Many complaints have been made about bad smelling and tasting food and accidents resulting in the death of animals in Nagano Prefecture. The method of headspace SPME-GC/MS has been found very effective as a screening method to investigate the cause of these complaints and accidents. This method is characterized mainly in that the operation is simple without using any solvents for extraction, causing no environmental pollution; the extraction may be carried out in a short time with a small quantity of sample in low concentration, preventing reagent contamination, the whole extract may be injected, leading to high sensitivity, and the fiber may be used repeatedly, making the analytical cost inexpensive. This paper describes representative examples of cases in which the relevant causes have been solved.

A method by GC/MS has been established for the determination of Etoxazole in agricaltural products. Etoxazole was decomposed by acid contained in citrus fruits, but this decomposition could be prevented by addition of sodium acetate solution and extraction above pH 4. In the present method, the Etoxazole in agricultural products was extracted with acetone above pH 4, concentrated, and reextracted with n-hexane. After partition with acetonitrile followed by chromatographic clean-up with Florisil, the sample was subjected to GC/MS. The present method is excellent in sensitivity and has a detection limit of 0.002 micro g/g, and thus is about 10 times as sensitive as that of GC-NPD. The recovery by the present method is over 85% except for tea, the C.V. of recovery is less than 8%, and the method is applicable to actual samples.

This study investigated the distribution of organic matters in airborne aerosols. Field observations were made at Takasaki and Karuizawa, which are located along the route of the long-range transport of photochemical air pollution in summer, in two urban areas (Okaya and Nagano) in late autumn and early winter, in a rural area (Nakano) in late autumn and in a mountainous area (Happo) in autumn. Organic matter in airborne aerosol was collected on a quartz fiber filter using a high-volume air sampler for 3 days to a week. Organic compounds collected on the filter were extracted with dichlorometane and subsequently with methanol, and the extracts were subjected to GC/FID and GC/MS analyses. Pinonaldehyde, C17-C33 n-alkanes, C12-C26 fatty acids, dicarboxylic acids, phthalic acids, benzoic acid, lower molecular unresolved mixtures (LUCM) and higher molecular unresolved mixtures (HUCM) were detected in the airborne aerosols. The total concentrations of the analyzed matter accounted for approximately 20% of the organic carbon (OC) in any of the samples. Pinonaldehyde, dicarboxylic acids and phthalic acids, which are produced by photochemical reaction in the atmosphere, were more abundant in summer. Concentrations of long-chain fatty acids and UCM (LUCM + HUCM) increased in rural Nakano in late autumn, probably due to the vegetative burning of asparagus fields nearby. A large part of the analyzed matter was made up of anthropogenic compounds (n-alkanes, dicarboxylic acids, phthalic acids, benzoic acid and UCM), while biogenic ones (pinonaldehyde, n-alkanes and fatty acids) were minor contributors to the airborne aerosols. In the mountainous area, pinonaldehyde, oxalic acid and LUCM were considered to be produced by photochemical reactions during transport to Happo.