Hollow fiber membrane-protected molecularly imprinted microspheres for micro solid-phase extraction and clean-up of thiabendazole in citrus samples.

In the present work, molecularly imprinted polymer (MIP) microspheres were packed in polypropylene hollow fiber (HF) segments for the micro solid-phase extraction and clean-up of thiabendazole (TBZ) in citrus samples. Experimental parameters affecting TBZ extraction were carefully optimized. Hollow fiber membrane was able to protect MIP beads from solid matrix allowing the extraction and clean-up without the inclusion of further filtration and/or centrifugation steps. Under optimum experimental conditions, recoveries for TBZ at 0.83 mg kg-1 concentration level ranged from 5.1 to 6.1%, depending upon the sample analyzed (orange or lemon peel samples), with relative standard deviations (RSDs) lower than 4%. The limits of detection were 0.004 mg kg-1 in orange and 0.009 mg kg-1 in lemon, low enough for the determination of TBZ according to European Union legislation.