Systematic studies on the breakdown of p,p'-DDT in tobacco smokes.  Presence of methyl chloride, dichloromethane, and chloroform in tobacco smokes

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.

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“…the identification and estimation of the volatile degradation products of p,p'-DDT in p,p'-DDT-treated tobacco smoke • (6).…”

mentioning

confidence: 99%

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

Chopra¹,

Thekkekandam²

1973

Beiträge Zur Tabakforschung / Contributions to Tobacco Research

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“…The trichloromethyl group so formed could breakaway from the rest of the molecule to give a CC13 free radical, which in turn could react with atomic hydrogen to give chloroform (cf. Chopra and Sherman, 1972). We smoked tobacco containing 570 ppm endosulfan I but were unable to detect any chloroform (Chopra and Campbell, 1977), although we were able to detect chloroform in 2.4 ppm p,p'-DDT treated tobacco smoke (Chopra and Sherman, 1972).…”

Section: Discussionmentioning

confidence: 80%

“…These reasons also preclude the formation of the other chlorohydrocarbons unless there is an alternate route available for their formations. Methyl chloride is formed in large quantities in tobacco smoke by the action of methyl free radicals with inorganic chlorine (Chopra and Sherman, 1972).…”

Section: Discussionmentioning

confidence: 99%

Systematic studies on the breakdown of endosulfan in tobacco smokes: isolation and identification of the degradation products from the pyrolysis of endosulfan I in a nitrogen atmosphere

Chopra¹,

Campbell²,

Hurley³

1978

J. Agric. Food Chem.

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With the objective of studying the possible degradation products of endosulfan in endosulfan-treated tobacco smoke, endosulfan I was pyrolyzed at 880-900 "C. Among the pyrolysate endosulfan I and 11, endosulfan ether, hexachlorocyclopentadiene, all chlorobenzenes, methyl chloride, dichloromethane, chloroform, carbon tetrachloride, 1,l-dichloroethylene, 1,l-dichloroethane, trichloroethylene, and tetrachloroethylene were identified. From the reaction mechanisms involved in the formation of these compounds it is postulated that the endosulfan degradation products, which have a mathematical chance of being present in tobacco and cigarette smokes, are: endosulfan I and 11, endosulfan sulfate, endosulfan ether, endosulfan lactone, mono-, di-, tri-, and tetrachlorbenzenes, and hexachlorocyclopentadiene. This is our third paper on our investigations into the fate of endosulfan in tobacco and in cigarette smoke. In our earlier publications we had described the fate of endosulfan

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“…27). Similarly, when DDT (2,2-bis (pchlorophenyl)-l,l,l-trichloroethane) is present in the refuse, the cleavage of C-C bond of the ethyl group on DDT can occur to yield trichloromethyl radicals (CC1 3 ), 193 which in the reducing atmosphere produce chloroform (CHC1 3 ). 193 It is also known that the thermolysis of chloroform exhibits reversible formation of dichlorocarbene (CC1 2 ) and HC1 (Scheme 1; Reaction 40).…”

mentioning

confidence: 99%

“…Similarly, when DDT (2,2-bis (pchlorophenyl)-l,l,l-trichloroethane) is present in the refuse, the cleavage of C-C bond of the ethyl group on DDT can occur to yield trichloromethyl radicals (CC1 3 ), 193 which in the reducing atmosphere produce chloroform (CHC1 3 ). 193 It is also known that the thermolysis of chloroform exhibits reversible formation of dichlorocarbene (CC1 2 ) and HC1 (Scheme 1; Reaction 40). The carbenes may dimerize; thereby producing perchloroethylene (Scheme 1, 6), which after following a sequence of reactions and via the intermediacy of dichloroacetylene (not shown in the present Figure) provide hexachlorobenzene (Scheme 5; Figure 3).…”

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confidence: 99%

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

Choudhry

Hutzinger

1982

Toxicological & Environmental Chemistry

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The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I-IV , are also described in this paper.

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Systematic studies on the breakdown of p,p'-DDT in tobacco smokes. Presence of methyl chloride, dichloromethane, and chloroform in tobacco smokes

Cited by 18 publications

References 3 publications

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

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

Systematic studies on the breakdown of endosulfan in tobacco smokes: isolation and identification of the degradation products from the pyrolysis of endosulfan I in a nitrogen atmosphere

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

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