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Zeitschriftendaten
Format
Zeitschrift
eISSN
2719-9509
Erstveröffentlichung
01 Jan 1992
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 10 (1979): Heft 1 (December 1979)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2719-9509
Erstveröffentlichung
01 Jan 1992
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

10 Artikel
Uneingeschränkter Zugang

Design Criteria for Ventilated Filters

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 1 - 6

Zusammenfassung

Abstract

A number of filters were studied to determine the effect of air dilution on smoke filtration, both in well characterized acetate tow items and also in commercial filters that incorporated air dilution. A direct reduction of condensate and nicotine was observed in proportion to the degree of air dilution. Particulate filtration efficiency increased with air dilution. Gas phase delivery of aldehydes and CO decreased in greater proportion than the amount of air dilution. The commercial brands tested closely fitted the model developed in the filter tow study, except where mouthpieces or other flow channeling devices altered the filtration characteristics of the cigarette in varying degrees. Significantly, the results of the studies showed that the amount of air dilution, and not the physical means of air mixing, was the defining parameter to predict filter performance. Ventilation gives a useful design capacity that extends control of smoke filtration behaviour. By appropriate selection of tow denier per filament, total denier and cross-section shape, filter length and diameter, and the level of air dilution, filter properties can be adjusted to control gas and particulate phase deliveries, and the proportionality between the two.

Uneingeschränkter Zugang

The Use of Pressure Drop Measurements for Estimating Ventilation and Paper Porosity

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 7 - 16

Zusammenfassung

Abstract

Equations for calculating dilutions in vented cigarette filters and tobacco columns from pressure drop measurements are derived. These calculated dilutions are found to agree closely with those directly measured for a variety of commercial and experimental cigarettes wrapped with perforated and porous tipping and with different cigarette papers. The effect of hole placement on dilution and cigarette pressure is estimated. The effects of filter dilution on particulate matter, condensate and carbon monoxide delivery are discussed. A method for measuring filter dilution during smoking by means of pressure drop measurements is outlined and results for a typical vented filter cigarette are shown and discussed. The use of pressure drop measurements for estimating paper porosity and amount of dilution in the tobacco column on finished cigarettes is out-lined. The dilution obtained by this method was generally higher compared to the results found by a model based on a capillary flow regime, which suggests that flow through ordinary cigarette paper is a combination of capillary and orifice flow. The non-destructive nature and simplicity of pressure drop measurements make this method of measuring dilution useful in quality control of cigarette production.

Uneingeschränkter Zugang

Studies on the Natural Smouldering of Cigarettes: III. Determination of the Thermal Properties of Tobacco Shreds Packed in Columns

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 17 - 23

Zusammenfassung

Abstract

The values of effective thermal conductivity, specific heat and thermal diffusivity of various kinds of tobacco shreds, which are necessary for the solution of heat transfer problems of a smouldering cigarette, were determined. Effective thermal conductivity of tobacco shred packed into simulated cigarette columns was measured by a transient hot-wire method as a function of packing fraction at conditions of 20°C and 60 % relative humidity. Specific heat was measured with the aid of a differential scanning calorimeter (DSC). The thermal diffusivity was obtained from the values of effective thermal conductivity, specific heat and packing density. Effective thermal conductivity increased with increasing packing fraction (1 - e) and was uniformly expressed as a function of the total void fraction (et) inside the column regardless of tobacco types and stalk positions, whereas thermal diffusivity decreased with the packing fraction. At the same packing fraction, bright shreds produced higher values of effective thermal conductivity as well as higher specific heats (although specific heat was independent of the packing fraction) but had lower thermal diffusivity values than Burley and Matsukawa shreds.

Uneingeschränkter Zugang

A Unified Smoking-Automated Calorimetric System for the Analysis of the Gas Phase of Cigarette Smoke and its Application to the Determination of Hydrogen Sulfide

