多壁碳纳米管/铋膜修饰电极示差脉冲溶出伏安法测定水中镉和铅

Determination of Cadmium and Lead in Water by Differential Pulse Stripping Voltammetry with Multiwalled Carbon Nanotubes/Bismuth Modified Electrode

制备多壁碳纳米管/壳聚糖纳米复合物修饰玻碳电极,用于同位镀铋膜法连续测定水中镉和铅离子的含量。将多壁碳纳米管分散在壳聚糖溶液中,滴涂在玻碳电极表面制得修饰电极;在含铋的溶液中,采用示差脉冲溶出伏安法测定了镉、铅离子的浓度;考察了沉积电位、富集时间对溶出电流的影响。在优化的实验条件下,对浓度在0—0.2μm ol/L范围内的Cd2+和Pb2+进行了定量测定,金属离子浓度和峰电流有较好的线性关系,检出限分别为19nm ol/L和23nm ol/L。结果表明,本法测定结果准确度,灵敏度较高,重现性良好,可实现水中微量重金属离子的快速同时测定。

Multiwalled carbon nanotubes/chitosan modified glass carbon electrode was fabricated to simultaneously determined the contents of cadmium and lead ions in water by ex-situ bismuth film.Multiwalled carbon nanotubes were dispersed in the chitosan solution,and were dropped onto the surface of glass carbon electrode to form the modification of the electrode.The concentrations of cadmium and lead ions were measured by differential pulse stripping voltammetry in the solution containing bismuth.The effects of the deposition potential and deposition time on the stripping peak current were investigated.The concentration range from 0 to 0.2μmol/L simultaneously determined Cd2＋ and Pb2＋ in the optimal experimental conditions.The stripping peak currents changed lineally with the concentrations of Cd2＋ and Pb2＋,and the detection limits were 19nmol/L and 23nmol/L,respectively.The method has good accuracy,sensitivity and reproducibility,that is utilized for the rapid and simultaneous determination of heavy metal ions in water.