摘要：Organic compounds in tap water trapped by microporous polyethylene hollow fiber (EHF) membrane were investigated. Samples of tap water (15 or 30 m3) obtained from Katsushika-ku (Tokyo), Shinjuku-ku (Tokyo), Osaka-shi and Shizuoka-shi were passed through EHF membrane cartridges. The cartridge was then washed with 3 l of methanol, each methanol extract was concentrated and a sticky dark brown material was obtained. Weight levels of the materials except that of Shizuoka-shi were similar (3000 mg) in spite of difference in the volume of water passed. Though the percentages of total organic carbons in the extracts except that of Shizuoka-shi ranged from 14 to 19% in 15 m3 of tap water and from 23 to 29% in 30 m3 of tap water. The mutagenic activity of the extracts to Salmonella typhimurium TA98 and TA100 without S9 was highest in the Osaka-shi tap water. Fractions from this extract with a Sep-Pak Silica cartridge were analyzed by gas chromatography/mass spectrometry (GC/MS). The eluates with CH2Cl2, which contained more than 100 organic compounds, were again fractionated with a Sep-Pak Florisil cartridge and by silica-gel thin layer chromatography. Three halogen compounds were identified as oxadiazon, butachlor and its chloro analogue. Oxadiazon and butachlor in the fractions were quantified by GC/MS in selected ion monitoring mode to be 2.18 and 1.58 ppt in the Osaka-shi tap water, respectively.
