The measuring properties of
antimony electrodes were improved by the introduction of highly purified crystallographically oriented monocrystalline
antimony (
COMA).
COMA electrodes are sensitive to pH and pO2. For measurements of either pH, pO2, or both, the pH and the pO2 sensitivities must be known and the components of the composite
electrode signal must be separable. The
oxygen sensitivity of
COMA electrodes in vivo have been shown to be higher than in vitro in the pO2 range below 10 kPa. The present study was performed in an animal model to investigate the
oxygen sensitivity and to further evaluate the tissue pO2 measuring properties of a miniaturized six channel
COMA microelectrode. The results show that the
COMA microelectrode has negligible drift, a response time of less than 5 s and high sensitivity and reproducibility for tissue pO2 measurements when the pH part of the
electrode signal is eliminated. The
oxygen sensitivity found (8.5 +/- 0.4 (mV/pO2) (mean +/- SEM)), is described by a direct linear function in the
oxygen tension range studied. It is concluded that tissue pO2 can be calculated after elimination of the pH part of the
electrode signal. A multichannel
COMA microelectrode possess characteristics suitable for in vivo
oxygen measurements and is therefore an interesting
complement to traditional tissue
oxygen sensors.