中文摘要：

对东海陆架泥质沉积区两个代表性站位表层沉积物开展了黏土粒级分离提取，并对其依次进行溶剂萃取、碱解和酸解处理，得到结合程度不同的三种脂肪酸组分：有机溶剂抽提的游离态脂肪酸、碱解得到的碱解酸和酸解得到的酸解酸。三种赋存态酸的存在表明它们所联结的宏观分子的结构不同或所吸附黏土矿物的保护作用不同。不同赋存态酸的数量、组成和分布有一定差异，两站位相同赋存态酸的数量与组成也存在明显差异。组成与分布特征表明东海陆架泥质区超细颗粒物中脂肪酸以海洋内源藻类来源为主（〉70％），陆源高等植物贡献相对较低，并有少量的细菌源贡献。各赋存态酸的降解程度为碱解酸高于酸解酸高于游离酸，可能与其在黏土中的赋存状态和吸附过程有关。靠近长江河口的表层沉积物样品（24站）海洋内源藻类贡献略低于远离河口的站位（30站），陆源高等植物的输入稍高于后者，是受两泥质区沉积环境综合影响的结果。

英文摘要：

Clay size fractions were separated from two representative surface sediments of mud areas of the East China Sea shelf and subjected to sequential treatments in order to obtain quantitative and qualitative information on carboxylic acid moieties. The acid moieties occurring in each sample included： （i） the free acids directly extracted by organic solvent, （ii） the OH -labile acids released by saponification and （iii） the H＋-labile acids obtained via acid hydrolysis. Considerable differences were observed, for a given sample, depending on the particular pool, and large differences were also found between the two samples from the same pool. Composition and distribution characteristics indicated that the acid moieties were mainly derived from autochthonous microalgae （〉70%）, followed by allochthonous higher plant, and a few bacterial contributions. With respect to the degradation level of the acid moieties, the order was OH -labile 〉 H＋-labile 〉 free acid, which was related with the occurrence of acids in clay and the adsorption of clay minerals. Microalgae contribution in the surface samplesnear the Yangtzi river estuarine （station 24） is lower than that in the sample far away from estuarine （station 30）, resulting from different depositional environments in the two mud areas.