混合溶剂中性载体镁离子选择性微电极的研究

用氯化石腊和邻硝基苯辛醚为混合溶剂制备中性载体ETH5214的镁离子选择性微电极,相对于钾离子的电位选择性系数较单独以邻硝基苯辛醚为溶剂的ETH5214镁微电极改善0.9个数量级。在纯MgCl~2和在含细胞内典型离子背景的MgCl~2溶液中,响应斜率为Nernst响应,检测下限分别为4×10^-^7mol.dm^-^3和2×10^-^5mol.dm^-^3。在pH3.5-9.5范围内,氢离子对电极的电位响应无影响。测量的重现性良好。电极的实用响应时间(t~9~5)≤3s,有效寿命长于5天。

Magnesium-selective microelectrode based on a neutral carrier with mixed solvent

An intracellular ion-selective microelectrode based on the neutral carrier ETH5214 with chlorinated paraffin (60% Cl) and o- nitrophenyloctylether (o-NPOE) as solvents is presented. Compared with the sensor based on the same ionophore with solvent o-NPOE, the potentiometric selectivity factor for Mg^2^+ with respect to K^+ has been improved by 0.9 order of magnitude. The microelectrode shows a near-Nernstian response in pure MgCl~2 solutions and in the MgCl~2 solutions at a typical intracellular ion background, with detection limits of 4×10^-^7 mol.dm^-^3 and 2×10^-^5 mol.dm^-^3, respectively. The H^+ does not interfere with the emf response of the electrode in pH 3.5-9.5. The lifetime of the microelectrode cell assembly is longer than 5 days, and the response time (t~9~5)≤3s.