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 24 - 30

Zusammenfassung

Abstract

A system has been developed wherein the gas phase produced on smoking a cigarette through a Cambridge pad is analysed, on a puff-by-puff basis, for a desired component using automated colourimetry. The system consists of an AutoAnalyser I and a simple, 1-port smoking machine. The continuous gas stream from the smoking machine, either gas phase or intervening air, is passed concurrently with a stream of absorbing solution through a glass coil. Following passage through the coil, the solution is separated from the gas stream and introduced into the AutoAnalyser for continuous measurement of the concentration of the absorbed component. The entire system is calibrated using standard gas mixtures puffed in the same manner as the cigarette. The puff profile is essentially rectangular. Chief benefits expected from use of this system include the ability to obtain puff-by-puff measurements, a minimum time for reaction to occur in the gas phase and essentially no sample handling other than smoking the cigarette. The system has been utilized for the determination of hydrogen sulfide in gas phase using 0.1 N NaOH as the absorbing solution and the "methylene blue" colourimetric reaction. Results obtained on a variety of commercial U.S. brands ranged from 18 to 50 µg of H2S per cigarette, similar to results reported by other investigators using wet chemical methods. The accuracy of the results is supported by recovery tests wherein gaseous H2S added to the gas phase is completely recovered. The average relative standard deviations obtained with 11 U.S. commercial or reference cigarette samples using random selection of the cigarettes is 10.8 % for µg of H2S per cigarette and 8.8 % for µg of H2S per puff for a single cigarette. The basic system is thought to be applicable to the determination of a number of other components in gas phase.

Uneingeschränkter Zugang

Composition Studies on some Varieties of Tobacco and their Smoke: I. Major Components in Smoke Condensate

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

The relative proportions of the major smoke components and N-containing components in the semi-volatile phase and the non-volatile phase from some varieties of tobacco, i.e. flue-cured, Burley and Turkish tobacco, were determined. In flue-cured tobacco smoke, 2-furfural, 5-methylfurfural, 5-hydroxymethylfurfural and other carbohydrate pyrolysates, catechols and organic acids were present in higher concentrations than in the smoke from the other tobaccos. In Burley tobacco smoke, myosmine was present in much higher concentration than in the smoke from the other tobaccos. In Turkish tobacco smoke, glycerol and β-methylvaleric acid were both present in much higher concentrations.

Uneingeschränkter Zugang

Dihydro-γ-pyrones in Tobacco SmokeIdentification of 2,3-Dihydro-5-hydroxy-6-methyl-4H-one in the Smoke of Cigarettes from Burley, Virginia and Oriental Tobacco/Dihydro-γ-pyrone im Tabakrauch: Nachweis von 2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-4-on in Rauch von Cigaretten aus Burley-, Virginia- und Orienttabaken

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 39 - 47

Zusammenfassung

Abstract

2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-one [I] has been identified as a new cigarette smoke constituent. The concentration of substance I and of the homologous compound 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one [II] - determined in the smoke of Oriental, Virginia and Burley leaf - varies according to the type of tobacco. The amounts of substance I are 26, 20 and 6 µg a cigarette in the smoke of Oriental, Virginia and Burley tobaccos, respectively. For compound II the corresponding figures are 11, 13 and 4 µg a cigarette. Substance I is a new flavour compound which has a caramel odour with fruity overtones. This is undoubtedly important for the aroma of tobacco smoke. However, the presence of dihydro-γ-pyrone I in tobacco smoke is of theoretical interest as well. It is a cyclic enolone and has a structure similar to that of maltol and the cyclopentenolones, which we identified in tobacco smoke some time ago. Based on the similarity of structures we want to put forward the working hypothesis that a majority of the aroma substances in tobacco smoke have the constitution of an alicyclic or O-heterocyclic enolone containing a carbonyl and a C-alkyl (methyl or ethyl) group.

Uneingeschränkter Zugang

Some Factors Influencing Tobacco Leaf Senescence

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 48 - 56

Zusammenfassung

Abstract

Tobacco leaf disks were subjected to various types of lighting and chemical solutions to determine the interaction of these factors in leaf senescence. Far-red light promoted senescence more than light of lower wave-lengths. Magnesium at 50 mM was a potent inhibitor of senescence, whereas EDTA-disodium salt at 50 mM promoted senescence in the light but retarded senescence in the dark. Additional work with the effect of ethylene on detached leaves demonstrated that hydrolytic enzyme activity for amylase, peptidase and protease increased as a result of treatment but esterase activity decreased. The response differed with regard to variety and leaf maturity. Exposure to ethylene increased chlorogenic acid oxidase in lower leaves of pale yellow tobacco but decreased the enzyme in NC-95 lower leaves. These data relate to the growth behaviour of the two genotypes in that physiological maturity occurs at considerably different rates in pale yellow and NC-95 plants. The results help to explain why leaves of pale yellow plants tend to ripen within a much shorter time than leaves of conventional green tobacco cultivars.

