Poly(vinyl chloride) membrane electrode on a graphite substrate for the potentiometric titration of tetramethylammonium bromide with sodium tetraphenylborate
Abstract
A poly(vinyl chloride) membrane electrode, based on the ion-pair complex of tetramethylammonium bromide (TMAB) with sodium tetraphenylborate, is described. The electrode exhibits a linear response with a slope of 49 mV per decade of concentration at 20 °C within the range 1 × 10–4–0.1 M TMAB, at an ionic strength of 0.1 M NaBr. The effect of the pH of the test solution and the interference of other cations and SiO44–(or silicate ions of lower charge such as HSiO43– or H2SiO42–) were studied. Potentiometric titration was used to determine TMAB, in the presence of SiO44–, with satisfactory results.