Glass electrode measurements of blood sodium and potassium in man

¹ Department of Anatomy, The University of British Columbia, Vancouver, Canada

A practical, simple procedure for the estimation of (Na⁺) and (K⁺) in undiluted whole blood or serum is presented. The method uses cation-responsive glass electrodes and is based on a graphic simplification of equations and on calibration steps for deriving the necessary constants. When one electrometer is used, the procedure requires about the same time as standard flame photometry; with two electrometers, it is faster. Values for (Na⁺) and (K⁺) in our series of 38 normal young adults compare well both absolutely and in terms of variability with recently published flame photometric measurements in protein-free samples. In a random series of hospital patients, occasional striking divergences suggest that ion binding as a factor in disease warrants further investigation.

Submitted on March 21, 1963