Uneingeschränkter Zugang

Polyphenol Accumulation in Chlorophyll Mutants of Tobacco under Two Cultural Practices

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 57 - 64

Zusammenfassung

Abstract

Quantitative variation in plastid pigments and polyphenols during leaf growth and after curing have been studied with several chlorophyll-deficient genotypes of tobacco. Under culture for flue-cured tobacco, the chlorophyll-deficient pale-yellow (NC95-Py) and yellow-green (SC58-yg) lines did not differ in polyphenol accumulation from the corresponding normal green recurrent parents NC95 and SC58. A negative correlation was evident between concentrations of polyphenol and chlorophyll. Decrease of the latter during leaf growth was accompanied with a decline of PPO and PRO activities. When the chlorophyll-deficient genotypes were grown under conditions for Burley tobacco, concentrations of chlorophyll and polyphenol maintained a steady level and were positively correlated, while the oxidases tended to increase. Burley 21 contained the lowest amount of polyphenols among the chlorophyll mutants, although the low chlorophyll content of its mature leaves was comparable to that of SC58-yg. Use of cultural practices for flue-cured tobacco caused an accumulation of polyphenols in green leaves. There was a greater loss of soluble polyphenols during air-curing than during flue-curing. Results indicate that the interaction of cultural practices with chlorophyll-deficient genes affects the metabolism of chlorophylls and polyphenols during leaf growth and maturation. Introduction of these genes into tobacco cultivars may provide a means of enhancing uniformity of leaf maturity and modifying certain leaf chemical constituents.

Uneingeschränkter Zugang

Pyrolytic Evaluation of Close-Grown Tobaccos

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 65 - 72

Zusammenfassung

Abstract

A pyrolytic method for evaluating the smoke properties of tobacco materials for their potential to produce biologically significant smoke phenols and PAH has been applied to close-grown tobacco, in comparison to conventionally grown tobacco. Analyses were performed on the lipids of tobacco samples to attempt correlations with amounts of polynuclear aromatic hydrocarbons in pyrolyzates. Relative to a standard flue-cured tobacco, the close-grown tobacco samples contained lower nicotine, neophytadiene and hydrocarbon levels, and lower sterols, solanesol and fatty acid levels. Close-grown tobacco pyrolyzates contained equivalent PAH levels and higher levels of phenols. Based on the pyrolysis data, the close-grown tobaccos do not offer a more desirable smoking product than conventionally grown flue-cured tobaccos. However, the lower levels of nicotine and higher amounts of smoke phenols may possibly make the close-grown materials suitable for inclusion into low-nicotine tobacco sheet products.

Uneingeschränkter Zugang

Gas Chromatographic Determination of Pesticide Residues in Plant Material after Clean-up by Gel Chromatography and Mini-silica Gel Column Chromatography1st Report: Organochlorine Pesticides in Tobacco and Tobacco Products/Gaschromatographische Bestimmung von Rückständen an Pflanzenbehandlungsmitteln nach Clean-up über Gelchromatographie und Mini-Kieselgel-Säulenchromatographie: 1. Mitteilung: Organochlor-Pflanzenbehandlungsmittel in Tabak und Tabakerzeugnissen

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 73 - 79

Zusammenfassung

Abstract

This report contains the first description of a method for pesticide residue determination using automated gel permeation chromatographic clean-up. The example of organochlorine pesticides in tobacco and tobacco products has been taken here to illustrate this method. Water is added to the sample which is then extracted with acetone such that the ratio of the volume of acetone used to the total volume of water is 2 :1. The key step in the method is the efficient removal of co-extracted plant constituents, by gel permeation chromatography on a polystyrene gel (Bio-Beads S-X3). The pesticides are recovered, without loss, in 65 ml of eluate. This eluate is further purified by very simple chromatography on a 1 g column of deactivated silica gel, two 10 ml fractions being collected. No interfering substances are present m these fractions and the pesticides may be identified and quantified without ambiguity. The limit of detection was, for example, for α-BHC 0.002 mg/kg and for p,p'-DDT 0.02 mg/kg. The recoveries of pesticides from spiked samples lay between 90 and 100 %. The method is also suitable for the extraction and purification of polar pesticides so that with a single sample processing a large number of different pesticides may be determined by GLC. This will be described in a forthcoming paper.

