GENOTOXIC ACTIVITY OF 1-NITROPYRENE IN WATER FROM THE YODO-RIVER, JAPAN

The identification of mutagenic I-nitropyrene, one of the direct-actin g nitroarenes, in a source of municipal drinking water is described. A diethyl ether extract recovered from river water by the XAD-2 resin c olumn method was separated into neutral, acid and basic fractions. The neutral fraction accounted for 52 and 36%, respectively, of the genot oxicity of the extract in the absence and the presence of the metaboli c activation system, for strain NM2009, which is sensitive to nitroare nes and/or aminoarenes. When separated by silica gel column chromatogr aphy, the benzene fraction of the neutral fraction, showed the highest genotoxic activity. The genotoxicity of the benzene fraction accounte d for 80 and 60%, respectively, of the neutral fraction, in the absenc e and the presence of S9 mix. These results show that mutagenic nitroa renes might be contained in the benzene fraction of the neutral one. T he benzene fraction was further subjected to HPLC and fractionated. A 1-nitropyrene-corresponding fraction was collected and subjected to ca pillary gas chromatography-mass spectrometry (GC-MS). The mass spectru m showed molecular and fragment ion peaks of 1-nitropyrene: 247, 217, 201, 189. Moreover, the concentration of 1-nitropyrene in municipal ri ver water was 1 ng/l, accounting for only 1% of the total genotoxicity .