A Mechanistic Study on the Formation of the Non-Volatile Degradation Products of p,p’-DDT and p,p’-TDE in p,p’-DDT- and p,p’-TDE-Treated Tobacco Smoke

Tobacco samples containing 20 ppm p,p’-DDT, 200 ppm p,p’-DDT, 20 ppm p,p’-TDE and 200 ppm p,p’-TDE were smoked and their smoke condensates analysed for the p,p’-DDT and p,p’-TDE degradation products such as p,p’-DDT, p,p’-TDE, p,p’-DDE, p,p’-DDM, trans-dichlorostilbene, bis-(p-chlorophenyl)methane, and p,p’-dichlorobenzophenone. The degradation patterns and the amounts in which these degradation products were present in smoke condensates showed that 1. during the smoking process the more volatile compound has a better chance of not being destroyed; 2. the higher the amount of pesticide present in tobacco, the greater is the percentage loss of pesticide on smoking; 3. smoking being a pyrolytic reaction of a very short duration, “primary”, “secondary”, and “tertiary” reactions take place in the order given; 4. reactions, which have lesser energy requirements, occur more readily than those which have a higher requirement; 5. in the case of p,p’-TDE-treated tobacco smoke, some p,p’-DDE is also formed by the dehydrogenation of p,p’-TDE.