钯-硫脲-碘酸钾体系极谱络合吸附波及其应用  

Polarographic complex adsorptive wave of palladium-thiourea-potassium iodate system and its application

作　　者：杜芳艳[1] 张亚[1] 邓保炜[1] 王星[1] 

机构地区：[1]榆林学院化学与化工学院,陕西榆林719000

出　　处：《冶金分析》2011年第8期44-47,共4页Metallurgical Analysis

基　　金：陕西省教育厅(2010JK925);陕西省科技厅(2010JM2017)资助项目

摘　　要：钯(Ⅱ)-硫脲-碘酸钾络合物在pH8.20 NH3.H2O-NH4Cl缓冲溶液中有一灵敏的吸附波,峰电位在-0.42 V(vs.SCE)左右,该波的二阶导数峰峰电流与钯质量浓度在0.60～2.20μg/L范围内呈线性关系(r=0.998 8),检出限为0.30μg/L。经多种电化学方法证明,该吸附波为络合物吸附波,其电极过程为不可逆过程。考察了多种离子对峰电流Ip''的影响。当测定0.1μg/L钯溶液时除Mo(Ⅵ)、Pb2+、Cd2+、Mn2+离子的允许量(分别为0.01μg/L、0.08μg/L、0.1μg/L、0.2μg/L)较低外,其他被试验的阳离子允许量都较高;但是,当溶液中的Mo(Ⅵ)、Pb2+、Cd2+、Mn2+离子超过允许量时可以加入酒石酸和二巯基丙醇进行掩蔽以消除干扰。所拟方法用于铝合金中微量钯(Ⅱ)的测定,测定结果的相对标准偏差为2.1%,加标回收率在95%～102%之间。The palladium（Ⅱ）-thiourea-potassium iodate complex had a sensitive adsorptive wave in NH3·H2O-NH4Cl buffer solution at pH 8.20,with peak potential at about-0.42 V（vs.SCE）.The second derivative peak current of this wave was linear to the mass fraction of palladium in the range of 0.60-2.20 μg/L（r=0.998 8）,and the detection limit was 0.30 μg/L.Several electrochemical methods proved that this adsorptive wave was complex adsorptive wave,and the electrode process was irreversible.The effect of several ions on peak current（Ip＇＇） was investigated.In the determination of 0.1 μg/L palladium,the tolerant amount of Mo,Pb2＋,Cd2＋ and Mn2＋ was low（0.01 μg/L,0.08 μg/L,0.1 μg/L and 0.2 μg/L,respectively）,but the tolerant amount of other testing cations was high.When the content of Mo,Pb2＋,Cd2＋ and Mn2＋ was beyond the tolerant amount,the interference could be eliminated by adding tartaric acid and dimercaprol for masking.The proposed method was applied to the determination of trace palladium（Ⅱ） in aluminium alloy.The relative standard deviation（RSD） of determination results was 2.1 %,and the recoveries of standard addition were 95 %-102 %.

关 键 词：钯 硫脲 碘酸钾 络合物吸附波 

分 类 号：O657.14[理学—分析化学]