Carrier Based Ion-Selective Liquid Membrane Electrodes and their Medical Applications

Abstract

In clinical diagnosis and therapy the Na+- and K+-concentrations in blood and urine are important parameters and are generally determined by flame photometry. During the past few years, however, in clinical laboratories potentiometrie Na+- and K+-measurements with ion-selective elctrodes have become of increasing importance (4). The use of such membrane electrodes would be especially attractive alternatives to flame photometry if direct measurements in whole blood and undiluted urine could be performed. In this case the potentiometric method would offer advantages such as continuous monitoring (1, 6, 8) and routine measurements of the ion-activities in undiluted samples (3, 7). Here we report on the use of such liquid membranes for Na+- and K+-measurements in undiluted urine samples.