Determination of cefaclor by selective sample enrichment/clean-up on silica gel bonded polyelectrolyte in ion-exchange column chromatography

A silica gel-bound cationic polyelectrolyte, poly[N-chloranil N,N,N',N'- te tramethylethylene diammonium dichloride], modified as ion-exchanger capable of molecular recognition of B-lactam antibiotic, was used in solid phase e xtraction through column chromatography for a sample clean-up and enrichmen t of analyte from a dilute solution. The optimum and selective sorption con ditions for a model antibiotic, cefaclor, were established. The high select ivity of polymer at pH 9.5 and flow rate as high as 5 ml/min were observed for the quantitative sorption of cefaclor. The desorption by 0.1 N HCl at f low rate of 0.1 ml/min and subsequent heating at 80 degrees C for 2 h allow ed the antibiotic to be detected as corresponding oxazolone form in UV-spec trophotometric and differential pulse adsorptive stripping voltammetric mea surements. The potential of the suggested approach was illustrated by estim ating cefaclor in urine and blood plasma samples. (C) 2000 Elsevier Science B.V. All rights reserved.