近岸海水中络合态铁的离心超滤粒径分级方法研究  

A study of size fraction of colloidal iron in coastal waters utilizing centrifugal ultrafiltration

作　　者：陈耀瑾[1] 袁东星[1] 黄勇明[1] 冯思超[1] 方锴[1] 

机构地区：[1]厦门大学近海海洋环境科学国家重点实验室环境与生态学院,福建厦门361102

出　　处：《海洋通报》2015年第1期83-88,共6页Marine Science Bulletin

基　　金：国家自然科学基金(41176075)

摘　　要：建立了基于离心超滤技术的近岸海水中络合态铁（Fe）粒径分级方法。经0.45μm滤膜过滤的海水样品,分别用不同孔径（3 k Da、10 k Da、30 k Da、100 k Da）的超滤膜离心超滤并脱盐。不同分子量范围的化合物富集于相应孔径的超滤膜上,以酸溶液提取出Fe,用原子吸收光谱法（GFAAS）测定。在优化的条件下,方法检测限为0.10μg·L-1,线性范围0.25-10μg·L-1,4组不同孔径超滤膜测定同一份样品的相对标准偏差（RSD）为6.4%-10.3%。本方法成功应用于福建九龙江口至厦门西海域水样的测定,结果显示各分子量范围内的络合态Fe含量随盐度增高而降低,且呈非保守分布的变化趋势。Centrifugal ultrafiltration technique has been used for size fraction of colloidal iron in coastal waters in present studies. The seawater sample, which had been filtered through the 0.45 μm membrane, was filtered and desalted by centrifugal ultrafiltration with different pore sizes of membranes（ 3 k Da, 10 k Da, 30 k Da, 100 k Da）. The colloids in different molecular weight ranges were filtrated on the corresponding membranes. Colloidal iron was extracted with acid solution and detected with graphite furnace atomic absorption spectrometry（GFAAS）. Under the optimized conditions, the detection limit was 0.10 μg·L-1, and the linear range was 0~10 μg·L-1. Using different pore sizes of membranes, the relative standard deviations（RSDs） for the same coastal water sample were in the range of 6.4 %~10.3 %（ n=4）. The proposed method had been successfully applied to analyze the samples collected from Jiulongjiang Estuary and Western Xiamen Harbour, Fujian, China. The concentrations of colloidal iron in every range of molecular weight decreased as salinity increased and the trends indicated a non-conservative mixing process in the studied area.

关 键 词：近岸海水 络合态铁 粒径分级 离心超滤 石墨炉原子吸收光谱法 

分 类 号：P734[天文地球—海洋化学]