抄録
Mutagenic activity was tested for 10 organic solvent-extracts of airborne particulates in order to find the extracting solvent most suitable for a routine mutagenicity survey of air pollutants. Organic matter in airborne particulates was extracted by the soxhlet extraction method. Solvent used were acetonitrile, methanol, benzene, benzene-ethanol (4: 1, v/v), acetone, ethylacetate, ethanol, cyclohexane, ethylether and n-hexane, respectively. Mutagenic activities of these extracts were measured by the pre-incubation method using Salmonella typhimurium TA100 and TA98 strains with and without S-9 mix.
The mutagenic activities of these extracts were in the following order; acetonitrile, benzene-ethanol, acetone, ethylacetate, ethanol, methanol, benzene, cyclohexane, ethylether and n-hexane. The eight solvent extracts other than ethylether and n-hexane extracts showed positive mutagenic activity for the both strains mentioned above with and without S-9 mix. The ethylether and n-hexane extracts gave negative mutagenic activity for TA98 strain in the test condition without S-9 mix, although these extracts gave positive response for the other test conditions. The mutagenic activity of the acetonitrile extract was very strong and was statistically significant for the activities of the other solvent extracts. The activities of benzene-ethanol and acetone extracts were also significantly higher than those of cyclohexane, ethylether and n-hexane extracts. However, there was no significant difference among the activities of benzene-ethanol, acetone, ethylacetate, ethanol, methanol and benzene extracts.
Stability of mutagens during the soxhlet extraction for 8 hr was also tested usingwell known 6 mutagens (benzo (a) pyrene, quinoline, 8-hydroxyquinoline, 2-aminofluorene, 2-nitrofluorene and 2-acethylaminofluorene) and organic matter extracted from airborne particulates by an ultrasonic extraction method. Mutagenic activity of 2-acethylaminofluorene decreased by the refluxing in three kinds of spectral grade solvents of acetonitrile, acetone and ethylacetate. This decrease was caused by the reaction of 2-acethylaminofluorene with impurities in these solvents. It was also proved that mutagenic activity of organic matter in airborne particulates was strongly enhanced by refluxing it in acetonitrile for 8 hr, and slightly decreased in methanol. But, benzeneethanol gave no effect on the mutagenic activities of these compounds. Benzene-ethanol has also been used as an extracting solvent in a chemical analysis of organic substances such as polynuclear aromatic hydrocarbons in airborne particulates. From these results mentioned above, it was able to be concluded that benzene-ethanol (4: 1, v/v) was the most suitable solvent for a routine mutagenic survey as well as chemical analysis of organic matter in airborne particulates.
