Development of an on-line molecularly imprinted chemiluminescence sensor for determination of trace olaquindox in chick feeds.

Olaquindox, as one of the antimicrobial growth accelerants, is usually used in livestock production to improve feed efficiency. Due to health concerns over possible carcinogenic, mutagenic and photoallergenic effects of olaquindox on animals, the development of simple, rapid and sensitive analytical method for determination of olaquindox is crucial and necessary. In this study, a surface molecularly imprinted polymer was prepared by a molecular imprinting technique in combination with a sol-gel process using activated silica gel as a support material. This imprinted material exhibited with good recognition and selective ability, and fast adsorption-desorption dynamics toward olaquindox. Using it as the recognition element, a new on-line molecularly imprinted solid phase extraction coupled with chemiluminescence sensor for the determination of olaquindox was developed. The factors affecting preconcentration of the analytes and sensitivity of the method were all investigated. Under the optimal condition, the linear range of the calibration graph was between 2 × 10(-8) and 1 × 10(-6) g mL(-1) , and the detection limit of this method was 7 × 10(-9) g mL(-1) . The blank chick feed samples spiked with olaquindox at 0.3, 0.9 and 1.5 µg g(-1) levels were extracted and determined by this presented method with recoveries ranging from 87% to 94%. This method was validated by high-performance liquid chromatography and the results correlated well with those obtained by both methods. Moreover, this method was quantitatively analysed with two contaminated chick feed samples. This study will provide a sensitive and fast method for the monitoring of olaquindox residues in foods.