- Detalles de la revista
- Publicado por primera vez
- 01 Jan 1992
- Periodo de publicación
- 4 veces al año
- Acceso abierto
Composition Studies on Tobacco XXXVIII: Evidence for the Origin of the High Molecular Weight, Acidic Pigment in Cigarette Smoke Condensate
Páginas: 97 - 103
The yields of acidic brown pigment isolated from cigarette smoke collected and stored under various conditions show no significant differences; however, some tendency may exist for a small increase in yield on extended storage of the condensate in traps at -79°C or in acetone solution at room temperature. The molecular weights of subfractions of the pigment are variable when the pigment is immediately isolated from freshly prepared condensate. Storage of condensate results in a higher proportion of high molecular weight subfraction in the pigment in all cases. Both leaf and condensate pigments sublime at high temperature and low pressure yielding a sublimate that contains some subfractions with molecular weights of the same general magnitude as those in the isolated condensate pigment. Nicotine may be acquired as a moiety in the condensate pigment through artifact reactions in the collection system or during the isolation. However, the nicotine acquired in this way apparently represents a very small amount of the total saponifiable nicotine in the pigment. The acetic acid moiety of the condensate pigment is not acquired by such artifact reactions. Although part of the condensate pigment structure may be formed through reactions in the collection system or during isolation, no evidence was obtained that the condensate pigment is largely an artifact.
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Composition Studies on Tobacco XXXlX: Changes in Smoke Composition and Filtration by Artificial Alteration of Smoke pH: Formic and Acetic Acids and Volatile Phenols
Páginas: 104 - 108
The levels of formic and acetic acids in the free acid and salt forms in unfiltered smoke are reduced when smoke pH is lowered from 5.6 to 4.2 using lactic acid as the cigarette additive. The acid levels are increased markedly when unfiltered smoke is alkalinized to pH 8.2 using dipropylamine as the cigarette additive. The variability of the analytical method prevented detection of small degrees of selective filtration of the acids. Although indications of selective removal were obtained in smoke of pH 4.2-7.9, using cellulose acetate filters with or without activated carbon, the variability did not permit a firm demonstration of this effect with one exception: a distinct selective removal of acetic acid was observed in smoke of pH 4.2 using a multiple filter. The use of formic acid as a cigarette additive to lower the pH of unfiltered smoke results in a significant increase in the major phenols therein. No change in levels of smoke phenols is observed when dipropylamine is used as a cigarette additive to alkalinize the smoke. An increase in selective removal of smoke phenols occurs when smoke pH is depressed from 5.8-6.1 to 4.4-4.9 using filters of cellulose acetate with or without activated carbon. Selectivity is lost when smoke pH is raised to 7.9 using the alkaline cigarette additive.
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Composition Studies on Tobacco XL: Large Scale Fractionation of the Neutrals of Cigarette Smoke Condensate Using Adsorption Chromatography and Solvent Partitioning
Páginas: 109 - 114
Ten successive 1 kg samples of cigarette smoke condensate were prepared and the neutrals were removed by solvent partitioning of each kg. After removal of a control sample (41.2 %), the remainder of the neutrals were separated by adsorption chromatography on silicic acid followed by partitioning of the eluates between polar and nonpolar solvents, yielding a total of 10 fractions for biological study. A range of recoveries from 94-109 % of the neutrals was obtained in the ten successive runs; the overall average recovery was 102 %. Small amounts of strongly adsorbed material not eluted from the adsorption columns by the technic could be removed in part by other procedures. Using this method, benzo[a]pyrene was concentrated to a high degree in one fraction, thus permitting the detection of biologically active nonpolynuclear agents in the other fractions on bioassay. Exclusion of light during separation did not alter significantly the benzo[a]pyrene levels obtained in the polynuclear-enriched fraction.
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Páginas: 115 - 133
Knowledge of tobacco smoke composition grows rapidly by application of modern analytical methods. Hitherto, 181 nitrogen compounds are known comparable to 50 in 1959, comprising 24 aliphatic amines, 19 aromatic amines, 7 nonaromatic N-heterocyclic compounds, 26 pyridine bases, 6 other aromatic six-membered N-heterocyclic compounds, 2 pyrroles, 15 other aromatic five-membered N-heterocyclic compounds, 12 pyrazines, 16 tobacco alkaloids and compounds with two nitrogen rings, 15 amino acids, 16 nitriles, 6 nitroalkanes, some derivatives of nitrous acid, inorganic cyano compounds, nitrogen oxides, ammonia, and elemental nitrogen. The balance of all the nitrogen compounds in tobacco smoke condensate gives a hint at the occurrence of unknown neutral N-compounds.
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Temperature-Yield Profiles of Tobacco and Tobacco Constituents. II. Yields of Phenol and Cresols from Untreated and Borate-Treated Cellulose and Lignin
Páginas: 134 - 139
The data obtained from the isothermal pyrolysis of untreated and borate-treated cellulose and lignin show that borate salts influence the yields of phenol, o-cresol, and m-,p-cresol from these two tobacco leaf constituents. The observed differences between the level of phenol from tobacco and borate-treated tobacco can be at least partially attributed to the effect of borate salts on the pyrolysis of lignin and cellulose. It must be emphasized, however, that the contribution of cellulose and lignin to the formation of phenol and cresols obtained from the pyrolysis of tobacco should not be quantitatively compared with the level of phenol and cresols obtained from the pyrolysis of pure cellulose and lignin. This is also true of borate-treated cellulose and borate-treated lignin. The main conclusion from this study is that borate salts do affect the recovery of phenol and cresols from leaf constituents such as lignin and cellulose and may be partially responsible for the increased levels of phenol obtained from the isothermal pyrolysis of borate-treated tobacco.
