Cefuroxime selective electrodes for batch and FIA determinations in pharmaceutical preparations

• Type: Article in International Scientific Journal
• Date: 1998

Authors

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

Journal

Title: Journal of Pharmaceutical and Biomedical Analysis

Vol. 18

Pages: 93-103

ISSN: 0731-7085

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 18 Citations

Scopus - 17 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-71A

DOI: 10.1016/s0731-7085(98)00162-9

Abstract (EN): Different cefuroxime selective electrodes, without internal reference solution and comprising PVC membranes, were constructed and evaluated. Membranes were prepared with cefuroxime tetraoctylammonium (A) or cefuroxime bis(triphenylphosphoranylidene)ammonium (B) as ion-exchanger, 2-nitrophenyl octyl ether (X) or bis(2-ethyl hexyl)sebacate (Y) as plasticizing mediator solvent and 4-tert-otcylphenol (TOP) as additive. From the comparative evaluation of the described electrodes, membranes comprising 2-nitrophenyl octyl ether, cefuroxime tetraoctylammonium and 4-tert-otcylphenol presented better working characteristics. For these electrodes (type XA-TOP), with a lifetime > 5 months, a lower limit of linear range of 2.8 x 10(-4) M, a practical detection limit of 1.3 x 10-4 M, a reproducibility of similar to +/- 0.6 mV day(-1) and a slope of - 50.4 mV decade(-1), under H3PO4/NaH2PO4 solutions (pH 3.5; I = 0.1 M), were found. The presence of the additive on the membranes was of crucial importance for the electrodes good characteristics. Interference from sulphate, chloride, nitrate, iodide, cefaclor, cefadroxil, cefazolin and cephradine, on the electrodes behaviour was evaluated. Only a slight interference from nitrate and iodide was recorded, being type XA-TOP electrodes the most selective units. Electrodes with a tubular configuration prepared with type XA-TOP membranes, aiming flow injection analysis, were also constructed. When these tubular potentiometric detectors were evaluated in a double-channel flow injection manifold, with 3.5 pH and 0.1 M ionic strength conditions, significantly better working characteristics than those of the corresponding conventional electrodes, namely higher slopes (-54.6 mV decade(-1)) and better reproducibilities (+/-0.2 mV day(-1)); were found. Both conventional and tubular type XA-TOP electrodes were used for injections analyses by batch and FIA, respectively, presenting low consumption of samples and reagents. Relative error deviations to the reference procedures < 3.0% were found.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11