ABSTRACT
Liberated ammonia gives rise to a constant potential, linearly related to the logarithm of the substrate concentration in the sample solution. The proposed coated-wire sensor is very selective toward antazoline cation with respect to many common inorganic and organic cations, sugars, and amino acids that are frequently present in biological fluids and pharmaceutical preparations. All the Triphenylstilbenylborate-based sensors exhibit negligible interference from common inorganic cations or from some amino acids and neurotransmitters. Campbell et al. have described plastic-membrane sensors responding to organic ions that were used to monitor the titrations of cyclizine hydrochloride and other drug substances with sodium tetraphenylborate solution. An ion-selective membrane sensor based on the high molecular weight ion-pairing agent, dinonylnaphthalene sulfonic acid, which showed a great selectivity for various large organic cations, has also been investigated for its response to phencyclidine cation. An organic solvent solution of the tetraphenylborate salt of the appropriate cation was used as a liquid membrane.
