Ion-selective electrodes for promethazine determinations in pharmaceutical preparations and application to flow injection analysis

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Lima, JLFC (Author) FFUP; Montenegro, MCBSM (Author) FFUP; Sales, MGF (Author) Other

Journal

Title: Journal of Pharmaceutical Sciences

Vol. 86

Pages: 1234-1238

ISSN: 0022-3549

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 17 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-ACS

DOI: 10.1021/js970171a

Abstract (EN): The construction and evaluation of PM-selective electrodes with a conventional configuration and without internal reference solution are described. Two different PVC membranes were prepared with PM tetraphenylborate dissolved in 2-nitrophenyl octyl ether (type A) or bis(2-ethylhexyl)sebacate (type B). When the electrodes were evaluated in 0.01 M ionic strength solutions, both presented linear responses from 5 x 10(-5) to 1 x 10(-2) Ni, slopes close to the theoretical value, practical detection limits of -2 x 10(-5) M, reproducibilities of +/-0.2 mV/day, and a quick response (<20 s), Using phosphate buffer solutions (pH 6.0), type B electrodes presented a lower practical detection limit and a better reproducibility than type A. Selectivity against several cations was assessed by the separated solutions method, and the type B electrodes were generally more selective. The type B membrane was also used for the construction of tubular electrodes for the automatic analysis of pharmaceutical products by flow injection analysis (FIA), These tubular detectors, evaluated in a low dispersion FIA system, presented better selectivity and sensitivity than the corresponding conventional ones. Several pharmaceutical preparations were analyzed with both conventional and tubular electrodes. The results obtained by FIA presented relative deviations of <2% when compared with those obtained from the United States Pharmacopoeia monographs.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5