Neutron Activation Analysis in Tobacco and Cigarette Smoke Studies: The Halogens

Abstract

The mass balance for chlorine and bromine in the burning 1R1 Kentucky reference cigarette has been determined using neutron activation analyses. Gas radiochromatography has been used to measure dynamically the amounts of gamma-emitting isotopes as they elute from a gas chromatograph. The sidestream and mainstream gas phases which elute from a gas chromatograph appear to be qualitatively identical in their organohalogens, differing only in their quantitative values. The results show that a substantial conversion of ionic halides to organohalogens takes place during smoke formation and this transformation has a threshold temperature below that established during either the puffing or static burn modes of the cigarette. The chemical nature of the halogens present in the mainstream particulate smoke was 10.8 % organochlorine, 88.6 % ionic chloride, 13.3 % organobromine and 86.0 % ionic bromide

A Review of the Uses of Nuclear Radiation in Tobacco and Smoke Research

“…They studied the organohalogen composition of the gas phases and found them qualitatively identical, but quantitatively different. A significant conclusion of ]ENKINS et al (81) was that, since both gas phases were qualitatively identical, the smoke-formation mechanisms taking place for the conversion of ionic to covalent bonds for the halo-gens have threshold energies below the minimum temperatures that take place during puffing or in the staticburn mode. There are only a few reports on the use of instrumental neutron-activation analysis as an analytical research tool to study reaction mechanisms.…”

“…A material balance for the total Cl was not obtained. In a later paper, ]ENKINS et al (81) have presented mass bal-. ances for Na, K, Mn, Cl and Br in smoke from neutron-irradiated 1R1 cigarettes (Table 11).…”

“…These studies have demonstrated significant conversion of ionic halogens to organohalogens. The ionic and organohalogen content of the mainstream-smoke total particulate matter has also been investigated by }ENKINS et al (81 ). A method for studying the inorganic-Chemical composition of various fractions of mainstream smoke separated according to particle size has been described by }ENKINS (41) and was reviewed earlier in this paper.…”

“…SHRAHAN (59) described a methOd where the incoming air into a chamber holding a smoking cigarette was labelled with krypton-81m. This labelling technique had the advantage in that 81 "'Kr is a gamma emitter (E,.= 190 keV) and can therefore be monitored at greater distances between the sample and the detector as may be necessary in some experiments. The half-life of 81 "'Kr is 13 seconds which for most scientists is a disadvantage so great as to offer no advantages over the use of 41 Arlabelled air.…”

Determination of Bromide, Chloride, and Fluoride in Cigarette Tobacco by Ion Chromatography after Microwave-Induced Combustion

“…In the mainstream gas phase of cigarette smoke a minimum of six organochlorine compounds and seven organobromine compounds were present. The two major components present in the mainstream gas phase were methyl chloride and methyl bromide (Jenkins et al 1982). Methyl chloride and bromide were classified in group 3 of the International Agency for Research on Cancer (IARC), that is, there is inadequate evidence for the carcinogenicity to humans and experimental animals for these compounds.…”