|Budget Amount *help
¥5,600,000 (Direct Cost : ¥5,600,000)
Fiscal Year 1995 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1994 : ¥5,000,000 (Direct Cost : ¥5,000,000)
(1) Both the nitroarene analyzer and the Ames test are necessary in the study on mutagenic nitroarenes. For the simultaneous use of these two methods, several solvent systems were tested to extract 1,3-dinitropyrene (1,3-DNP), 1,6-DNP,1,8-DNP and 1-nitropyrene (1-NP) as well as directacting mutagenic activity from airborne particulates. Benzene-ethanol, acetonitrile, ethanol and methanol gave the high efficiencies. Considering toxicities, ethanol seemed to be the best solvent.
(2) Although the nitroarene analyzer determined trace levels of 1,3-, 1,6-and 1,8-DNPs and 1-NP in extracts from a few mg of airborne particulates, the reduction of nitroarenes to corresponding aminoarenes was required before injection. To remove this tedious treatment, a reducer column packed with zinc/glass beads was on-line introduced into the system. Considering the better resolution of aminoarenes, both the reducer column and a switching valve equipped with a heart-cutting loop were introduced just before the
ODS separation column. This system could determine the above four compounds in extracts from airborne particulatates without pre-column reduction.
(3) In the method, not only nitroarenes but also polycyclic aromatic hydrocarbons (PAHs) were quantitatively extracted from airborne partculates. To determine them simultaneously, both the nitroarene analyzer and a conventional high-performance liquid chromatograph with a fluorescence detector were combined using a switching valve. After the reduced sample solution was injected, four nitroarenes and eight PAHs were separately determined in the two different lines in 1h with high sensitivities.
(4) Several mutagenic nitroarenes such as 2-, 4-NPs, 2-nitrofluoranthene and 6-nitrochrycene were formed in air in the presence of NOx. To determine these compounds, a reducer column packed with zinc/glass beads and two ODS columns, one for the clean-up and the other for the concentration, were introduced into the nitroarene analyzer. By the system, the above four compounds were detected in air. The fact that their ratios to 1,3-, 1,6-, 1,8-DNPs and 1-NP in rural air were larger than those in urban air suggested the formation of those compounds during the transportation. However, their mutagenic contributions were not large. Less