Abstract: A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity .beta. in the range of 0.04-0.10 and is packed in glass ampoules.

Abstract: An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2 O.sub.2.

Abstract: An electrochemical measuring electrode device (10) for polarographically measuring the partial pressure of oxygen in an electrolytic medium comprises a cathode (14) which is capable of reducing oxygen and defines an exposed oxygen-reducing cathode surface (20), an anode (18), which defines an exposed anode surface which is arranged relative to the exposed oxygen-reducing cathode surface so as to communicate electrolytically therewith through the electrolytic medium, and a membrane (24), which covers the exposed oxygen-reducing cathode surface and further defines an electrolyte chamber (22) in which the electrolytic medium is confined. In order to effectively promote the decomposition of H.sub.2 O.sub.2 generated in the electrolytic medium as an oxygen reduction intermediate and thereby reduce the response time of the electrode, a stable, non-biological catalytic means is provided catalytically communicating with the H.sub.2O 2.

Abstract: For continuous or intermittent monitoring or recording of the in vivo plasma pH of a patient, the patient's acid base status is established with performance of at least one in vitro determination on a blood sample from the patient, and for a period of some hours thereafter, the patient's in vivo plasma pH is determined on the basis of this initial acid base status and the results of non-invasive measurements of the patient's actual blood Pco.sub.2.

Abstract: A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity .beta. in the range of 0.04-0.10 and is packed in glass ampoules.