Selective Extraction and Determination of Citrinin in Rye Samples by a Molecularly Imprinted Polymer (MIP) Using Reversible Addition Fragmentation Chain Transfer Precipitation Polymerization (RAFTPP) with High-Performance Liquid Chromatography (HPLC) Detection

Abstract

Citrinin (CIT) is a mycotoxin naturally in many foods that causes carcinogenic and mutagenic effects in the human body. A novel method was developed for the selective quantification of citrinin in rye samples. Citrinin-imprinted spheres were fabricated through reversible addition fragmentation chain transfer (RAFT) precipitation polymerization (RAFTPP) in the presence of 2-hydroxymethacrylate (HEMA, functional monomer), ethylene glycol dimethacrylate (EGDMA, cross-linker), citrinin (template), 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (CTA, RAFT agent), azobisisobutyronitrile (AIBN, initiator), and acetonitrile (ACN, porogen). The imprinted polymers were shown to be spherical with a high surface area and a porous structure. The rebinding properties of citrinin to the imprinted spheres were also examined in detail. The maximum adsorption capacity, equilibration time, and imprinting factor were 38.6 mg g−1, 90 min, and 3.89, respectively. In addition, the citrinin-imprinted spheres were regenerated at least 10 times without change in the adsorption capacity. The citrinin-imprinted particles were used to selectively remove and determine the analyte in rye extract. The calibration relationship was linear between 1 and 100 µg kg−1 with a limit of detection of 0.35 µg kg−1. The method also had high recoveries (98 to 100.0%) and low relative standard deviations (less than 4.1%). Therefore, the imprinted spheres are suitable for the selective determination of citrinin in rye extracts.