【摘要】 Rh(Ⅲ)-2-(6-甲基苯并噻唑偶氮)-5-二乙氨基苯甲酸络合物在pH=5.0的HAc-NaAc缓冲液中有一较灵敏的极谱波,其峰电位EP1为-554 mV(vs.SCE),加入表面活性剂十二烷基苯磺酸钠使峰电流增加8.7倍,峰电位EP1负移至-600 mV(v.s SCE)。铑的质量浓度在0.05~65μg/L与二阶导数峰电流IP”有良好的线性关系,检出限为7.8 ng/L。经多种电化学方法证明该波为络合吸附波,其电极过程为不可逆,电子转移数为2。此外试验了多种共存离子对峰电流IP”测量的影响。所拟方法已用于13X分子筛催化剂中痕量铑的测定。结果与推荐值基本相符,6次测定的相对标准偏差(RSD)为3.6%。更多还原

【Abstract】 In HAc-NaAc buffer solution(pH=5.0) rhodium(Ⅲ)-2-(6-methylbenzothiazolyazo)-5-diethyl-aminobenzoic acid(6-Me-BTAEB) complex produces a sensitive polarographic wave at potential of-554 mV(vs.SCE). In presence of sodium dodecyl benzene sulfonate the second-order derivative peak current increases by a factor of 8.7 and the potential moves to-600 mV.A linear range of 0.05～65 μg/L for rhodium(Ⅲ) with a detection limit of 7.8 ng/L is obtained.This polarographic wave is proved to be an adsorptive wave of the rhodium complex and the elecurode process is an irreversible reduction process with two electrons transferred.The interference from coexistent ions on the peak currents is investigated.The proposed method has been applied to the determination of trace rhodium in 13X sieve catalysts with satisfactory results.更多还原