Thermogravimetric analysis of the pyrolysis of several materials used in the preparation of commercial cigarettes

Abstract

Nowadays, smoking habit represents a serious problem for the society, with negative consequences on the health of the human and a great impact on the public health department budgets. The smoke generated from the combustion of tobacco has a series of toxic and carcinogenic compounds that are inhaled by both, active and passive smokers, and turns the tobacco consumption in one of the main death causes on a global scale. There are several complex mechanisms involved in the process of smoking tobacco. The smoke evolved is consequence of the pyrolysis, combustion and partial oxidation of the tobacco strands and additives as well as of the primary products evolved from such processes that may condense in the cold sections upstream of the tobacco rod [1]. Moreover, it is well known that the composition of the commercial cigarettes include several additives in order to modify several structural or organoleptics (flavors, humectants, binders, process aids and preservants) . In most countries, the use of such additives is regulated by the normatives applicable to alimentary additives, despite it is obvious that additives passing such regulations, may produce pyrolysis and combustion products do not passing them. Therefore, there is a general agreement in the importance of carrying out studies focused on the individual behaviour of the different cigarette ingredients in the smoking process as well as on their contribution to the global composition of the tobacco smoke [2,3]. In this work, the pyrolysis of reference tobacco and three substances widely employed as cigarette ingredients (two humectants: glycerol and sorbitol, and a flavor: sucrose), as well as the corresponding mixtures tobacco-ingredient, has been studied by thermogravimetric analysis. The results obtained have permitted to characterize the thermal behavior of each material and to obtain information related to the possible interactions between the tobacco and the ingredient. In this way, the mixtures tobacco-glycerol and tobacco-sorbitol seem to show an additive behavior, thus indicating that the pyrolysis of tobacco and the ingredient are almost independent processes. However, the pyrolysis of the sugar would be affected by the presence of tobacco. Thus, it can be concluded that not only a necessity of studying the contribution of cigarette ingredients to the global toxicity of cigarettes exists, but the possible interactions tobacco-ingredients must be considered.