| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ion sensor in which, even when it is used repeatedly, composition of an ion sensing membrane is constant without being changed, by a method wherein content of a palsticizer in the ion sensing membrane is set at less than a specific wt.%. SOLUTION: In a sensor, an ion sensor plate body 5 in which at least a pair of a sample-liquid measuring electrode 2a comprising an ion sensing membrane 2d as a coating membrane and a reference electrode are formed as a set, a closed flow passage which supplies a sample liquid to the sample- liquid measuring electrode 2a and a closed flow passage which supplies a reference liquid to the reference electrode are formed respectively on a substrate. In addition, the sensor is provided at least with an upper-part cell which comprises a sample-liquid charging part and a reference-liquid charging part which communicate with the respective flow passages, and with a liquid-junction part which is installed at the ion sensor plate body 5 and which liquid-joins the sample liquid and the reference liquid which are supplied to the respective flow passages. The ion sensing membrane 2d contains at least a matrix, a plasticizer which plasticizes the matrix and an ion sensing substance. The content of the plasticizer in the ion sensing membrane is set at less than 60 wt.%. |
