A novel continuous-flow sequential extraction procedure for metal speciation in solids.
A novel continuous-flow sequential extraction procedure for metal speciation in solids.
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DOI：
10.2134/jeq2001.3041195x
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发表时间：
2001
影响因子：
2.4
通讯作者：
J. Shiowatana;N. Tantidanai;S. Nookabkaew;D. Nacapricha
中科院分区：
文献类型：
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作者：
J. Shiowatana;N. Tantidanai;S. Nookabkaew;D. Nacapricha
开发了一种连续流萃取系统，以加速、促进和提高固体材料中金属的化学分馏的准确性。通过分析土壤认证参考物质（美国国家标准与技术研究所[NIST] SRM 2710）中的钙（Ca）、铁（Fe）、锰（Mn）、铜（Cu）和锌（Zn），使用三步连续提取方案来评估新系统。在所提出的系统中，萃取发生在一个封闭的腔室中，萃取剂依次通过该腔室。将提取物收集成许多亚馏分，用于随后的原子吸收分析。除了流动分析系统通常具有的简单、快速和污染风险小的优点外，连续流动系统还可以通过连续萃取提高金属化学分馏的准确性。该系统确保在指定的pH值下进行提取，而无需进行任何调整。样品重量与腔室体积比从1：12到1：40的变化对所研究金属的可浸提性没有影响。在酸溶性部分的提取中，乙酸的浓度在0.11至0.5 mol L（-1）的范围内没有显着影响的金属提取量，除了铁。在还原性馏分步骤中，羟胺的浓度从0.04增加到0.5 mol L（-1），影响了Fe、Mn和Zn的萃取效率。每种元素的提取曲线，而不是提取浓度的单个值，提供了关于浸出过程的动力学和固体材料中元素之间的化学关联的额外信息。
A continuous-flow extraction system was developed to speed up, facilitate, and improve the accuracy of the chemical fractionation of metals in solid materials. A three-step sequential extraction scheme was used to evaluate the novel system by analyzing calcium (Ca), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in a soil certified reference material (National Institute of Standards and Technology [NIST] SRM 2710). In the proposed system, extraction occurred in a closed chamber through which extractants were passed sequentially. The extracts were collected in a number of subfractions for subsequent name atomic absorption analysis. Apart from the advantages of simplicity, speed, and less risk of the contamination that flow analysis systems usually possess, the continuous-flow system can improve the accuracy of chemical fractionation of metals by sequential extraction. The system ensures that extraction is performed at designated pH values without any need of adjustment. Variation of sample weight to chamber volume ratios from 1:12 to 1:40 had no effect on the extractability of the metals studied. In the extraction of the acid soluble fraction, concentrations of acetic acid in the range 0.11 to 0.5 mol L(-1) had no significant effect on the amounts of metals extracted, except Fe. Increasing the concentration of hydroxylamine in the reducible fraction step from 0.04 to 0.5 mol L(-1) affected the extraction efficiency for Fe, Mn, and Zn. The extraction profile, rather than a single value of extracted concentration, of each element offers additional information about the kinetics of leaching processes and chemical associations between elements in the solid materials.