Study of an organically modified clay: Selective adsorption of heavy metal ions and voltammetric determination of mercury(II)

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• 作者：Newton L. Dias Filho and Devaney Ribeiro do Carmo
• 关键词：Adsorption ; Organo-clay ; Carbon paste electrodes ; Voltammetry ; Mercury ; Preconcentration
• 刊名：Talanta
• 出版年：2006
• 出版时间：15 January 2006
• 年：2006
• 卷：68
• 期：3
• 页码：919-927
• 全文大小：290 K

文摘

In this work, a hydrophilic clay, Na-montmorillonite from Wyoming, USA, was rendered organophilic by exchanging the inorganic interlayer cations for hexadecyltrimethylammonium ions (HDTA), with the formulae of [(CH₃)₃N(C₁₆H₃₃)]⁺ ion. Based on fact that organo-clay has high affinities for non-ionic organic molecules, 1,3,4-thiadiazole-2,5-dithiol was loaded on the HDTA-montmorillonite surface, resulting in the 1,3,4-thiadiazole-2,5-dithiol-HDTA-montmorillonite complex (TDD-organo-clay).

The following properties of TDD-organo-clay are discussed: selective adsorption of heavy metal ions measured by batch and chromatographic column techniques, and utilization as preconcentration agent in a chemically modified carbon paste electrode (CMCPE) for determination of mercury(II).

The main point of this paper is the construction of a selective sensor, a carbon paste electrode modified with TDD-organo-clay, its properties and its application to the determination of mercury(II) ions, as this element belongs to the most toxic metals. The chemical selectivity of this functional group and the selectivity of voltammetry were combined for preconcentration and determination.