IFCC reference methods and materials for measurement of pH, gases and electrolytes in blood

The Scientific Division Committee on pH, Blood Gases and Electrolytes (SD-CBGE) and Working Group on Selective Electrodes (SD-WGSE) of the International Federation of Clinical Chemistry (IFCC) produced recommendations to attempt to make the results of pH, blood gas and electrolyte analysis from different clinical chemistry laboratories internationally compatible. The aim of this paper is to present an updated version of a previous review of the essential aspects of: 1. the IFCC approved (1986) reference method for pH measurement in blood, 2. the IFCC approved (1988) reference method for tonometry of blood, 3. the provisionally proposed recommendations on the expression of results obtained with Ion-Selective Electrodes (ISE's) for sodium, potassium and ionized calcium measuring in serum, plasma or blood and 4. the provisionally proposed reference method for the determination of ionized calcium in serum, plasma or blood. Also reference materials for quality control of pH, blood gas and electrolyte measurements are discussed.