中文摘要：

通过过滤（0．7μm）和切向超滤（100kDa、10kDa、1kDa）技术将实验室内培养的赤潮异弯藻和中肋骨条藻藻液分离成100kDa-0．7／μm、10～100kDa、1～10kDa的胶体浓缩液和〈1kDa的超滤液，利用激发．发射矩阵荧光光谱技术测定了不同粒级溶液中有机物的荧光性质，分析了三维荧光光谱图中的荧光峰位置、数量及荧光强度的变化情况。结果表明，两种微藻产生的类腐殖质荧光物质主要是〈1kDa的小分子物质。赤潮异湾藻产生的类蛋白荧光物质中，15％是100kDa-0．7μm的大胶体，8％是10～100kDa的中胶体，而大部分是〈1kDa的小分子物质。赤潮异弯藻各级超滤截留液的类蛋白荧光峰的发射波长与过滤液相比，发生蓝移，而超滤液的则发生红移，表明赤潮异湾藻产生的类蛋白荧光物质随着粒径的增大极性减弱。

英文摘要：

The filtration and cross-flow ultrafihration techniques were used to isolate the culture mediums of Heterosigma akashiwo and Skeletonema costatum into the retentate of 100kDa-0.7μm, 10-100kDa and 1-10kDa and the ultrafiltrate of 〈 1kDa. The different sizes of dissolved organic matter were detected by the three-dimensional fluorescence excitation-emission matrix spectrum. The peak, peak number and intensity of fluorescence in the spectra plots were analyzed. It is showed that the humic-like fluorescence substance was mainly composed of 〈 1 kDa molecules. The 15 % of the proteinlike fluorescence substances produced by Heterosigma akashiwo were the macro-colloid of 100kDa-0.7μm, 8 % were the mid-colloid of 10-100kDa, and the most of them were the micro-molecule of 〈 lkDa. Compared to the filtrate of Heterosigma akashiwo, the emission wavelengths of protein-like fluorescence peaks in the different sizes of ultrafiltration retentate were blue-shifted, but these in the ultrafiltrate were red-shifted, which suggested that the polarity was decoupled with the size increasing of the protein-like fluorescence substances produced by Heterosigma akashiwo.