title: A novel combinational pH-PCO2 microelectrode.
abstract: A novel combinational pH-PCO2 microelectrode based on a neutral carrier hydrogen ion exchanger is described. It is easy to fabricate and allows pH and PCO2 to be measured simultaneously. The microelectrode has a 5-microns tip. The PCO2 microelectrode exhibits a linear response in the range 1.75 x 10(-5)-10(-2) mol/liter with a Nernstian slope of 57.0 mV/decade at 25 degrees C. The detection limit is 10(-5) mol/liter. The pH microelectrode exhibits a linear response in the range pH 4-12 with a Nernstian slope of 60.0 mV/decade at 25 degrees C. The 95% steady-state response time of the PCO2 microelectrode is about 2 min, while it is about 10 s for pH microelectrode. The electromotive force drift is 4.3 mV/h (PCO2) and 2.6 mV/h (pH), respectively. The lifetime is 3 to 4 days. The microelectrode can measure pH and PCO2 in body fluids simultaneously with satisfactory results. It is also a good basic electrode for enzyme microelectrolysis.
authors.affiliation: Institute of Environmental Medicine, Tongji Medical University, Wuhan, People's Republic of China.
authors.forename: X
authors.initials: X
authors.lastname: Rao
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis / Q000097:blood; D005069:Evaluation Studies as Topic; D006863:Hydrogen-Ion Concentration; D008839:Microelectrodes; D011817:Rabbits; D015203:Reproducibility of Results
chemical_list: D002245:Carbon Dioxide