厦门内湾沉积物中新沉积硅藻来源生物硅分离测定方法的初步研究  

A Methodological Study on the Determination of Biogenic Silica Sourced from Newly Sedimentated Diatom in Xiamen Inner-bay Sediment

作　　者：刘芳[1] 赵立波[1] 黄凌风[1] 郭丰[1] 

机构地区：[1]厦门大学海洋学系,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2008年第2期294-299,共6页Journal of Xiamen University：Natural Science

基　　金：福建省自然科学基金(B0110003)资助

摘　　要：生物硅是指生源无定形硅,它作为表层初级生产力及水体环境历史的良好指标,被广泛地应用于古海洋学过程和古气候历史的追溯研究.硅藻是生物硅的主要来源,分离测定沉积物中硅藻来源的生物硅,能更直接地将沉积物中生物硅含量与表层初级生产力联系起来.本研究通过不同种类和浓度的碱性提取液对硅藻、纯SiO2、硅藻土、海绵骨针进行Si的连续提取实验,并对实验结果进行对比分析,建立了一套将沉积物中新沉积硅藻来源的生物硅从总生物硅中分离提取的方法:向经过预处理的15 mg沉积物样品中加入10 mL 0.5 mol/L Na2CO3溶液,振荡混匀后,放入90℃恒温水浴中提取1 h,提取的生物硅基本为沉积物中新沉积硅藻来源的生物硅,并对该方法的可行性和精确度进行了检验.应用该方法对厦门内湾表层沉积物样品进行了测定和方法验证,并推算出该海域沉积物中新沉积硅藻来源生物硅的年溶出比例约为5.67%.Biogenic Silica （BSi）, as a good indicator of pelagic primary productivity and ambient history, has been widely used as a proxy of paleooceanography events and paleoclimate. Diatom is a major source of BSi, and diatom-sourced BSi is regarded directly con-necting to primary production. In this study,different kinds and concentrations of extracting solution were used to test and compare the extractive efficiency of Si from diatom, SiO2, diatomite, sponge spicula. Consequently, a method was established to determine the newly sedimentated diatom-sourced BSi in the sediment samples. In this method, 10 mL of 0.5 mol/L Na2 CO3 ,as extracting solution, was added to the 15 mg pretreated sediment sample,and then the sample was digested for 1 h at 90℃ water bath. By this means,the extracted BSi maybe regarded as newly sedimentated diatom-sourced BSi in the sediment samples. The feasibility and precision of the method was studied. The sediment samples from Xiamen inner-bay were determined by the proposed method. It demonstrates that the newly sedimentated diatom-sourced BSi can be extracted sufficiently and its dissolution proportion is about 5.67 % yearly.

关 键 词：生物硅 新沉积硅藻 内湾沉积物 测定方法 

分 类 号：P593[天文地球—地球化学]