- Dettagli della rivista
- Formato
- Rivista
- eISSN
- 2719-9509
- Pubblicato per la prima volta
- 01 Jan 1992
- Periodo di pubblicazione
- 4 volte all'anno
- Lingue
- Inglese
Cerca
- Accesso libero
An Automated Procedure for the Determination of Ammonia in Tobacco
Pagine: 167 - 172
Astratto
A procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate
- Accesso libero
Method for the Rapid Determination of Acetic and Higher Acids in Cigarette Smoke
Pagine: 173 - 177
Astratto
A method for the rapid determination of acetic and higher aliphatic acids in cigarette smoke is described. Cigarette smoke is collected on a Cambridge filter, which is followed by a carbon disulfide scrubber. The total particulate matter (TPM) on the Cambridge filter is dissolved in carbon disulfide, and the acids are then extracted from this solution into an aqueous sodium borate solution (pH 8). An aliquot of this extract is injected onto a gas chromatographic column containing Chromosorb 101 column packing. The determination of acetic acid requires the smoke of 5 cigarettes and is completed in 15 min (10 min for extraction and 5 min for chromatographic separation). The coefficient of variation of the method is 3.8 %. The determination of acetic through hexanoic acid requires the smoke of 20 cigarettes and is completed in 20 min. The amounts of acetic acid delivered from cigarettes of various types were determined. Commercial cellulose acetate filters removed a slightly higher percentage of acetic acid than dry TPM from the smoke of a domestic cigarette
- Accesso libero
The Use of Cryogenic Temperature Gas Chromatography for the Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke
Pagine: 178 - 181
Astratto
A gas chromatographic method for the determination of carbon monoxide and carbon dioxide in cigarette smoke was developed. A column containing Porapak Q packing and a cryogenic temperature programmer which employed liquid nitrogen to cool the column to subambient temperatures was used. The separation of N2, O2, CO, and CO2 was accomplished at temperatures of -70°C to 40°C, and the organic vapour phase of smoke was analysed as the column temperature was programmed to 220°C. The inorganic gases were detected by thermal conductivity and the organic vapours by flame ionization. The method was used to determine the amounts of carbon monoxide and carbon dioxide in the smoke of nonfilter, filter, and vented-filter cigarettes, and to analyse the organic vapour phase of smoke
- Accesso libero
Evaluation of Acids and Phenols in the Semi-Volatile Fraction of the Smoke of Blend Cigarettes and of Cigarettes Made from Virginia, Burley and Oriental Tobaccos - Säuren und Phenole in der „Semi-Volatile“-Fraktion des Rauches von Blend-, Virginia-, Burley- und Orient-Cigaretten
Pagine: 182 - 188
Astratto
The purpose of this work was to compare the composition of the semi-volatile fraction of the smoke of different tobacco types. A German blend cigarette without any additive and further three cigarettes made from Virginia, Burley and Oriental tobaccos were compared. The composition of the acidic fraction of the "semi-volatiles" of the smoke was analysed. 22 substances including the newly identified octadeca-9,12,15-trien-1-ol were identified by GC and mass spectrometry and quantitatively determined by GC-methods. Although in general all the smoke samples were qualitatively similar in volatile acid and phenol composition, there were, quantitatively, remarkable differences between the different tobacco types. In the semi-volatile fraction of the smoke of the Oriental cigarette, the level of 3-methylvaleric acid and isovaleric acid was highly increased. The semi-volatile fraction of the smoke of the Virginia cigarette showed an overall increased level for the rest of the aliphatic acids which we analysed. Especially the amount of palmitic acid is increased. Phenol, cresol, catechol, guajacol and benzoic acid were also increased compared with the Burley and Oriental cigarettes. In the semi-volatile fraction of Burley smoke all analysed substances were diminished
- Accesso libero
Composition Studies on Tobacco: XLVI. Attempts to Modify Selected Biochemical Properties of Cigarette Smoke by the Use of Specially Treated Filters
Pagine: 189 - 193
Astratto
Aqueous solutions of cigarette smoke produced by collecting smoke in dilute buffer were monitored during puffing for alterations in redox potential and pH. These solutions were examined subsequently for their inhibitory effect on yeast alcohol dehydrogenase, their reaction with model disulfide and sulfhydryl compounds, and their reaction with the colourimetric oxidation-reduction indicator 2,6-dichlorophenol indophenol. These properties were selected to indicate possible biochemical reactions of smoke, and to distinguish between alternative theories for observed enzyme inactivation. Previous experiments had indicated that smoke constituents that react with sulfhydryls might be responsible for such behaviour and that such constituents might be removed selectively by filter agents. Cellulose cottons treated to introduce sulfhydryl and/or ion-exchange groups were employed as filter additives, and the smoke solutions were examined for alterations in their reactivity with the above tests. Sulfhydryl reactivity appears to be too slow for effective selective filtration of such reactants from tobacco smoke. The various tests are evaluated on the basis of the contribution of the two phases; the vapour phase contains the components affecting pH, aldehyde content, and reactions with disulfides, and the particulate matter phase contains the components mainly affecting the remaining tests
- Accesso libero
Comparison of the Performances of Different Types of Smoking Machines/Vergleich der Messgenauigkeit von Rauchmaschinen
Pagine: 194 - 197
Astratto
The performances of smoking machines of different types cannot be compared directly if different numbers of cigarettes are smoked into one trap, because the respective variabilities are depending on the number of cigarettes smoked into one trap. For the comparison of means, the t-test can therefore not be used directly. It is demonstrated that a generalized t-test can notwithstanding be applied to this problem in most cases, in particular when the standard deviations per cigarette are of the same order of magnitude
- Accesso libero
RM 20 - A Smoking Machine for Routine Analysis of Tobacco Smoke/Die RM 20 - eine Rauchmaschine für analytische Untersuchungen
Pagine: 198 - 204
Astratto
A smoking machine for the routine analysis of tobacco smoke is described. The machine is equipped with special controls for parameters such as puff duration interval between puffs, number of puffs, automatic interruption of the puffs at a given butt length, expulsion of the butt, control of puff volume by a soap film burette. By these devices the various conditions of machine smoking can easily be set up. At the same time up to twenty cigarettes from different samples can be smoked into separate traps (glass fibre filters). For the simultaneous smoking of twenty cigarettes into one common trap, a large glass fibre filter or an electrostatic trap can be joined. For the application of a vacuum a rotary pump (rectangular puff profile) as well as a piston pump (either rectangular or bell-shaped puff profile) can be used. The machine is suitable for both restricted and free smoking and a change between these two conditions can mechanically be achieved in a few seconds