Multi-wall carbon nanotubes (MWCNT) were dispersed in chitosan (CTS) solution, and the mixture obtained was used in modifying the surface of glassy carbon electrode (GCE) to prepare chitosan-multi-wall carbon nanotubes modified glass carbon electrode (CTS-MWCNT-GC). The stripping voltammetric characteristics of palladium(Ⅱ) at this electrode were studied with differential pulse stripping voltammetry. A new method for the determination of trace palladium(Ⅱ) was described after the determination conditions were optimized. It was found that palladium(Ⅱ) could be enriched on the surface of this modified electrode at -400 mV in 0.1mol/L sodium acetate -0. 1 mol/L hydrochloric acid buffer solution (pH 4. 10). When scanning from -300 mV to 400 mV at the rate of 100 mV/s, ,a sensitive differential pulse stripping peak appeared at 135 mV (vs. SCE) for palladium(ID. The peak current showed good linearity with the concentration of palladium in the range of 1. 88 × 10-9-1. 69 × 1O-8 mol/L. Detection limit was 3. 10 × 10-10 mol/L. The modified electrode showed good stability and reproducibility. The relative standard deviation (RSD) was 0. 21 ％ for 11 continuous determinations of 1.0×10-9 mol/L Pd(Ⅱ) solution. This method has been applied to the determination of trace palladium in ore samples, and the results were consistent with those obtained by FAAS.%将多壁碳纳米管(MWCNT)分散于壳聚糖(CTS)溶液中,修饰在玻碳电极(GCE)表面,制成了壳聚糖-多壁碳纳米管修饰玻碳电极(CTS-MWCNT-GCE).利用差分脉冲溶出伏安法研究了钯(Ⅱ)在该电极上的溶出伏安特性,优化了试验条件,提出了一种测定痕量钯(Ⅱ)的新方法.试验发现,在0.1 mol/L乙酸钠-0.1 mol/L盐酸缓冲溶液(pH 4.10)中,钯(Ⅱ)于-400 mV处被富集在该修饰电极表面,在-300 mV～400 mV电位范围内,以100 mV/s的速率扫描,钯(Ⅱ)在135 mV(vs.SCE)处出现一灵敏的溶出峰,峰电流与钯的浓度在1.88×10-9～1.69×10-8 mol/L范围内呈良好的线性关系,检出限为3.10×10-10mol/L.该修饰电极具有良好的稳定性和重复性,在含有1.0×10-9 mol/L钯的溶液中,连续11次测定,其相对标准偏差(RSD)为0.21%.方法用于矿样中痕量钯(Ⅱ)的测定,测定结果同火焰原子吸收光谱法(FAAS)的测定结果基本一致.
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