Michalska Agata, Wojciechowski Marcin, Bulska Ewa, Mieczkowski Józef, Maksymiuk Krzysztof
Department of Chemistry, Warsaw University, Warsaw, Poland.
Talanta. 2009 Oct 15;79(5):1247-51. doi: 10.1016/j.talanta.2009.05.028. Epub 2009 May 23.
Poly(n-butyl acrylate) membranes for potentiometric ion-selective electrodes were developed and studied on example of lead-selective sensors. A novel approach resulting in Nernstian responses of tested sensor was proposed. Introduction of 5% (w/w) hydroxyethyl methacrylate into n-butyl acrylate moiety resulted in significant improvement of sensor analytical parameters. For the latter membrane material linear responses were obtained within lead activities range from 10(-2) to 10(-9) mol/dm(3), while for poly(n-butyl acrylate) based membranes pretreated in the same manner super-Nernstian behavior was obtained in a parallel experiment. Electrochemical impedance spectroscopy studies did not reveal significant differences between these two membranes, also similar lead ions diffusion coefficients were determined using inductively coupled plasma mass spectrometry with laser ablation.The difference between two kinds of membranes was found to concern higher Pb(II) ions contents in the surface part of the membrane with hydroxyethyl methacrylate, resulting in balanced Pb ions fluxes from/to the membrane.
以铅离子选择性传感器为例，开发并研究了用于电位型离子选择性电极的聚（丙烯酸正丁酯）膜。提出了一种使测试传感器呈现能斯特响应的新方法。在丙烯酸正丁酯部分引入5%（w/w）的甲基丙烯酸羟乙酯可显著改善传感器的分析参数。对于后一种膜材料，在铅离子活度范围为10⁻²至10⁻⁹ mol/dm³内获得了线性响应，而在平行实验中，以同样方式预处理的基于聚（丙烯酸正丁酯）的膜呈现超能斯特行为。电化学阻抗谱研究未揭示这两种膜之间的显著差异，使用电感耦合等离子体质谱结合激光烧蚀法测定的铅离子扩散系数也相似。发现两种膜的差异在于含甲基丙烯酸羟乙酯的膜表面部分的Pb(II)离子含量较高，从而使进出膜的铅离子通量达到平衡。
