Problems Associated With the Use of the Exposed Platinum Electrode for Measuring Oxygen Tension in Vivo

The equation governing the distribution of oxygen around a stationary exposed platinum electrode was solved for the size of electrode used and for a number of different times. In protein solutions the oxygen polarogram could be satisfactorily monitored by measuring the diffusion current at −0.6 and −0.7 volts. After using the platinum electrode in solutions containing protein it was found necessary and sufficient to clean it in acid dichromate solution followed by neutralization in a buffer solution. This procedure reproduced the original diffusion current. In solutions containing heterogeneities with small coefficients of oxygen diffusion, the electrode current was found to be less than when the heterogeneities were not present.