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.