Reference liquid for blood gas equipment

Abstract

A stable synthetic water based reference liquid for quality control and/or calibration of blood gas measuring equipment, said liquid being enclosed in a gas-tight container and containing HCO.sub.3.sup.- ions, H.sup.+ ions, CO.sub.2 gas, and O.sub.2 gas plus an additional pH buffer system different from the pH buffer system constituted by the HCO.sub.3.sup.- ions and the CO.sub.2 gas, said liquid showing, at a fixed temperature, known pH, pCO.sub.2 and pO.sub.2 values, said liquid additionally containing oxygen reversibly contained in a dispersed non-proteinaceous organic substance which shows higher solubility for oxygen than does water, and, optionally, a coloring component showing maximum or significant absorption at about 500 nm, said organic substance being (a) a water-insoluble organic substance in which O.sub.2 l is soluble to an extent of at least 12% by volume at 1 atmosphere oxygen pressure and 25.degree. C., said water-insoluble substance being a liquid of lipoid character emulsified in a liquid-in-water type emulsion, in the water base of the reference liquid, or a solid suspended in the water base of the reference liquid, or (b) an oxygen complex-forming metal organic compound of a transition group metal dissolved in the water base of the reference liquid, the stability constant of the oxygen complex of which metal organic compound is in the range of 1.times.10.sup.3 to 10.sup.5.5.

Dependencies are inferred from the claim text.