A tungsten oxide coated wire electrode used as a pH sensor in flow injection potentiometry

In this study, a tungsten oxide wire electrode is described for use as a pH electrode in a portable battery-powered flow injection analyser described previously.(1) The tungsten oxide electrode exhibits a linear response of 4 4.8 +/- 0.5 mV change per pH unit over a wide range, pH 2-11 in the steady- state mode. In the flow injection mode, the tungsten oxide wire electrode e xhibited a slope of 42.4 +/- 0.9 mV per pH unit. The tungsten oxide electro de was employed to determine the pH of various alcoholic beverages and envi ronmental water samples.