Reference liquid
AssigneeRadiometer A/S
InventorTorben F. Christiansen
Life of this patent
Estimating the term…
Abstract
A reference liquid for calibration or quality control of instruments which determine ionized calcium and pH. The reference liquid contains both a particular calcium ion activity and a pH-buffer and can therefore be used for calibration of both the calcium-sensitive electrode and the pH-electrode in the instruments. The pH-buffer is a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6. The reference liquid has an ionic strength of 0.15-0.17, a buffer capacity .beta. in the range of 0.04-0.10 and is packed in glass ampoules.
Claims5
A process for calibration or quality control of instruments adapted to determine ionized calcium and pH in physiological liquids and containing a calcium-sensitive electrode and a pH-electrode, comprising subjecting the calcium-sensitive electrode and the pH-electrode to calibration or quality control with a reference liquid which, at a particular temperature simulates the physiological liquid's calcium ion activity and which in addition contains a pH-buffer consisting of a nitrogen-containing organic sulphonic acid and the salt of this acid, the acid having a pK in the range of 6.6-7.6 at 37.degree. C., the buffering capacity of the pH-buffer in the reference liquid being from about 0.04 to about 0.10, and the ionic strength of the reference liquid being 0.15-0.17.
Dependencies are inferred from the claim text.