In this study, a novel covalent organic framework material, Fe₃O₄@COF(OT-BDD), was synthesized using 2,3-dihydroxyterephthalaldehyde (BDD) and o-tolidine (OT). This material was applied in magnetic solid phase extraction (MSPE) coupled with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the efficient determination of four types of aflatoxins (AFs) in nut samples. The experimental results showed that the developed analytical method exhibited excellent linearity over the concentration range from 0.1 to 100 μg/kg, with determination coefficients (R²) exceeding 0.999. Recovery rates for spiked sample ranged from 86.1% to 104.2%, and intra- and inter-day precisions, expressed as relative standard deviations (RSDs), were less than 11.2%. The limits of detection (LODs) ranged from 0.05 to 0.12 μg/kg, and the limits of quantification (LOQs) ranged from 0.13 to 0.37 μg/kg. The COF material synthesized in this study exhibited strong adsorption capacity for AFs and enabled rapid, accurate, and sensitive detection of AFs in nut samples, effectively addressing the limitations of traditional methods in handling the complex matrix of nut-based food products.

This study established a new method using magnetic solid-phase extraction (MSPE) based on a novel magnetic molecularly imprinted polymer (Fe₃O₄@MIP) combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the rapid and sensitive determination of four aflatoxins (AFs) in peanuts and soy sauce. Using a surface grafting polymerization strategy, Fe₃O₄@MIP with selectivity for AFs was successfully prepared with 5,7-dimethoxycoumarin as a dummy template, methacrylic acid (MAA) as a functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. Subsequently, the MSPE extraction conditions were systematically optimized. The results showed that the developed method had good linearity within the concentration range of 0.02-100 μg/kg (R² > 0.9915), with spiked recoveries in the peanut matrix ranging from 87.63% to 103.58%. Both intra-day and inter-day precision (relative standard deviation (RSD)) were below 8.16%, and the limit of detection (LOD) was as low as 0.0069-0.011 μg/kg. The prepared Fe₃O₄@MIP exhibited excellent selectivity and reusability for AFs. The MSPE-UPLC-MS/MS method is simple to operate and highly sensitive, and can effectively overcome matrix interferences, providing a reliable solution for the rapid and accurate detection of trace AFs in complex foods, and holding significant application value in the field of food safety monitoring.

With the growing demand for food safety detection, traditional analytical methods face significant technical challenges, such as lengthy detection cycles and low efficiency, particularly when dealing with complex food matrices and large sample volumes. Ambient ionization mass spectrometry (AMS) has emerged as a cutting-edge rapid analytical tool, demonstrating remarkable advantages in food safety detection since it requires no or minimal sample preparation. Characterized by high analytical speed and efficiency, AMS has been successfully applied to the rapid detection of various hazardous substances in foods, including pesticide and veterinary drug residues, chemical contaminants, and toxins. Furthermore, ambient ionization mass spectrometry imaging (AMSI) provides spatial distribution information of chemical compounds on sample surfaces, offering a visual basis for in situ sampling. This review systematically outlines the development and classification of AMS, with a focus on the current status of its application in the field of food safety. Additionally, it delves into the latest advancements in AMSI. The aim of this article is to provide a theoretical foundation and technical guidance for the selection and application of AMS and AMSI in rapid food safety detection.

Food authenticity assessment and variety identification are crucial for ensuring food safety and protecting consumer rights. Traditional analytical techniques provide qualitative and quantitative information on target compounds, forming an essential technical foundation for quality control. With the increasing demand for comprehensive analysis, the spatial distribution of target compounds in foods has become a key focus in food research and quality evaluation. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI), with its wide detection range, high sensitivity, high spatial resolution, and label-free characteristics, enables in situ visualization of the spatial distribution of lipids, proteins, sugars, and other molecules in foods. This technology offers a new analytical dimension for food authenticity verification and variety assessment. This review systematically summarizes the innovative application of MALDI-MSI in food science, highlighting its advantages in authenticity discrimination, variety tracing, and quality monitoring through case studies on various food types, including fruits, vegetables, grains, oils, and substances with both medicinal and culinary uses. Finally, the potential of MALDI-MSI in enhancing food safety supervision is discussed, emphasizing its critical role in food safety evaluation.