g-C3N4/Fe3O4 Nanocomposites as Adsorbents Analyzed by UPLC-MS/MS for Highly Sensitive Simultaneous Determination of 27 Mycotoxins in Maize: Aiming at Increasing Purification Efficiency and Reducing Time

According to known studies, numerous mycotoxins have been found simultaneously in foods and have a certain expansion toxicity, so the simultaneous detection of multiple mycotoxins is absolutely critical. In this article, multifunctional magnetic g-C3N4/Fe3O4 nanocomposites have been fabricated to employ as modified QuEChERS adsorbents. In addition, they were also used in conjunction with ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS), an accurate quantitative approach, to analyze 27 mycotoxins in maize. The improved method not only has a powerful adsorption effect on the complex matrix by g-C3N4/Fe3O4 but also enables magnetic separation from the sample solution. Experiments proved that this method can exhibit good linearity under the appropriate and optimal external environment (r2 ≥ 0.9954), high sensitivity (the threshold of detection limit is 0.0004–0.6226 μg kg–1, and the threshold of quantification limit is 0.0014–2.0753 μg kg–1), adequate recoveries (77.81–115.21%), and excellent repeatability (with a threshold of intraday precision of 1.5–10.8% and interday precision in the range of 2.9–12.5%). In practice this method has been used to evaluate a variety of mycotoxins in maize specimens, and certain actual outcomes have been achieved.