Potentiometric Sensor Based on Molecularly Imprinted Polymers for Rapid Determination of Clenbuterol in Pig Urine

A polymeric membrane ion-selective electrode for determination of clenbuterol is described. It is based on a molecularly imprinted polymer as an ionophore for molecular recognition, which can be synthesized by precipitation polymerization using clenbuterol hydrochloride as the template molecule. Under optimized conditions, the proposed membrane electrode exhibits Nernstian response to the protonated clenbuterol over the concentration range of 1.0 x 10(-7) M to 1.0 x 10(-4) M with a slope of 55.7 mV/dec., and a detection limit of 7.0 x 10(-8) M. The MIP-based sensor shows excellent selectivity, rapid response time and satisfactory long-term stability. The potentiometric sensor has been successfully applied to the determination of clenbuterol in pig urine samples with recoveries between 98% and 107% and an analysis time of less than 3 min.