摘要：Trace neutral organic substances in raw sewage (influent) and secondary effluent (effluent) were investigated to reveal the fate of organic substances in the environment by gas chromatography-mass spectrometry (GC-MS) technique. Water samples (influent : 5 l ; effluent : 50 l) were separated into the filtrate and unfilterable matter through a Teflon filter having 1 μm pore size, under added pressure (1-3.2 kg/cm2). Organic substances in unfilterable matter were extracted with benzene-ethanol (1 : 1) in a Soxhlet extractor for 24 hr. The filtrate was passed through a column (1.5×12 cm) of Amberlite XAD-2 resin (20-50 mesh) and organic substances adsorbed on the column was eluted with 150 ml of ether. The ether extract was concentrated to below 1 ml in a Kuderna-Danish evaporator. The concentrate loaded on the top of a silica-gel (100-200 mesh) column (1×20 cm), was fractionated in turn with 20 ml of isooctane, 25 ml of isooctane-benzene (1 : 1), and 15 ml of benzene-methanol (1 : 1). Determination of normal alkanes (C18-C33) and polycyclic aromatic hydrocarbons (biphenyl, acenaphthene, 2, 3-dimethylnaphthalene, fluorene, phenanthrene, pyrene, benzo [a] fluorene, anthracene, benzo [b] fluoranthene, and benzo [a] pyrene), which were respectively present in the isooctane and isooctane-benzene fractions, were performed by mass fragmentography. A number of polar organic substances, including plasticizers (dialkyl phthalates, dialkyl adipates, and dialkyl carbonates) and sterols (coprostanol, cholesterol, campesterol, and sitosterol) were found in benzene-methanol fractions by a computerized GC-MS system.
