title: Interferent ion effects on the Orion SS-20 Calcium Ion Analyser.
abstract: Selectivity studies were carried out on bis-dialkyl phosphate and neutral carrier sensors available with the Orion SS-20 Calcium Analyser. Neutral carrier sensors showed better selectivity; changes of H+, Na+, K+ and Mg2+ within the physiological range produced no significant error in Ca2+ measurement. The Nicolsky equation, used as the basis of these studies, did not fully account for electrode response to mixed electrolytes. The importance of a check on the selectivity of sensors is emphasised.
mesh_terms: D002118:Calcium / Q000097:blood*; D002412:Cations; D004566:Electrodes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000097:blood; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood
chemical_list: D002412:Cations; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium