A molecularly-imprinted polymer (MIP) was prepared by electropolymerization of pyrrole (Py) onto a stainless steel frit, using ochratoxin A (OTA) as the template, in order to make a micro solid phase preconcentration (μSPP) device. The OTA template was removed with 1% triethylamine (TEA) in methanol. Compared to non-imprinted polypyrrole (PPy), the molecularly-imprinted polypyrrole (MIPPy) enhanced the selective binding of OTA. The percentage recovery improved from 0 to 40% when the OTA sample solution was acidified with 1 M HCl (1% by volume). At a flow rate of 0.2 mL/min, maximum OTA binding was reached in 6 min after a total loading of 3.2 ng OTA. Final elution of the OTA was analyzed by high performance liquid chromatography (HPLC) with fluorescence detection, using 20:80 v/v acetonitrile-ammonia buffer (NH 4Cl/NH 3, 20 mM, pH 9.2) as the mobile phase. The MIPPy-μSPP-HPLC results clearly demonstrated that the MIPPy-μSPP device afforded selective preconcentration of OTA from red wine samples, at OTA concentration levels as low as 0.05 ppb, prior to HPLC analysis.

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Analytical and Bioanalytical Chemistry
Department of Chemistry

Yu, J.C.C. (Jorn C. C.), Krushkova, S. (Svetla), Lai, E.P.C, & Dabek-Zlotorzynska, E. (Ewa). (2005). Molecularly-imprinted polypyrrole-modified stainless steel frits for selective solid phase preconcentration of ochratoxin A. Analytical and Bioanalytical Chemistry, 382(7), 1534–1540. doi:10.1007/s00216-005-3342-x