Molecularly imprinted solid-phase extraction for cholesterol determination in cheese products

A new sorbent for molecularly imprinted solid-phase extraction (MISPE) to detect cholesterol (CHO) in food matrices able to work in an aqueous media was synthesized. The proposed MISPE protocol could overcome the limitations of traditional detection methods, which require pre-treatments of the samples, such as saponification, extraction with organic solvents, etc. The possibility to obtain selective recognition of CHO from food matrices in an aqueous mixture without hydrophobical non-specific interactions is the main advantage of these materials. Another important advantage of our procedure is the direct HPLC analysis of eluate without any treatment. In this study, three different MIPs, owing different hydrophilic characteristics were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. After the evaluation of the selectivity of the CHO imprinted polymers, the performance of these materials as Solid-Phase Extraction (SPE) sorbents was investigated. Good recoveries were obtained in the evaluation of the NIISPE-HPLC procedure, which can be successfully used for the determination of CHO in Calabrian pecorino cheese. (c) 2007 Elsevier Ltd. All rights reserved.