Ultra-high performance liquid chromatography combined with mass spectrometry for determination of aflatoxins using dummy molecularly imprinted polymers deposited on silica-coated magnetic nanoparticles

• Published in: Mikrochimica acta (1966) 2016-04, Vol.183 (4), p.1469-1477
• Main Authors: Tan, Lei, He, Rong, Chen, Kuncai, Peng, Rongfei, Huang, Cong, Yang, Rong, Tang, Youwen
• Format: Article
• Language: English
• Subjects: Aflatoxins; Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography; Elution; High performance liquid chromatography; Imprinted polymers; Ionization; Ions; Magnetic separation; Mass spectrometry; Methacrylic acid; Microengineering; Nanochemistry; Nanoparticles; Nanotechnology; Original Paper; Polymer industry; Polymers; Scientific imaging; Silica; Silicon dioxide; Spectroscopy
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-016-1790-y

This article describes a method for determination of four aflatoxins by a combination of ultra-high performance liquid chromatography and mass spectrometry (UHPLC-MS/MS). Magnetic dummy molecularly imprinted polymers (md-MIPs) are used for fairly selective preconcentration. The preparation of the md-MIP involves (a) coating of magnetic nanoparticles (with a typical diameter of 200 nm) with a shell of silica, (b) modifying the surface with methacryloxy groups, and (c) creating a MIP on the surface by graft imprinting in aqueous solutions using 5,7-dimethoxycoumarin as the dummy template, and methacrylic acid and 4-vinylpyridine as the functional monomers. After elution of the template, the md-MIPs can be used for fairly selective extraction of the aflatoxins B1, B2, G1 and G2. Following magnetic separation of the particles, the aflatoxins were eluted and quantified by UHPLC-MS/MS. The limit of detection is 0.05 μg·kg −1 for aflatoxins B2 and G2, and 0.1 μg·kg −1 for aflatoxins B1 and G1. False-positive samples were identified by UHPLC-MS/MS in the positive ionization mode with multiple reaction monitoring. Graphical Abstract We describe a method for determination of four aflatoxins by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Determination of aflatoxins was accomplished by the magnetic dummy molecularly imprinted polymers, followed by a magnetic separation and subsequent quantification by UHPLC-MS/MS.