title: Neutral carrier electrode for continuous measurement of blood Ca2+ in the extracorporeal circulation.
abstract: A neutral-carrier-based Ca2+-selective electrode exposed to whole blood exhibited an EMF-stability better than 0.13 mV (approximately 1% change of the initial activity) during 3.7 to 6.6 h. It has been used successfully to monitor ionic Ca2+ in the extracorporeal circulation during administration of calcitonin to dogs. Data simulation shows that the apparent concentration of ionic Ca2+ is affected by the concentration of Na+. A variation in [Na+] by +/- 5 mmol/L from a value of 143 mmol/L used for the calibration leads to uncertainties of +/- 0.8% in the Ca2+ concentration and +/- 0.2% in the Ca2+ activity if 3 mol/L KCl is used as the reference electrode solution. When an isotonic solution was used as reference electrolyte, errors of +/- 0.8% and +/- 1.7%, respectively, were observed.
mesh_terms: D000818:Animals; D002116:Calcitonin / Q000008:administration & dosage; D002118:Calcium / Q000097:blood*; D003124:Colorimetry; D004285:Dogs; D004566:Electrodes; D005112:Extracorporeal Circulation; D008567:Membranes, Artificial; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D011199:Potentiometry / Q000295:instrumentation; D012964:Sodium / Q000097:blood
chemical_list: D008567:Membranes, Artificial; D002116:Calcitonin; D012964:Sodium; D002118:Calcium