Determination of malachite green in fish based on magnetic molecularly imprinted polymer extraction followed by electrochemiluminescence

A novel procedure for selective extraction of malachite green (MG) from fish samples was set up by using magnetic molecularly imprinted polymers (MMIP) as the solid phase extraction material followed by electrochemiluminescence (ECL) determination. MMIP was prepared by using Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. MMIP was characterized by SEM, TEM, FT-IR, VSM and XRD. Leucomalachite green (LMG) was oxidized in situ to MG by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). And then MMIP was successfully used to selectively enrich MG from fish samples. Adsorbed MG was desorbed and determined by ECL. Under the optimal conditions, calibration curve was good linear in the range of 0.29–290μg/kg and the limit of detection (LOD) was 7.3ng/kg (S/N=3). The recoveries of MMIP extraction were 77.1–101.2%. In addition, MMIP could be regenerated. To the best of our knowledge, MMIP coupling with ECL quenching of Ru(bpy)32+/TPA for the determination of MG has not yet been developed. Fe3O4 magnetite as magnetic component, MG as template molecule, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, MMIP was prepared by bulk polymerization. And then MMIP was successfully used to selectively enrich MG from fish samples. The adsorbed MG was desorbed and determined by ECL. [Display omitted] •MMIP was first used to selectively enrich malachite green (MG) from fish samples.•This is the first paper combining MMIP with ECL for trace MG determination.•The limit of detection (LOD) of this method was 7.3ng/kg (S/N=3).