Square Wave Voltammetric Determination of Lead(II) Ions Using a Carbon Paste Electrode Modified by a Thiol-Functionalized Kaolinite
Square Wave Voltammetric Determination of Lead(II) Ions Using a Carbon Paste Electrode Modified by a Thiol-Functionalized Kaolinite
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DOI：
10.1002/elan.201000467
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发表时间：
2011
期刊：
影响因子：
3
通讯作者：
I. Tonle;S. Letaief;E. Ngameni;A. Walcarius;C. Detellier
中科院分区：
文献类型：
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作者：
I. Tonle;S. Letaief;E. Ngameni;A. Walcarius;C. Detellier
本文报道了用一种新型的硫醇官能化粘土修饰的碳糊电极在水介质中对铅(II)的电分析。后者是通过将3-氯丙基三乙氧基硅烷接枝到高岭石的层间表面上，然后在严格控制的条件下用硫醇基团取代氯得到的。以原料高岭石及其二甲基亚砜(DMSO)插层为原料，用X射线衍射仪、热分析、红外光谱和CHNS元素分析对杂化产物进行了表征。这些技术证明了有机硅烷分子取代了DMSO，有机硅烷分子接枝在高岭石表面的内部羟基上。最终得到化学式为Si4Al4O10(OH)6[O2Si(OEt)(CH2)3SH]的功能化高岭土作为铅(II)传感电极改进剂。方波伏安法采用基于开路积累的两步分析方法。对影响两步测定的各种参数进行了优化：铅(II)浓度在3×10−7~10−5 M范围内与峰面积呈良好的线性关系，检出限为6×10−8 M。
This work reports the electroanalysis of lead(II) in aqueous medium, using a carbon paste electrode modified by a novel thiol-functionalized clay. This later was obtained upon the grafting of 3-chloropropyltriethoxysilane onto the interlayer surfaces of kaolinite, followed by the substitution under carefully controlled conditions of chloro by thiol groups. The raw kaolinite, its dimethylsulfoxide (DMSO) intercalate used as starting material and the resulting hybrids were characterized by X-ray diffraction, thermal analysis, infrared spectroscopy and CHNS elemental analysis. These techniques demonstrated the displacement of DMSO by the organosilane molecules which were grafted on the internal hydroxyl groups located on the kaolinite surface. The final functionalized kaolinite, with approximate chemical formula Si4Al4O10(OH)6[O2Si(OEt)(CH2)3SH] was evaluated as electrode modifier for lead(II) sensing. A two-step analytical procedure based on the accumulation at open circuit–detection was applied by square wave voltammetry. Various parameters affecting both the two steps were optimized: a linear response to lead(II) was obtained in the concentration range from 3×10−7 to 10−5 M, with a detection limit estimated at 6×10−8 M. The interfering effect of some ions likely to influence the stripping determination of lead(II) ions was evaluated, and the proposed method applied to a real sample.