氟离子选择性电极的内参比系统,通常是将内参比电极(如Ag/AgCl电极)插入标准电介质溶液(如10~(-3)M氟化钾溶液+10~(-1)M氯化钠溶液)中。若采用像银、镉等阳离子电极的银、铅、金、铝、石墨接触的内参比系统,电极功能变坏,重复性不好。这是因为内参比系统中缺乏氟离子,引起电极极化所致。我们采用掺钙(2％)、掺铕(Ⅱ) Fluorine ion-selective electrode internal reference system, usually the internal reference electrode (such as Ag / AgCl electrode) into the standard dielectric solution (such as 10 ~ (-3) M potassium fluoride solution +10 ~ (-1) M chloride Sodium solution). If the use of silver, cadmium and other cationic electrode silver, lead, gold, aluminum, graphite contact reference system, the electrode function deterioration, poor repeatability. This is due to the lack of fluoride ions in the internal reference system, resulting in electrode polarization. We use calcium (2%), doped europium (Ⅱ)