Glass electrode measurements of blood sodium and potassium

WALTON. Glass electrode measurements of blood sodium and potassium in man. J. Appl. Physiol. 18(5) : g5oy54. 1963.-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