Siamionau Andrei V, Egorov Vladimir V
Laboratory of the Physical Chemical Investigation Methods, Research Institute for Physical Chemical Problems of the Belarusian State University, Leningradskaya Str., 14, 220006 Minsk, Belarus.
Analytical Chemistry Department, Faculty of Chemistry, Belarusian State University, Leningradskaya str., 14, 220030 Minsk, Belarus.
Membranes (Basel). 2022 Oct 20;12(10):1019. doi: 10.3390/membranes12101019.
An experimentally simple method for the direct determination of single-ion partition coefficients between water and a PVC membrane plasticized with o-NPOE is suggested. The method uses the traditional assumption of equal single-ion partition coefficients for some reference cation and anion, in this case tetraphenylphosphonium (TPP) and tetraphenylborate (TPB). The method is based on an integrated approach, including direct study of some salts' distribution between water and membrane phases, estimation of ion association constants, and measurements of unbiased selectivity coefficients for ions of interest, including the reference ones. The knowledge of distribution coefficients together with ion association constants allows for direct calculation of the multiple of the single-ion partition coefficients for the corresponding cation and anion, while the knowledge of unbiased selectivity coefficients together with ion association constants allows for immediate estimation of the single-ion partition coefficients for any ion under study, if the corresponding value for the reference ion is known. Both potentiometric and extraction studies are inherently equilibrium-based techniques, while traditionally accepted methods such as voltammetry and diffusion are kinetical. The inner coherent scale of single-ion partition coefficients between water and membrane phases was constructed.
提出了一种实验上简单的方法，用于直接测定水与用邻硝基苯辛醚增塑的聚氯乙烯膜之间的单离子分配系数。该方法采用了一些参考阳离子和阴离子具有相等单离子分配系数的传统假设，在这种情况下为四苯基鏻（TPP）和四苯基硼酸盐（TPB）。该方法基于一种综合方法，包括直接研究某些盐在水相和膜相之间的分布、估计离子缔合常数以及测量感兴趣离子（包括参考离子）的无偏选择性系数。分配系数与离子缔合常数的知识允许直接计算相应阳离子和阴离子的单离子分配系数的倍数，而无偏选择性系数与离子缔合常数的知识允许在已知参考离子相应值的情况下，立即估计任何研究离子的单离子分配系数。电位滴定和萃取研究本质上都是基于平衡的技术，而传统上公认的方法如伏安法和扩散法是动力学方法。构建了水相和膜相之间单离子分配系数的内部连贯尺度。
