Synthesis of core-shell molecularly imprinted polymer microspheres by precipitation polymerization for the inline molecularly imprinted solid-phase extraction of thiabendazole from citrus fruits and orange juice samples

In this work, the synthesis of molecularly imprinted polymer microspheres with narrow particle size distributions and core-shell morphol. by a two-step pptn. polymn. procedure is described. Polydivinylbenzene (poly DVB-80) core particles were used as seed particles in the prodn. of molecularly imprinted polymer shells by copolymn. of divinylbenzene-80 with methacrylic acid in the presence of thiabendazole (TBZ) and an appropriate porogen. Thereafter, polymer particles were packed into refillable stainless steel HPLC columns used in the development of an inline molecularly imprinted SPE method for the detn. of TBZ in citrus fruits and orange juice samples. Under optimized chromatog. conditions, recoveries of TBZ within the range 81.1-106.4%, depending upon the sample, were obtained, with RSDs lower than 10%. This novel method permits the unequivocal detn. of TBZ in the samples under study, according to the max. residue levels allowed within Europe, in less than 20 min and without any need for a clean-up step in the anal. protocol.