有序介孔碳-壳聚糖修饰玻碳电极差分脉冲溶出伏安法测定痕量钯(Ⅱ)

Determination of trace palladium(Ⅱ) by differential pulse stripping voltammetry using ordered mesoporous carbon-chitosan modified glassy carbon electrode

将有序介孔碳（OMC）分散于壳聚糖（CTS）溶液中,修饰在玻碳电极表面,制成有序介孔碳-壳聚糖修饰玻碳电极（OMC-CTS-GCE）,研究了钯（Ⅱ）在该电极上的电化学行为,探讨了电极反应机理,对测定条件进行了一系列优化,提出了一种测定痕量钯（Ⅱ）的方法。在0.1mol·L^-1乙酸钠-0.1mol·L^-1的盐酸缓冲溶液中（p H=4.5）,钯（Ⅱ）在OMC-CTS-GCE电极上,于0.49 V处产生一灵敏的溶出峰,峰电流与钯（Ⅱ）的浓度在2.0×10^-6-1.8×10^-4mol·L^-1范围内呈良好的线性关系,检出限（S/N=3）为1.5×10^-6mol·L^-1,方法应用于矿样中痕量钯（Ⅱ）的测定,结果同火焰原子吸收光谱法（FAAS）的测定结果基本一致。

The mixture solution of ordered mesoporous carbon（ OMC） and chitosan（ CTS） was modified on the surface of glassy carbon electrode（ GCE） to obtain ordered mesoporous carbon-chitosan modified glassy carbon electrode（ OMC-CTS-GC）. The electrochemical behavior of palladium（ Ⅱ） at OMC-CTS-GC and the corresponding reaction mechanism of electrode reaction were investigated. With optimizing the determination conditions,a new method for the determination of trace palladium（ Ⅱ） was proposed. It was found that in 0. 1 mol·L^-1Na Ac-0. 1 mol·L^-1HCl buffer solution（ p H 4. 5）,palladium（ Ⅱ） on OMC-CTS-GC showed a sensitive stripping peak at 0. 49 V. The peak current showed good linearity with the concentration of palladium（ Ⅱ） in the range of 2. 0×10^-6- 1. 8×10^-4mol·L^-1. Detection limit（ S / N = 3） was 1. 5×10^-6mol·L^-1. The procedure was applied to the determination of trace amounts of palladium in ore samples,and the results were consistent with those obtained by FAAS.