10 Artikel
Uneingeschränkter Zugang

Design Criteria for Ventilated Filters

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 1 - 6

Zusammenfassung

Abstract

A number of filters were studied to determine the effect of air dilution on smoke filtration, both in well characterized acetate tow items and also in commercial filters that incorporated air dilution. A direct reduction of condensate and nicotine was observed in proportion to the degree of air dilution. Particulate filtration efficiency increased with air dilution. Gas phase delivery of aldehydes and CO decreased in greater proportion than the amount of air dilution. The commercial brands tested closely fitted the model developed in the filter tow study, except where mouthpieces or other flow channeling devices altered the filtration characteristics of the cigarette in varying degrees. Significantly, the results of the studies showed that the amount of air dilution, and not the physical means of air mixing, was the defining parameter to predict filter performance. Ventilation gives a useful design capacity that extends control of smoke filtration behaviour. By appropriate selection of tow denier per filament, total denier and cross-section shape, filter length and diameter, and the level of air dilution, filter properties can be adjusted to control gas and particulate phase deliveries, and the proportionality between the two.

Uneingeschränkter Zugang

The Use of Pressure Drop Measurements for Estimating Ventilation and Paper Porosity

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 7 - 16

Zusammenfassung

Abstract

Equations for calculating dilutions in vented cigarette filters and tobacco columns from pressure drop measurements are derived. These calculated dilutions are found to agree closely with those directly measured for a variety of commercial and experimental cigarettes wrapped with perforated and porous tipping and with different cigarette papers. The effect of hole placement on dilution and cigarette pressure is estimated. The effects of filter dilution on particulate matter, condensate and carbon monoxide delivery are discussed. A method for measuring filter dilution during smoking by means of pressure drop measurements is outlined and results for a typical vented filter cigarette are shown and discussed. The use of pressure drop measurements for estimating paper porosity and amount of dilution in the tobacco column on finished cigarettes is out-lined. The dilution obtained by this method was generally higher compared to the results found by a model based on a capillary flow regime, which suggests that flow through ordinary cigarette paper is a combination of capillary and orifice flow. The non-destructive nature and simplicity of pressure drop measurements make this method of measuring dilution useful in quality control of cigarette production.

Uneingeschränkter Zugang

Studies on the Natural Smouldering of Cigarettes: III. Determination of the Thermal Properties of Tobacco Shreds Packed in Columns

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 17 - 23

Zusammenfassung

Abstract

The values of effective thermal conductivity, specific heat and thermal diffusivity of various kinds of tobacco shreds, which are necessary for the solution of heat transfer problems of a smouldering cigarette, were determined. Effective thermal conductivity of tobacco shred packed into simulated cigarette columns was measured by a transient hot-wire method as a function of packing fraction at conditions of 20°C and 60 % relative humidity. Specific heat was measured with the aid of a differential scanning calorimeter (DSC). The thermal diffusivity was obtained from the values of effective thermal conductivity, specific heat and packing density. Effective thermal conductivity increased with increasing packing fraction (1 - e) and was uniformly expressed as a function of the total void fraction (et) inside the column regardless of tobacco types and stalk positions, whereas thermal diffusivity decreased with the packing fraction. At the same packing fraction, bright shreds produced higher values of effective thermal conductivity as well as higher specific heats (although specific heat was independent of the packing fraction) but had lower thermal diffusivity values than Burley and Matsukawa shreds.

Uneingeschränkter Zugang

A Unified Smoking-Automated Calorimetric System for the Analysis of the Gas Phase of Cigarette Smoke and its Application to the Determination of Hydrogen Sulfide

