CHEMICAL AND GEOCHEMICAL STUDIES ON ORGANIC MATTER IN THE OCEAN

本工作旨在建立测定海水中溶解有机碳的分析方法，并对多种联用色质联用技术分离出的有机物的化学性质和结构进行表征。采用高温催化氧化法(HTCO-OC)和经典湿式氧化法(WO-OC)对东海陆架、陆架斜坡区和黑潮海域的海水中溶解有机碳进行分析。WO-OC/HTCO-OC因地区而异。为解决这一问题，在加拿大萨尼奇湾进行了中尺度浮游植物产生溶解有机物的实验。在中游系统中，添加营养物以引起浮游植物水华，其中溶解有机碳浓度与其他化学和物理参数一起被跟踪数周。我们清楚地发现，浮游植物在其繁殖过程中产生了由脂肪、氨基酸、蛋白质和碳水化合物组成的溶解的有机物质。用气相色谱-质谱仪、核磁共振、气相色谱-燃烧-同位素质谱仪等多种分析方法对浮游植物渗出的有机物质进行了充分的化学表征。获得的这些数据现在部分已被几个期刊提交，但其中大多数现在正在为出版做准备。

Aims of this work are to establish analytical method of determining dissolved organic carbon in the seawater and to characterize chemical nature and structure of the organic materials which were separated by variuose kinds of combined chromatography and mass spectrometry.Sea water samples collected from the East Chine Sea including the continental shelf and shelf slope areas and Kuroshio area were analyzed for dissolved organic carbon by high temperatrure catalytic oxidation (HTCO-OC) and classical wet oxidation (WO-OC). WO-OC/HTCO-OC was characteristically different from areas to areas. High values were obtained in the Kuroshio areas, while low values in the continental areas of the East China Sea, indicating that phytoplankton bloom might be playing an important role for the production of dissolved organic matter in the surface of the ocean.To solve this problems, production of dissolved organic materials by phytoplankton was pursued in the mesocosm experiment, which was conducted in the Saanich Inlet, Canada. To the mesocosm, nutients were added to cause phytoplankton bloom, in which dissolved organic carbon concentration was pursued for several weeks together with other chemical and physical parameters. We clearly found that phytoplankton produced dissolved organic matrials consisting of lipid, amino acids and proteins and carbohydrates during the course of its bloom. These organic materials exuded by phytoplankton were fully characterized chemically by variouse analytical methiods such as combined gas chromatography and mass spectrometry, nuclear magnetic resonance and gas chromatography-combusion-isotope mass spectrometry. These data obtained are now partly already submited by several journals but most of them are now under preparation for the publication.