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This paper investigated the components, especially aldehydes, in the fume condensates from four kinds of cooking oil using ultraviolet (UV) spectrometry and gas chromatography-mass spectrometry (GC-MS). It was observed that there was a great change of the UV absorption spectra from the results of the unheated oil to the results of the fume after heat treatment (190-200, 230-240, and 270-280 degrees C). There was a strong peak within the wavelength range of 260-270 nm in each condensate sample. From the GC-MS results, it was tentatively deduced that there were some 2,4-dialkylenaldehydes and other conjugated compounds in the condensates. The results showed there were large amounts of hexanal and 2-heptenal in the cooking oil fume and that the total aldehyde peak areas of the condensates from four kinds of oil were around 30-50% of the total peak area at 270-280 degrees C.

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Ozonation by-products were analyzed for two surface water sources in Southern California-Los Angeles Aqueduct Water (LAAW) and State Project Water (SPW). Included are data obtained when LAAW was being treated at the Los Angeles Aqueduct Filtration Plant and similar data obtained during a two-day experiment in which the plant was treating SPW. Some batch-scale ozonation studies are also reported. Ozonation by-products were monitored using three methods: closed-loop stripping analysis, nonionic resin accumulation, and a direct aqueous derivatization method for low-molecular-weight aldehydes, each followed by gas chromatography-mass spectrometry analysis of the extracts. The major neutral by-products appear to be aliphatic aldehydes, but the levels are unexpectedly low in SPW compared with LAAW treated under similar conditions. Low levels of several other compounds were found in ozonated water, including bromoform and some compounds tentatively identified as ketones.JOURNAL AWWA