We constructed, tested and applied a tubular 5-ethyl-5-phenylbarbiturate ion-selective electrode based on tetraoctylammonium 5-ethyl-5-phenylbarbiturate dissolved in o-nitrophenyl octyl ether and immobilized on poly(vinyl chloride). The intrinsic features of the proposed electrode were assessed by using a low-dispersion single-channel flow injection analysis (FIA) system for performing repeated calibrations with sodium 5-ethyl-5-phenylbarbiturate standards, whose ionic strength was adjusted to 0.1 M with 0.033 M sodium sulfate. The determination of 5-ethyl-5- phenylbarbiturate in pharmaceutical preparations was accomplished by intercalating the proposed electrode into a twochannel FIA manifold. The results obtained were compared with those provided by the British Pharmacopoeia standard method. © 1992, The Japan Society for Analytical Chemistry. All rights reserved.
- Flow injection analysis
- pharmaceutical preparation
- tubular ion-selective electrode