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Application of Polymer‐Modified Hanging Mercury Drop Electrode in the Indirect Determination of Certain β‐Lactam Antibiotics by Differential Pulse, Ion‐Exchange Voltammetry
Author(s) -
Prasad Bhim Bali,
Arora Bhavana
Publication year - 2003
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200390149
Subject(s) - chemistry , hanging mercury drop electrode , detection limit , ionic strength , oxazolone , electrode , aqueous solution , analytical chemistry (journal) , inorganic chemistry , nuclear chemistry , voltammetry , chromatography , electrochemistry , organic chemistry
A selective and sensitive polymer‐modified electrode was developed for β‐lactam antibiotics (cefaclor, amoxycillin and ampicillin) present in formulated and blood plasma samples for the quantitative analysis in aqueous environment. The detection was made using an ion‐exchange voltammetric technique, in differential pulse mode, on poly( N ‐chloranil N , N , N ′, N ′‐tetramethylethylene diammonium dichloride)‐modified hanging mercury drop electrode of a three‐electrode system (PAR Model 303A) attached with a Polarographic Analyzer/Stripping Voltammeter (PAR Model 264A). Antibiotics, which are electroinactive compounds, were essentially converted to their electroactive oxazolone analogues through acid treatment under drastic conditions (0.1 mol L −1 HCl, ∼85 °C, 2 h). These analytes in the form of their respective oxazolones were indirectly analyzed by oxazolone entrapment in the polymeric film through ion‐exchange process at modified electrode surface (accumulation potential −0.20 V (vs. Ag/AgCl), accumulation time 120 s, pH 7.4, KH 2 PO 4 ‐NaOH buffer (ionic strength 0.1 mol L −1 ), scan rate 10 mV s −1 , pulse amplitude 25 mV). The limit of detection of cefaclor‐derived oxazolone was found to be 2.12 nmol L −1 (0.82 ppb, S/N 3, RSD 3.21%) in terms of cefaclor (a representative β‐lactam) concentration.