Rapid microwave-assisted dispersive micro-solid phase extraction of mycotoxins in food using zirconia nanoparticles

Abstract

Mycotoxins are a group of secondary fungi metabolites present in foods that cause adverse effects in humans and animals. The objective of this study was to develop and validate a reliable and sensitive method to determine the presence of fumonisin B1, aflatoxin B1, ochratoxin B, T-2 toxin, ochratoxin A and zearalenone. A rapid, effective process, which involves microwave-assisted dispersive micro-solid phase extraction (MA-d-μ-SPE), has been proposed for the extraction and detection of 6 mycotoxins in peach seed, milk powder, corn flour and beer sample matrixes, for subsequent analysis by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Several experimental parameters (type of dispersant, concentration of dispersant, vortex time, type of desorption solvent and pH) affecting the extraction efficiency were systematically studied and optimized. The optimum extraction conditions involved immersing 2.5 μg/mL of nano zirconia (as dispersant) in a 5 mL sample solution. After 2 min of extraction by vigorous shaking, the target analytes were desorbed by 100 μL of chloroform at pH 4.5. The results indicated good linearity in the range of 0.0074-3.6 μg/mL (r ≥ 0.9982), low limits of detection (0.0036-0.033 μg/kg for solid samples and 0.0022-0.017 ng/mL for beer), acceptable reproducibility (relative standard deviation (RSD%) 2.08-2.76% for retention time and 3.51-4.59% for peak area, n = 3), and satisfactory spiked recoveries (84.27-104.96%) for studied mycotoxins in sample matrixes, which demonstrated that MA-d-μ-SPE coupled with UHPLC-Q-TOF/MS is a useful tool for analysis of multi-mycotoxin.

Keywords: Microwave-assisted dispersive micro-solid phase extraction; Mycotoxins; Nano zirconia; Quadrupole time-of-flight tandem mass spectrometry; Ultra-high-performance liquid chromatography.