We report a novel application of a carbon paste electrode modified with sodium dodecyl sulphate (SDS) intercalated kaolin clay for the electrochemical detection of Pb²⁺in aqueous medium using square wave voltammetry. SDS was used to modify a chemically purified kaolin clay via intercalation process to prepare a carbon paste electrode. The SDS kaolin clay was obtained by intercalation of SDS into the interlayer spaces of kaolinite in the presence of heat. The purified kaolinite and its SDS intercalate were characterised using techniques such as X-ray powder diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TGA), attenuated total reflection Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM), BET and CHNS elemental analysis. These techniques proved the successful intercalation of SDS into the interlayer spaces of the clay adsorbent. Various parameters affecting the electrochemical detection of Pb²⁺ were optimised. A linear current response was obtained in the concentration range of 1–100 ppb. The limit of detection was found to be 2.48 ppb. The proposed sensor also demonstrates good reproducibility after series of 10 repetitive measurements with a relative standard deviation (RSD) of about 6.30%. The interfering effects of some ions on the detection of Pb²⁺ were evaluated. The proposed sensor was applied for the determination of Pb²⁺ in a real water sample.

Open image in new window

我们报告了十二烷基硫酸钠（SDS）插层高岭土修饰的碳糊电极在电化学检测Pb ^{2+中的新应用}在水介质中使用方波伏安法。SDS用于通过插层法对化学纯化的高岭土进行改性，以制备碳糊电极。通过在热存在下将SDS嵌入高岭石的层间空间中来获得SDS高岭土粘土。使用X射线粉末衍射（XRD），X射线荧光（XRF），热重分析（TGA），衰减全反射傅立叶变换红外光谱（ATR-FTIR），扫描电子等技术对纯化的高岭石及其SDS插层进行表征。显微镜（SEM），BET和CHNS元素分析。这些技术证明了将SDS成功嵌入到粘土吸附剂的层间空间中。影响Pb ²⁺电化学检测的各种参数被优化。在1-100 ppb的浓度范围内可获得线性电流响应。发现的检出限为2.48ppb。在一系列的10次重复测量之后，相对标准偏差（RSD）约为6.30％，所提出的传感器也显示出良好的重现性。评估了一些离子对Pb ²⁺检测的干扰作用。拟议中的传感器用于实际水样中Pb ^2+的测定。

在新窗口中打开图像