title: Analysis of benzo[a]pyrene in vegetable oils using molecularly imprinted solid phase extraction (MISPE) coupled with enzyme-linked immunosorbent assay (ELISA).
abstract: This paper describes the development of a molecularly imprinted polymer-based solid phase extraction (MISPE) method coupled with enzyme-linked immunosorbent assay (ELISA) for determination of the PAH benzo[a]pyrene (B[a]P) in vegetable oils. Different molecularly imprinted polymers (MIPs) were prepared using non-covalent 4-vinylpyridine/divinylbenzene co-polymerization at different ratios and dichloromethane as porogen. Imprinting was done with a template mixture of phenanthrene and pyrene yielding a broad-specific polymer for PAHs with a maximum binding capacity (Q) of ~32 μg B[a]P per 50 mg of polymer. The vegetable oil/n-hexane mixture (1:1, (v/v)) was pre-extracted with acetonitrile, the solvent evaporated, the residue reconstituted in n-hexane and subjected to MISPE. The successive washing with n-hexane and isopropanol revealed most suitable to remove lipid matrix constituents. After elution of bound PAHs from MISPE column with dichloromethane, the solvent was evaporated, the residue reconstituted with dimethyl sulfoxide and diluted 100-fold with methanol/water (10:90, (v/v)) for analysis of B[a]P equivalents with an ELISA. The B[a]P recovery rates in spiked vegetable oil samples of different fatty acid composition were determined between 63% and 114%. The presence of multiple PAHs in the oil sample, because of MIP selectivity and cross-reactivity of the ELISA, could yield overestimated B[a]P values.
authors.affiliation: Institute of Hydrochemistry and Chemical Balneology, Chair for Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 Munich, Germany. michael.pschenitza@mytum.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Pschenitza
authors.affiliation: Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, Standort Marienfelde, Diedersdorfer Weg 1, 12277 Berlin, Germany. rudolf.hackenberg@bvl.bund.de.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hackenberg
authors.affiliation: Institute of Hydrochemistry and Chemical Balneology, Chair for Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 Munich, Germany. reinhard.niessner@ch.tum.de.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Niessner
authors.affiliation: Institute of Hydrochemistry and Chemical Balneology, Chair for Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, 81377 Munich, Germany. dietmar.knopp@ch.tum.de.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Knopp
mesh_terms: D001564:Benzo(a)pyrene / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D057230:Limit of Detection; D016014:Linear Models; D008752:Methylene Chloride; D054802:Molecular Imprinting / Q000379:methods*; D010938:Plant Oils / Q000032:analysis* / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D010938:Plant Oils; D001564:Benzo(a)pyrene; D008752:Methylene Chloride