An ultraclean cross-flow ultrafiltration technique for the study of trace metal phase speciation in seawater
An ultraclean cross-flow ultrafiltration technique for the study of trace metal phase speciation in seawater
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DOI：
10.1016/s0304-4203(96)00052-7
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发表时间：
1996-11
期刊：
影响因子：
3
通讯作者：
L. Wen;M. C. Stordal;D. Tang;G. Gill;P. Santschi
中科院分区：
文献类型：
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作者：
L. Wen;M. C. Stordal;D. Tang;G. Gill;P. Santschi
进行了一系列实验室和现场研究，以测试Amicon超滤系统收集胶体物质的适用性和最佳采样条件，用于海洋环境中痕量金属相形态研究。在处理的每份样品之间需要进行清洁程序，以消除残留伪影并实现低系统空白。对于痕量金属（例如，Cd、Cu、Ni、Pb、Mn、Fe、Zn、Hg）。样品储存实验的结果表明，理想情况下，超滤应在4小时内进行样品采集，以防止相形态变化。渗透物部分中多种痕量金属的浓度作为浓度因子的函数作图时，发现符合Kilduff和Weber（1992）的稳态大分子渗透模型。基于对渗透金属浓度的建模，对于大多数金属，5至10之间的渗余物浓度因子是最佳的。对于加尔维斯顿湾，胶体级分（1 kDa-0.45 μm）占过滤级分（< 0.45 μm）中Cu的65-85%、Ni的35-40%和Pb的30-95%。在胶体比对的深太平洋水样中，胶体态Cu、Cuc（1 kDa-0.2 μ m）占64%，Ni C占6%，Pb C占9%。
A series of laboratory and field studies were conducted to test suitability and optimal sampling conditions of an Amicon ultrafiltration system for the collection of colloidal material for trace metal phase speciation studies in marine environments. A cleaning procedure is required between each sample processed to eliminate carry-over artifacts and achieve a low system blank. Mass-balance recovery of 88–109% was achieved for ultrafiltration of trace metals (e.g., Cd, Cu, Ni, Pb, Mn, Fe, Zn, Hg) from estuarine samples. Results of sample storage experiments indicate that ultrafiltration should ideally be performed within 4 h of sample collection to prevent phase speciation shifts. The concentration of a number of trace metals in the permeate fraction, when plotted as a function of concentration factor, was found to fit the steady-state macromolecular permeation model of Kilduff and Weber (1992). A retentate concentration factor between 5 and 10 was optimal for most metals based on modeling the permeate metal concentration. For Galveston Bay, the colloidal fraction (1 kDa-0.45 μm) accounted for 65–85% of the Cu, 35–40% of the Ni, and 30–95% of the Pb in the filtered (< 0.45 μm) fraction. Colloidal Cu, Cuc(1 kDa-0.2 μm) was 64%, Nicwas 6%, Pbcwas 9% of the filtered (< 0.2 μm) fraction in deep Pacific water samples from the colloid intercomparison exercise.