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用十二烷基苯磺酸钠改性膨润土,并通过红外光谱(IR)及X射线衍射(XRD)对其进行表征。以改性膨润土作为化学修饰剂制成修饰碳糊电极,利用三电极体系循环伏安法,在BR缓冲溶液中测定铅离子(Pb~(2+))的电化学行为。结果表明:用十二烷基苯磺酸钠改性膨润土作为修饰剂提高了碳糊电极的电化学性能,使其对Pb~(2+)的电化学响应和选择性均得到提高。在改性膨润土质量分数为6%,以pH=2.4的BR缓冲溶液为底液的最佳检测条件下,Pb~(2+)响应电流与Pb~(2+)浓度(在0.120μmol/L范围内)呈良好的线性关系,相关系数为0.99492,检出限为6.531×10-8 mol/L。连续测定15d,电极表现出良好的稳定性。在最佳条件下,采用标准加入法对模拟水样中的Pb~(2+)进行测定,Pb~(2+)回收率在96.90%~103.75%之间。
Bentonite was modified with sodium dodecylbenzenesulfonate and characterized by infrared spectroscopy (IR) and X-ray diffraction (XRD). Modified bentonite was used as a chemical modifier to make a modified carbon paste electrode. The cyclic voltammetry was used to determine the electrochemical behavior of lead (Pb 2+) in BR buffer solution. The results showed that using sodium dodecyl benzene sulfonate modified bentonite as a modifier increased the electrochemical performance of the carbon paste electrode and improved its electrochemical response and selectivity to Pb 2+. Under the optimum condition of 6% bentonite modified with BR buffer solution of pH = 2.4, the response of Pb 2+ to Pb 2+ concentration (0.120 μmol / L Range) showed a good linear relationship, the correlation coefficient was 0.99492, the detection limit was 6.531 × 10-8 mol / L. Continuous determination of 15d, the electrode showed good stability. Under the optimum conditions, Pb2 + in simulated water sample was determined by standard addition method. The recovery of Pb2 + was between 96.90% and 103.75%.