We are pleased to see that Coleman and Young agree with our original exhortation
concerning the need to establish the ranges for sodium and potassium in normal samples …

Biomedical, Newton, MA) ion-selective electrode type of analyzer relative to that obtained
with flame photometry. They were concerned because their results were in disagreement …

The observed reference ranges for sodium and potassium as determined by direct
potentiometry vary from instrument to instrument, depending on the composition of the …

To further the accurate direct potentiometry of plasma electrolyte concentrations, we
investigated the effects of solution composition on the residual liquid junction potential …

Two recent papers by Payne et a1.'S2 propose that an isotonic salt bridge of either 150
mmol/L KCl or NaCl may lead to improvements in performance over the hypertonic salt …

A previous communication(1) hypothesized that values for serum sodium and potassium ion
concentrations as measured by ion-selective electrode di-rect potentiometry(ISE/DP) should …

We compared different sample-handling techniques for measurement of Na+ and K+ with
ion-selective electrodes (ISE). Imprecision was less for venous blood (with a minimum of …

We measured the emf of a sodium ion-selective electrode in NaCl-NaHCO3 solutions (160
mmol of Na+, 160-120 mmol of Cl-, and 0-40 mmol HCO3-per liter) with a home-built cell in …

We measured the emf of NaCl solutions (120-160 mmol/L) with a home-built cell in steady-
state and with some commercial direct potentiometric analyzers about 20 s after the sample …

Materials and Methods Direct potentiometric analysis of sodium and potassium was done
with an Orion SS/30 sodium/potassium analyzer (Orion Biomedical, Inc., 11 Blackstone St …