Published Online: 28 May 2014 Page range: 311 - 319
Abstract
Abstract
Cigarette smoke condensate which had been obtained by special methods was examined by means of the analytical method that transforms N-nitroso compounds into 5-nitro-2-hydroxy-benzal-derivatives in order to ascertain whether the said group of substances is formed.
Published Online: 28 May 2014 Page range: 321 - 332
Abstract
Abstract
A method for the determination of the steam-volatile non-pyridinic bases content of tobacco is described.
140 varieties of tobacco were examined. Burley tobaccos were found to contain 0.35 to 1.36 per cent of nitrogen in the form of low-boiling volatile amines. Oriental tobaccos contained 0.20 to 0.55 per cent and Virginia tobaccos of different origin contained 0.15 to 0.35 per cent. Methods of controlling the content of volatile bases in tobacco are discussed.
Published Online: 28 May 2014 Page range: 333 - 344
Abstract
Abstract
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.
Published Online: 28 May 2014 Page range: 345 - 359
Abstract
Abstract
The capacity of the six isomeric dimethylphenols to act as reagent for the quantitative determination of nitrate is examined. Only 3,4-dimethylphenol proved to be suitable for the distillation method which was found to be most appropriate to tobacco. Chromatographic and spectrophotometric investigations showed that the resultant reaction products from tobacco extracts are identical with the nitro-dimethylphenols originating from pure nitrate.
The determination of tobacco nitrate by the described method is reproducible with a coefficient of variation of about 0.9 to 1.3 per cent. The results obtained by different laboratories coincided satisfactorily. Quantities of 0.1 per cent of nitrate can be determined without difficulties.
The nitrate content depends strongly on the respective variety of cured tobacco leaf and varies from 0 to 6 per cent. Dark tobaccos are particularly rich in nitrate. Nitrate is mainly found in the ribs of tobacco leaves and in the lower leaves of the tobacco plant. The maximum quantity of nitrite contained in tobacco amounts to 0.01 per cent.
Published Online: 28 May 2014 Page range: 361 - 369
Abstract
Abstract
The influence of tobacco moisture on the content of condensate, nicotine, and total phenols in the side stream smoke of a plain cigarette was studied.
More condensate is formed from burned tobacco during the puff intervals than during the puffs themselves. With increasing moisture content the concentrations of nicotine and phenols rise in the side stream condensate and decrease in the mainstream condensate.
This effect disappears by extrapolation to the moisture content zero.
The total quantity of regained nicotine decreases with increasing moisture content. The formation of phenols decreases with increasing moisture content by about 20 per cent.
Cigarette smoke condensate which had been obtained by special methods was examined by means of the analytical method that transforms N-nitroso compounds into 5-nitro-2-hydroxy-benzal-derivatives in order to ascertain whether the said group of substances is formed.
A method for the determination of the steam-volatile non-pyridinic bases content of tobacco is described.
140 varieties of tobacco were examined. Burley tobaccos were found to contain 0.35 to 1.36 per cent of nitrogen in the form of low-boiling volatile amines. Oriental tobaccos contained 0.20 to 0.55 per cent and Virginia tobaccos of different origin contained 0.15 to 0.35 per cent. Methods of controlling the content of volatile bases in tobacco are discussed.
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.
The capacity of the six isomeric dimethylphenols to act as reagent for the quantitative determination of nitrate is examined. Only 3,4-dimethylphenol proved to be suitable for the distillation method which was found to be most appropriate to tobacco. Chromatographic and spectrophotometric investigations showed that the resultant reaction products from tobacco extracts are identical with the nitro-dimethylphenols originating from pure nitrate.
The determination of tobacco nitrate by the described method is reproducible with a coefficient of variation of about 0.9 to 1.3 per cent. The results obtained by different laboratories coincided satisfactorily. Quantities of 0.1 per cent of nitrate can be determined without difficulties.
The nitrate content depends strongly on the respective variety of cured tobacco leaf and varies from 0 to 6 per cent. Dark tobaccos are particularly rich in nitrate. Nitrate is mainly found in the ribs of tobacco leaves and in the lower leaves of the tobacco plant. The maximum quantity of nitrite contained in tobacco amounts to 0.01 per cent.
The influence of tobacco moisture on the content of condensate, nicotine, and total phenols in the side stream smoke of a plain cigarette was studied.
More condensate is formed from burned tobacco during the puff intervals than during the puffs themselves. With increasing moisture content the concentrations of nicotine and phenols rise in the side stream condensate and decrease in the mainstream condensate.
This effect disappears by extrapolation to the moisture content zero.
The total quantity of regained nicotine decreases with increasing moisture content. The formation of phenols decreases with increasing moisture content by about 20 per cent.