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Chemical Studies on Tobacco Smoke. IX: Quantitative Analysis of Chlorinated Hydrocarbon Insecticides
Páginas: 140 - 148
An analytical method was developed for the qualitative and quantitative determination of chlorinated hydrocarbon insecticides in tobacco products. It is based on three consecutive liquid-liquid distributions, followed by column chromatography on deactivated alumina. This procedure leads to a degree of enrichment which permits the direct assessment of the insecticides by gas chromatography. For the isolation and identification of the individual components the column chromatography endfractions are separated by gas chromatography and collected from the effluent of the column. These materials are used for mass spectrometric analysis. For the quantitative analysis C14-labelled DDT is employed as internal standard and the amount of insecticides is determined with the aid of a gas chromatograph with an electron capture detector with a sensitivity for chlorinated insecticides of 1 nanogram (10-9 g). In 1.0 g cigarette tobacco were found 11.7 µg 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane [DDD]; 4.8 µg 1,1-dichloro-2-(o-chlorophenyl)-2-(p´-chlorophenyl)ethane [o,p´-DDD]; 7.8 µg 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane [DDT] and 3.6 µg of an admixture of 1,1,1-trichloro-2-(o-chlorophenyl)-2-(p´-chlorophenyl)ethane [o,p´-DDT] and 1,1-dichloro-2-(m-chlorophenyl)-2-(p´-chlorophenyl)ethane [m,p´-DDD]. The mainstream smoke of an 85 mm U.S. blended cigarette without filter tip contained 1.75 µg DDD, 0.45 µg o,p´-DDD, 0.81 µg DDM, 0.77 µg DDT, 0.70 µg o,p´-DDT plus m,p´-DDD, 0.21 µg 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene and 0.21 µg 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene [DDE] and 1.52 µg trans-4,4´-dichlorostilbene [trans-DCS]. Endrin was neither detected in cigarette smoke nor in commercial U.S. tobacco samples purchased during the winter 1967-68. The transfer rates for unchanged chlorinated insecticides from cigarette tobacco into mainstream smoke were 18 % for DDD, 11.6 % for o,p´-DDD and 12.4 % for DDT. The extraction of tobacco with n-hexane does not yield a complete extraction of chlorinated insecticides. A study in which a single leaf of a tobacco plant was sprayed with C14-labelled DDT indicated that the insecticide to some degree permeates the tobacco plant by diffusion into the lower layers of the leaf. In tobacco smoke condensate, which is exposed to sunlight or white laboratory light, one pyrolysis product of DDD and DDT, trans-4,4´dichlorostilbene, is photoisomerized to its cis-isomer. In an in vitro test cis-4,4´-dichlorostilbene was found to be dehydrogenated in air up to 0.5 % to 3,6-dichlorophenanthrene. Pyrolysis experiments at 880°C with DDD and DDT have been discussed briefly. In addition to components already found in cigarette smoke, chlorobenzene, the highly reactive 9-methylenefluorene and tentatively 1-chloro-2,2-(p-chlorophenyl)ethane as well as 3,6-dichloro-9-chloromethylfluorene were identified in the pyrolyzate. The findings of this study are compared with earlier investigations and discussed in respect to the formation of some of the chlorinated aromatic hydrocarbons. Animal studies are needed to evaluate the possible tumorigenicity of the major pyrolysis products of DDT and DDD.
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Páginas: 149 - 153
Effects of sucker control chemicals on cell division and differentiation were studied by observing changes in root-tip cells continuously submerged in 5 × 10-3M solutions of MH-30 (maleic hydrazide), fatty ester T-43 (methyl caprate), fatty alcohol T-148 (mixture of 1-octanol and 1-decanol), Penar (dimethyldodecylamine acetate), and surfactants Tween-20 (polyoxyethylene sorbitan monolaurate) and Tween-80 (polyoxyethylene sorbitan monooleate). No adverse cytological effects were induced by surfactants. Meristematic cells treated with MH-30 appeared to be normal but there was no cell division. MH-30 also caused fragmentation or duplication of nuclei on differentiating cells. The effects of fatty materials (T-43 and T-148) include immediate swelling of the nucleus and then a general cessation of cell division. Penar caused enlargement of differentiating cells and nuclear fragmentation or duplication, a higher frequency of binucleate cells was found to be induced by Penar than T-148 or even MH-30. In general, sucker control compounds tested in this study induced a rather low incidence of endomitotic action which was limited to certain differentiating cells.
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Fluidics and its Usage for Tobacco Processing/Pneumonik und ihre Anwendungen in der Tabaktechnologie
Páginas: 154 - 165
In recent years, new components have been used for numerous regulating and control functions: fluidic elements. These are switching and amplifier elements operated by means of low-pressure air and suitable for setting up logic circuits. This new line of technology, fluidics, also may be usefully applied to tobacco processing. This report therefore is intended as a preliminary guidance into the subject. An introductory chapter compiles the necessary basic features of control technics as far as these may be helpful to the understanding of the following description of fluidic elements. The first part of the main chapter deals with fluidics in general. Out of the variety of the different types only the two most important ones are considered: the jet-deflection and the turbulence affected fluidics. Design and functioning of both types are thoroughly discussed. The second part of the main chapter displays some applications in the field of tobacco processing. For the control of tobacco rod filling, emphasis is laid especially on the principle of measurement, whereas signal-controlled processing is only dealt with in short. A detailed description of the further processing of the signal is given for the example of a cigarette end scanner. Inspection at a packer on availability of all materials finds a particularly fine solution when applying turbulence-affected fluidics. In addition, a further example shows level control of fluids in storage tanks. In conclusion, some comparisons of fluidic elements against each other as well as against other control elements are given.