Membrane-covered Sensors Using Propylene Carbonate Electrolytes Gelled by Highly Dispersed Silica for Amperometric Determination of Oxygen Gas Concentration

抄録

This paper describes the response characteristics of membrane-covered oxygen sensors using 0.1M tetramethylammonium perchlorate-propylene carbonate (TMAP-PC) electrolyte and highly viscous TMAP-PC-SiO₂ electrolytes containing an inorganic gelling agent of ultrafine SiO₂. The polarographic sensors consisted of a poly(tetrafluoroethylene) film, a gold-plated working electrode, 4cm³ of electrolyte, a Sn counter electrode and a Ag quasi-reference electrode. With the working electrode controlled at -1.1V vs. the Ag electrode, a similar linear relation with a sensitivity of 34-42 μA was found between the diffusion-controlled limiting current and oxygen partial pressure for all the PC-based electrolytes. The gelled electrolyte have the merit that there is no fear of CO₂ interference, leakage, and deposition of the cell-reaction product on the working electrode.