Peper Shane, Gonczy Chad, Runde Wolfgang
Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Talanta. 2005 Oct 15;67(4):713-7. doi: 10.1016/j.talanta.2005.03.014. Epub 2005 Apr 14.
A new strategy for improving the robustness of membrane-based ion-selective electrodes (ISEs) is introduced based on the incorporation of microsphere-immobilized ionophores into plasticized polymer membranes. As a model system, a Cs(+)-selective electrode was developed by doping ethylene glycol-functionalized cross-linked polystyrene microspheres (P-EG) into a plasticized poly(vinyl chloride) (PVC) matrix containing sodium tetrakis-[3,5-bis(trifluoromethyl)phenyl] borate (TFPB) as the ion exchanger. Electrodes were evaluated with respect to Cs(+) in terms of sensitivity, selectivity, and dynamic response. ISEs containing P-EG and TFPB that were plasticized with 2-nitrophenyl octyl ether (NPOE) yielded a linear range from 10(-1) to 10(-5)M Cs(+), a slope of 55.4 mV/decade, and a lower detection limit (log a(Cs)) of -5.3. In addition, these membranes also demonstrated superior selectivity over Li(+), Na(+), and alkaline earth metal ion interferents when compared to analogous membranes plasticized with bis(2-ethylhexyl) sebacate (DOS) or membranes containing a lipophilic, mobile ethylene glycol derivative (ethylene glycol monooctadecyl ether (U-EG)) as ionophore.
基于将微球固定化离子载体掺入增塑聚合物膜中，引入了一种提高基于膜的离子选择性电极（ISE）稳健性的新策略。作为一个模型系统，通过将乙二醇功能化的交联聚苯乙烯微球（P-EG）掺杂到含有四[3,5-双（三氟甲基）苯基]硼酸钠（TFPB）作为离子交换剂的增塑聚氯乙烯（PVC）基质中，开发了一种Cs（+）选择性电极。从灵敏度、选择性和动态响应方面对电极进行了Cs（+）评估。用2-硝基苯基辛基醚（NPOE）增塑的含有P-EG和TFPB的ISE产生了10（-1）至10（-5）M Cs（+）的线性范围、55.4 mV/十倍的斜率和-5.3的较低检测限（log a（Cs））。此外，与用癸二酸双（2-乙基己基）酯（DOS）增塑的类似膜或含有亲脂性可移动乙二醇衍生物（乙二醇单十八烷基醚（U-EG））作为离子载体的膜相比，这些膜对Li（+）、Na（+）和碱土金属离子干扰物也表现出优异的选择性。
