well known owing to studies using a combination of high resolution gas chromatography and mass spectrometry. A great many compounds were identified for the first time in tobacco or tobacco smoke by means of analytical procedures newly developed or adapted from other research fields. Terms concerning the distribution of the total smoke to the different smoke streams have been defined, and the possibilities of selective retention of smoke components have been examined. The distribution of water consisting of tobacco moisture and of combustion water among the different smoke streams and other transportation phenomena in the burning process of a cigarette have been studied. Particle size distribution, the determination of the air permeability of cigarette paper, and the mechanical properties of tobacco have been investigated by means of physical measuring procedures.

Asmus et al. have published an analytical procedure for the quantitative separate determination of nicotine and pyridine in tobacco smoke. Their method has been slightly modified in order to adapt it to the standard procedure of smoke alkaloid analysis. The modified method allows the accurate determination of the nicotine alkaloids and the pyridines; the latter can be assayed with a precision of ± 0.7 µg per cigarette, for a total of 21 µg pyridine per cigarette (95 % confidence limits). Preliminary results using this method indicate that the mainstream smoke of one cigarette contains between about 20 (sun-cured and flue-cured tobaccos) and 50 (air-cured tobaccos) µg of pyridine. The stub of a straight cigarette shows a marked retention efficiency for smoke pyridine; still better retention is observed through a cigarette filter from cellulose acetate, whereas filters on a paper or cellulose basis are less efficient. It is usual to separate the pyridines from the other smoke bases by steam distillation in presence of acetic acid or a buffer solution. It is shown that this procedure is inefficient. The simple pyridines contributing rarely more than 2 percent to the mass of the total smoke bases, there seems to be no real necessity of determining their amount in the course of a routine determination of the smoke alkaloids.

Carbon monoxide is found in the gas phase of cigarette smoke in relatively high quantities. In the present study a quantitative method for the determination of carbon monoxide in tobacco smoke by gas chromatography was used. The construction of a calibration line by means of carbon monoxide produced in the laboratory is indicated and the experimental procedure is described. Furthermore the relation between the carbon monoxide content in smoke and different parameters of the test cigarettes is evaluated. The carbon monoxide content in the smoke of various tobacco blends is determined. An increase of the carbon monoxide content in the smoke is observed after the extraction of sugars from the tobacco. The carbon monoxide content increased from puff to puff when the cigarettes were smoked. Cigarette weight had no influence on carbon monoxide in the smoke. This applies also to the humidity of the tobacco, the acetate filters and the carbon filters. Puff volume and the perforation of cigarette paper, however, influenced the carbon monoxide yield considerably.

The experimental results indicated in the present paper reveal that among all humectants admitted 1,3-butyleneglycol alone has marked fungicidal properties satisfying the requirements of practical tobacco treatment, and that, on the other hand, diethyleneglycol and glycerine practically do not have such qualities

Two methods of determination of the tobacco humidity - oven drying and azeotropic distillation with benzene - have been compared. The precision of the latter method had been formerly established on a model system of paper plus added water; it is shown that the precision is the same when the method is applied on tobacco.

The present paper shows the detectable factors on which a sorption isotherm depends. Even if it is well-known that a sorption isotherm is most essentially conditioned by influences of the respective tobacco variety, other factors, such as temperature, initial moisture content, or fibre dimension, play a part as well. In general, a sorption isotherm constitutes a ''summation'' of such factors and, in the end, a combination of desorption and adsorption if the tobacco is dried or moistened from the average commercial moisture content. The tobacco hysteresis is experimentally investigated and discussed

A method for routine determination of the pH in tobacco smoke is described which is to be preferred to the measurement by indicator paper as it is more exact and reproducible, and furthermore, it can be used at the same time for determining the buffering capacity of the smoke. The dependence of the results on various influences is discussed

This paper reviews

In two papers, Hoffmann and Wynder have described an analytical method for the quantitative determination of some phenols in the smoke of cigarettes. An application on cigarette filters permitted the statement that these filters may selectively retain phenols from the smoke. It is shown here that the analytical method has a limited precision and accuracy, sufficient to ascertain the effect of selectivity, but insufficient to detect relatively small differences between filters of similar retention capacity. It is shown that the interpretation of the results given by Hoffmann and Wynder is facilitated through the introduction of the notion of ''relative phenol retention'', i. e. the quotient of the ''phenol retention" to the ''T. P. M. retention'', whereas the ''selective phenol reduction". i. e. the arithmetic difference between these two criterions, is inapt to express the capacity of specific selectivity of a given filter, especially if the pressure drop of this latter is unknown. When classifying the filters studied by Hoffmann and Wynder according to their "relative phenol retention'', one arrives at different conclusions than these authors.

Compared with other methods the nitrate determination by means of a photometric method using 3,4-dimethylphenol ("Maastricht") proved to be most suitable for tobacco. 134 varieties of raw tobacco were examined. Virginia tobaccos were found to be low in nitrate content. Generally they contain less than 0.1 % nitrate. Oriental tobaccos were found to contain between 0.2 and 0.4 % of nitrate, while the nitrate contents of Burley tobacco range from 1 to 5 %. Nitrates are enriched in the mid ribs of tobacco leaves. The formation of nitrogen oxides in tobacco smoke is probably due to the nitrate content of tobacco exclusively as is shown by a determination of nitrogen oxides in the smoke of a paper cigarette impregnated with ammonium oxalate. Possibilities are discussed for reducing the nitrate content of tobacco mixtures.

An automatic apparatus is described for the detection of irregularities in the tobacco filling of cigarettes. The cigarette is drawn between two rows charged with a defined pressure, and the deformation of the cigarette transversely to its axis is enregistered on a paper band advancing with the same speed as the cigarette. When the deformation exceeds a predetermined limit, a leak is enregistered on an electric counter. The extent of the deformation, for a given cigarette type, is a function of the cigarette weight, the humidity of the tobacco and the pressure on the rows; these factors must be investigated before the cigarettes are tested on the apparatus.

A device is described which allows the separation of tobacco from cigarettes at a rate of 2000 cigts/hour whilst the cigarette paper remains intact