Abstract: There is presented a method of measuring one or more potential differences being indicative of one or more concentrations of one or more analyte ions in a sample, such as being a liquid whole blood sample, said method comprising, measuring with a reference ion measurement setup a parameter indicative of a concentration of a reference ion in the sample wherein the reference ion measurement setup is different from an electroanalytical measurement setup, measuring with an analyte ion measurement setup one or more potential differences directly or indirectly between each of one or more, optionally solid-state, working electrodes with each of said, optionally solid-state, working electrodes comprising an ion-selective electrode which is selective for an analyte ion, and an, optionally solid state, reference electrode which is selective for the reference ion wherein the analyte ion measurement setup is an electroanalytical setup. There is additionally presented an apparatus and use of said apparatus.

Abstract: A CO2-sensitive planar sensing device is disclosed, which has an electrode with an ion-selective layer, an electrolyte layer and an outer layer. The electrolyte layer has osmotically active species in an amount of 0.8-6.0 milliosmol per m2 of electrolyte layer area, and has a hydrophilic osmolarity increasing component which does not add bicarbonate ions or chloride ions to the electrolyte layer.

Abstract: A CO2-sensitive planar sensing device is disclosed, which has an electrode with an ion-selective layer, an electrolyte layer and an outer layer. The electrolyte layer has osmotically active species in an amount of 0.8-6.0 milliosmol per m2 of electrolyte layer area, and has a hydrophilic osmolarity increasing component which does not add bicarbonate ions or chloride ions to the electrolyte layer.

Abstract: The invention concerns an electrode device comprising an ion selective material, a solid state, inner reference system of sodium vanadium bronze and a contact material, where sodium may be reversibly intercalated, in the bronze. Such an electrode device may for instance be sensitive to ions, such as H+, Na+, K+and Ca2+. It may also include a reactive material in which a particular analyte is reacted to form an ion product, to which the ion selective material is sensitive, such as in electrode devices of the Severinghaus-type or in biosensors. The electrode device according to the invention can be prepared by thick film printing.