【摘要】 <正> 离子选择电极（ISE）通常是基于能斯特响应来测定离子活度或浓度的。每一种ISE都存在着一个线性电位响应区域。为了满足线性响应的要求,待测组份浓度,介质酸碱度及共存的其它组份均受到较严格的限制。而许多实际体系（如混合稀土萃取体系）十分复杂,不仅待测组份浓度高,而且共存组份多,酸度变化也较大,电极在这类体系中常呈非线性响应。本工作报导CeO₂膜稀土ISE在非线性响应区域对单一稀土和混合稀土的响应特性,和半经验数学模型的探讨。更多还原

【Abstract】 The character of cerium oxide membrane ion-selective electrode （ISE） for individualand mixed rare earth system in the non-linear response region has been investigated.The potential of the linear response region of ISE for HCl-CeCl₃ system at pH = 4.9--6.0and rare earth conceniration （C） = 10^-2--10^-5M can be described as: E = -- 30 lgC_CeCl -- 47. 1 The relations of △E--C and △E--pH for HCl--PrCl₃ system show that when pH<2 the inter-ference is higher and the electrode can’t be used for the measurement. The relations of△E--C for two rare earths mixed （Pr--Nd）Cl₃ C = 0.25--0. 7M, four rare earths （La-Ce-Pr-Nd） Cl₃ C = 0. 14--0. 7M and fifteen rare earths （La--Lu） and Y C = 0.2--1. 0M systems in thepresence of NH₄Cl show that when pH≥ 2 the responses similar to those what in the indivi-dual rare earth, while pH < 2 the interference of the acidity is evident. A general, moreaccurate model for various systems is proposed through mathmatical simulation: E = B₁ lg [C_i +B₂ （C_i + C_j）^B_?]更多还原