Selective Adsorption of Nitrate and Nitrite from Tobacco Leaf Homogenates

A procedure has been developed for the reduction of nitrate / nitrite in tobacco during the homogenized leaf curing process. This procedure involves the precipitation of these anions with a polymer composed of the nitron 1,4-diphenyl-3,5-endoanilino-4,5-dihydro-1,2,4-triazole linked to poly(vinylbenzyl chloride). This poly(vinylbenzyl-nitron chloride) complex was coated onto several inert supporting materials and tested for anion binding capacity using nitrate/nitrite standards and tobacco leaf extracts. When coated onto the surface of acid-washed sand, the nitron polymer was capable of repeated regeneration with no detectable loss of nitrate / nitrite binding capacity. The nitron polymer had a slightly greater affinity for nitrite than for nitrate; however, due to the high ratio of nitrate to nitrite in tobacco leaf tissues, nitrate was the principle anion adsorbed from leaf homogenates. Large scale application of this selective nitrate adsorbing polymer during homogenized leaf curing of tobacco could significantly reduce these potentially harmful components in smoking products.