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 44.8 ± 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 exhibited a slope of 42.4 ± 0.9 mV per pH unit. The tungsten oxide electrode was employed to determine the pH of various alcoholic beverages and environmental water samples.