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A carbon dioxide air-gap microelectrode based on a neutral hydrogen ion exchanger pH microelectrode

✍ Scribed by Yilong Ma


Publisher
Elsevier Science
Year
1990
Tongue
English
Weight
360 KB
Volume
186
Category
Article
ISSN
0003-2697

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✦ Synopsis


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.