Improved detection limits and sensitivities of potentiometric titrations.
Improved detection limits and sensitivities of potentiometric titrations.
复制标题
提高电位滴定的检测限和灵敏度。
DOI：
10.1021/ac001475b
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发表时间：
2001
影响因子：
7.4
通讯作者：
Pretsch,E
中科院分区：
文献类型：
--
作者：
Peper,S;Ceresa,A;Bakker,E;Pretsch,E
通过离子选择电极聚合物膜的零电流离子流会导致电位滴定终点偏置。通过选择合适的内溶液，降低跨膜离子通量，消除了偏倚，提高了终点检测的灵敏度。令人惊讶的是，伊势膜，有一个显着的主要离子通量的内部解决方案显示出更大的灵敏度比预期的滴定理论，但是，根据实验条件，其应用程序可能会偏置的终点。使用最佳系统，现在可以在总样品浓度低于10- 6 M的情况下进行终点检测，如用Pb 2+溶液滴定EDTA所示。
Zero-current ion fluxes through polymer membranes of ion-selective electrodes (ISEs) may lead to biased endpoints of potentiometric titrations. The bias is eliminated, and the sensitivity of the end-point detection is improved through reducing transmembrane ion fluxes by an appropriate choice of the inner solution. Surprisingly, ISE membranes that have a significant primary ion flux toward the inner solution show much larger sensitivities than expected by titration theory; however, depending on the experimental conditions, their application may bias the endpoint. With the optimal systems, endpoint detection is now possible with total sample concentrations below 10-6M, as demonstrated by the titration of EDTA with a Pb2+solution.