Identification and Characteristics of Organic Compounds in Tap Water Trapped by Membrane of Microporous Polyethylene Hollow Fibers.

Abstract

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.