Research Progress on Magnetic Solid Phase Extraction Based on Fe₃O₄ Magnetic Nanomaterials in Food Analysis

Pre-treatment of food samples is a crucial step in food analysis and testing. Due to the complex matrix and low levels of analytes in food samples, especially for the detection of trace compounds, it is particularly important to choose appropriate sample pre-treatment techniques. Through sample pre-treatment, target analytes can be effectively extracted before instrumental analysis, thereby improving the sensitivity and accuracy of detection. Magnetic solid phase extraction (MSPE) is a sample pre-treatment technique based on magnetic materials, using magnetic or magnetizable materials as adsorbents to quickly separate and enrich target analytes from samples in a magnetic field. Compared with traditional solid phase extraction, MSPE has advantages such as simple operation, environmental friendliness, short extraction time, less consumption of organic solvents, and easy separation between solid and liquid phases. This article presents a comprehensive overview of recent advancements and practical applications of MSPE technique in food analysis. It summarizes the methods used for the preparation and surface modification of magnetic adsorbing materials, and outlines the application of MSPE in detecting heavy metal residues, pesticide residues, veterinary drug residues, mycotoxins, illegal additives and other harmful substances in foods over the past five years (2020–2024). Furthermore, this review also analyzes the challenges faced by MSPE technique in the field of food testing, and discusses future development trends.