Preparation of aquatic fulvic acid standard sample and preparation of those guarantee data

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"Humic substances" which exist in natural water are high molecular compounds chemically synthesized from degradation products of the plankton remains and organisms. Recently, the environmental pollution by hazardous organic compounds has been indicated. In aqueous environment, these noxious organic substances adsorb, distribute and are solubilized to the humic substances. It is important to examine the interaction between noxious organic substance and humic substances in order to study the dynamics of noxious organic substance in the environment. However, it is known that chemical property of humic substances in aqueous environment completely differ from all purchased humic substances, since it was extracted from the peat. As a representative aqueous environmental sample of Japan, Lake Biwa lake water was chosen, and aquatic fulvic acid standard sample was prepared at Kita-Komatsu lake shore station of the environmental standard point of Lake Biwa. The automatic concentration system fo … More r aquatic humic substances which consisted of giant column (φ50 cm, 20 Kg of DAX-8 resin), 3 kind connection filter columns (10,1.0,0.45μm), acid mixing column, and diaphragm pump was constructed. The pH of lake water was prepared under 2 with the automatic injection of hydrochloric acid into the filtered lake water. The humic substances were adsorbed on DAX-8 resin column by the elution of the lake water. We dealt with the lake water of about 300 tons in the period from middle October to early November 2001 and in the period from middle April to early May 2002. DAX8 resin which adsorbed the humic substances was brought back in the laboratory, the alkaline elution was done, the humic substance was recovered, and the fulvic acid was separated from humic acid as pH 1.2. By repeating and dissolving process which adsorbed to the small column again, the fulvic acid was refined, and Lake Biwa fulvic acid standard sample (2001 Autumn sample about 18 g, 2002 Spring sample : about 15 g) was obtained. Elemental analysis, functional group analysis (carboxyl group, phenolic group, carbonyl group, total hydroxyl group), ^<13>C-NMR and ^1H-NMR measurements, acid-base titration, molecular weight distribution measurement (HP-SEC), thermal decomposition mass spectrometric analysis, fluorescence analysis were carried out on the aquatic standard samples. Less