Polarography.

摘要

The determination of the concentration of compounds such as CO<Sub>2</Sub> having an influence on the pH of a medium during polarography is described. Characteristics of potaro- grams when obtained in unbuffered electrolytes (the polarogram plateau slope position of the upper knee and half-wave potential thereof) are pH-sensitive. These can be detected electronically and signals processed to provide a measure of such concentrations.

In one preferred embodiment (Figure 2) a miniature pO<Sub>2</Sub> polarographic sensor has cathode channels (A) and (B) biased respectively at -750 mV and -950 mV. The output of channel (A) provides p0<Sub>2</Sub> as in normal polarography. The output of (B) is divided (6) and further corrected for p0<Sub>2</Sub> (8,10) to provide pC0<Sub>2</Sub>.

The apparatus is especially useful for simultaneous p02, pC02 monitoring in physiological fluids without the need for a separate pCO2 sensor.