Chemical Studies on Tobacco Smoke: V. Quantitative Determination of Chlorinated Hydrocarbon Insecticides in Cigarette Tobacco and its Smoke

An analytical method was developed for the qualitative and quantitative determination of chlorinated hydrocarbon insecticides in tobacco products. It is based on three consecutive distributions, followed by column chromatography on deactivated alumina. This procedure leads to a degree of enrichment which allows the direct assessment of the insecticides by gas chromatography. For the isolation and identification of the individual components the column chromatography endfractions are separated by gas chromatography and collected from the effluent of the column. These materials are used for mass spectrometric analyses. For the quantitative analyses DDT-C14 is used as internal standard and the amount of insecticides is determined with the aid of a gas chromatograph with electron capture detector. In 1.0 g cigarette tobacco were found 11.7 µg 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane [DDD]; 4.8 µg 1,1-dichloro2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane [o,p-DDD]; 1,1 µg 1-chloro-2,2-bis(p-chlorophenyl)ethylene [DDM]; 7.8 µg 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane [DDT] and 3.6 µg of an admixture of 1,1,1-trichloro-2-(o-chlorophenyl)2-(p-chlorophenyl)ethane [o,p-DDT] and 1,1-dichloro-2-(m-chlorophenyl)2-(p-chlorophenyl)ethane [m,p-DDD]. The mainstream smoke of an 85 mm U.S. blended cigarette without filter tip contained 1.75 µg DDD, 0.45 µg o,p-DDD, 0.81 µg DDM, 0.77 µg DDT, 0.70 µg o,p-DDT plus m,p-DDD, 0.21 µg 1,1-dichloro-2-2bis(p-chlorophenyl)ethylene and 1.52 µg trans-4,4'-dichlorostilbene. Endrin was detected neither in cigarette smoke nor in U.S. tobaccos of Winter 1967-68. The transfer rates for unchanged chlorinated insecticides from cigarette tobacco into mainstream smoke amounted to 18 % for DDD, 11.6 % for o,p-DDD and 12.4 % for DDT. The findings of this study are compared with earlier publications and are briefly discussed in respect to formation of some of the chlorinated aromatic hydrocarbons and the possible, though rather unlikely, contribution of chlorinated hydrocarbon insecticides to experimental tobacco carcinogenesis.