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 24 - 30

Zusammenfassung

Abstract

A system has been developed wherein the gas phase produced on smoking a cigarette through a Cambridge pad is analysed, on a puff-by-puff basis, for a desired component using automated colourimetry. The system consists of an AutoAnalyser I and a simple, 1-port smoking machine. The continuous gas stream from the smoking machine, either gas phase or intervening air, is passed concurrently with a stream of absorbing solution through a glass coil. Following passage through the coil, the solution is separated from the gas stream and introduced into the AutoAnalyser for continuous measurement of the concentration of the absorbed component. The entire system is calibrated using standard gas mixtures puffed in the same manner as the cigarette. The puff profile is essentially rectangular. Chief benefits expected from use of this system include the ability to obtain puff-by-puff measurements, a minimum time for reaction to occur in the gas phase and essentially no sample handling other than smoking the cigarette. The system has been utilized for the determination of hydrogen sulfide in gas phase using 0.1 N NaOH as the absorbing solution and the "methylene blue" colourimetric reaction. Results obtained on a variety of commercial U.S. brands ranged from 18 to 50 µg of H2S per cigarette, similar to results reported by other investigators using wet chemical methods. The accuracy of the results is supported by recovery tests wherein gaseous H2S added to the gas phase is completely recovered. The average relative standard deviations obtained with 11 U.S. commercial or reference cigarette samples using random selection of the cigarettes is 10.8 % for µg of H2S per cigarette and 8.8 % for µg of H2S per puff for a single cigarette. The basic system is thought to be applicable to the determination of a number of other components in gas phase.

Uneingeschränkter Zugang

Composition Studies on some Varieties of Tobacco and their Smoke: I. Major Components in Smoke Condensate

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 31 - 38

Zusammenfassung

Abstract

The relative proportions of the major smoke components and N-containing components in the semi-volatile phase and the non-volatile phase from some varieties of tobacco, i.e. flue-cured, Burley and Turkish tobacco, were determined. In flue-cured tobacco smoke, 2-furfural, 5-methylfurfural, 5-hydroxymethylfurfural and other carbohydrate pyrolysates, catechols and organic acids were present in higher concentrations than in the smoke from the other tobaccos. In Burley tobacco smoke, myosmine was present in much higher concentration than in the smoke from the other tobaccos. In Turkish tobacco smoke, glycerol and β-methylvaleric acid were both present in much higher concentrations.

Uneingeschränkter Zugang

Dihydro-γ-pyrones in Tobacco SmokeIdentification of 2,3-Dihydro-5-hydroxy-6-methyl-4H-one in the Smoke of Cigarettes from Burley, Virginia and Oriental Tobacco/Dihydro-γ-pyrone im Tabakrauch: Nachweis von 2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-4-on in Rauch von Cigaretten aus Burley-, Virginia- und Orienttabaken

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 39 - 47

Zusammenfassung

Abstract

2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-one [I] has been identified as a new cigarette smoke constituent. The concentration of substance I and of the homologous compound 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one [II] - determined in the smoke of Oriental, Virginia and Burley leaf - varies according to the type of tobacco. The amounts of substance I are 26, 20 and 6 µg a cigarette in the smoke of Oriental, Virginia and Burley tobaccos, respectively. For compound II the corresponding figures are 11, 13 and 4 µg a cigarette. Substance I is a new flavour compound which has a caramel odour with fruity overtones. This is undoubtedly important for the aroma of tobacco smoke. However, the presence of dihydro-γ-pyrone I in tobacco smoke is of theoretical interest as well. It is a cyclic enolone and has a structure similar to that of maltol and the cyclopentenolones, which we identified in tobacco smoke some time ago. Based on the similarity of structures we want to put forward the working hypothesis that a majority of the aroma substances in tobacco smoke have the constitution of an alicyclic or O-heterocyclic enolone containing a carbonyl and a C-alkyl (methyl or ethyl) group.

Uneingeschränkter Zugang

Some Factors Influencing Tobacco Leaf Senescence

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 48 - 56

Zusammenfassung

Abstract

Tobacco leaf disks were subjected to various types of lighting and chemical solutions to determine the interaction of these factors in leaf senescence. Far-red light promoted senescence more than light of lower wave-lengths. Magnesium at 50 mM was a potent inhibitor of senescence, whereas EDTA-disodium salt at 50 mM promoted senescence in the light but retarded senescence in the dark. Additional work with the effect of ethylene on detached leaves demonstrated that hydrolytic enzyme activity for amylase, peptidase and protease increased as a result of treatment but esterase activity decreased. The response differed with regard to variety and leaf maturity. Exposure to ethylene increased chlorogenic acid oxidase in lower leaves of pale yellow tobacco but decreased the enzyme in NC-95 lower leaves. These data relate to the growth behaviour of the two genotypes in that physiological maturity occurs at considerably different rates in pale yellow and NC-95 plants. The results help to explain why leaves of pale yellow plants tend to ripen within a much shorter time than leaves of conventional green tobacco cultivars.

