Tetraphenylborate ion selective electrode based on plasticized poly(vinyl chloride) membrane containing no ion-exchange site and its application to potentiometric titration

The o-nitrophenyl octyl ether (o-NPOE)-plasticized PVC membrane electrode shows the linear response with potential slope of 50 mV per decade for tetraphenylborate (TPB^-) ion from 10^-5 M to 10^-2 M. The response time of the electrode is in the order of a few seconds. The electrode can be used in wide pH range, and is highly selective to the TPB^- ion over inorganic anions. The electrode is suitable as the end-point detector in the potentiometric titration of quaternary ammonium salts and potassium ion.