A solid binding matrix/molecularly imprinted polymer-based sensor system for the determination of clenbuterol in bovine liver using differential-pulse voltammetry

A selective and sensitive method has been developed for the determination of clenbuterol in bovine liver samples using differential-pulse voltammetry (DPV), based on the electrochemical behaviour of clenbuterol at a molecularly imprinted polymer (MIP)-modified solid binding matrix composite electrode (SBMCE). The method of clenbuterol detection involves two steps. In the first step, clenbuterol binds selectively to the MIP. In the second step, an electroinactive competitor (isoxsuprine) is added in excess, whence some of the bound clenbuterol is released. The released clenbuterol is analysed using DPV. The electrode renewal was achieved by a simple mechanical polishing step of the SBMCE surface. The determination of clenbuterol in bovine liver fortified with increasing concentrations of this drug is also described, involving liquid-liquid extraction followed by a mixed-mode solid-phase extraction procedure. The integrated MIP-SBMCE displays good mechanical properties, electrochemical performances and can be a very useful tool in monitoring the use of anabolics in meat production. (C) 2001 Elsevier Science B.V. All rights reserved.