Uneingeschränkter Zugang

Polyphenol Accumulation in Chlorophyll Mutants of Tobacco under Two Cultural Practices

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 57 - 64

Zusammenfassung

Abstract

Quantitative variation in plastid pigments and polyphenols during leaf growth and after curing have been studied with several chlorophyll-deficient genotypes of tobacco. Under culture for flue-cured tobacco, the chlorophyll-deficient pale-yellow (NC95-Py) and yellow-green (SC58-yg) lines did not differ in polyphenol accumulation from the corresponding normal green recurrent parents NC95 and SC58. A negative correlation was evident between concentrations of polyphenol and chlorophyll. Decrease of the latter during leaf growth was accompanied with a decline of PPO and PRO activities. When the chlorophyll-deficient genotypes were grown under conditions for Burley tobacco, concentrations of chlorophyll and polyphenol maintained a steady level and were positively correlated, while the oxidases tended to increase. Burley 21 contained the lowest amount of polyphenols among the chlorophyll mutants, although the low chlorophyll content of its mature leaves was comparable to that of SC58-yg. Use of cultural practices for flue-cured tobacco caused an accumulation of polyphenols in green leaves. There was a greater loss of soluble polyphenols during air-curing than during flue-curing. Results indicate that the interaction of cultural practices with chlorophyll-deficient genes affects the metabolism of chlorophylls and polyphenols during leaf growth and maturation. Introduction of these genes into tobacco cultivars may provide a means of enhancing uniformity of leaf maturity and modifying certain leaf chemical constituents.

Uneingeschränkter Zugang

Pyrolytic Evaluation of Close-Grown Tobaccos

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 65 - 72

Zusammenfassung

Abstract

A pyrolytic method for evaluating the smoke properties of tobacco materials for their potential to produce biologically significant smoke phenols and PAH has been applied to close-grown tobacco, in comparison to conventionally grown tobacco. Analyses were performed on the lipids of tobacco samples to attempt correlations with amounts of polynuclear aromatic hydrocarbons in pyrolyzates. Relative to a standard flue-cured tobacco, the close-grown tobacco samples contained lower nicotine, neophytadiene and hydrocarbon levels, and lower sterols, solanesol and fatty acid levels. Close-grown tobacco pyrolyzates contained equivalent PAH levels and higher levels of phenols. Based on the pyrolysis data, the close-grown tobaccos do not offer a more desirable smoking product than conventionally grown flue-cured tobaccos. However, the lower levels of nicotine and higher amounts of smoke phenols may possibly make the close-grown materials suitable for inclusion into low-nicotine tobacco sheet products.

Uneingeschränkter Zugang

Gas Chromatographic Determination of Pesticide Residues in Plant Material after Clean-up by Gel Chromatography and Mini-silica Gel Column Chromatography1st Report: Organochlorine Pesticides in Tobacco and Tobacco Products/Gaschromatographische Bestimmung von Rückständen an Pflanzenbehandlungsmitteln nach Clean-up über Gelchromatographie und Mini-Kieselgel-Säulenchromatographie: 1. Mitteilung: Organochlor-Pflanzenbehandlungsmittel in Tabak und Tabakerzeugnissen

Online veröffentlicht: 14 Aug 2014
Seitenbereich: 73 - 79

Zusammenfassung

Abstract

This report contains the first description of a method for pesticide residue determination using automated gel permeation chromatographic clean-up. The example of organochlorine pesticides in tobacco and tobacco products has been taken here to illustrate this method. Water is added to the sample which is then extracted with acetone such that the ratio of the volume of acetone used to the total volume of water is 2 :1. The key step in the method is the efficient removal of co-extracted plant constituents, by gel permeation chromatography on a polystyrene gel (Bio-Beads S-X3). The pesticides are recovered, without loss, in 65 ml of eluate. This eluate is further purified by very simple chromatography on a 1 g column of deactivated silica gel, two 10 ml fractions being collected. No interfering substances are present m these fractions and the pesticides may be identified and quantified without ambiguity. The limit of detection was, for example, for α-BHC 0.002 mg/kg and for p,p'-DDT 0.02 mg/kg. The recoveries of pesticides from spiked samples lay between 90 and 100 %. The method is also suitable for the extraction and purification of polar pesticides so that with a single sample processing a large number of different pesticides may be determined by GLC. This will be described in a forthcoming paper.

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