A carbon dioxide air-gap microelectrode based on a neutral hydrogen ion exchanger pH microelectrode.
A relatively simple potentiometric pCO2 gas-sensing microelectrode is described. It is based on an ion-exchanger pH electrode, has a 2- to 5-microns tip, and has an air gap which is formed by means of hydrophobic treatments. The microelectrode exhibits a linear response in the range 10(-4)-10(-2) M with a Nernstian slope of 59 to 62 mV/decade at 25 degrees C. Ninety-five percent of the steady-state response time is about 20-30 s at the flow system when the concentration of sodium bicarbonate in buffer solution (pH 4.5) suddenly shifts from 0.2 to 2 mM and the lifetime is longer than 1 week.
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Institute of Environmental Medicine, Tongji Medical University, Hubei, People's Republic of China.
D000818:Animals; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods; D002245:Carbon Dioxide; D004563:Electrochemistry; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D008839:Microelectrodes; D051381:Rats
D002245:Carbon Dioxide; D006859:Hydrogen