With the rapid development of the food industry and the growing concerns about food safety, it is particularly significant to develop fast, convenient and accurate techniques for food analysis and testing. In the analysis of food safety, due to the complex matrix composition and the low concentration of the target compounds, selecting the appropriate sample pretreatment method and extraction adsorbent is important for achieving good extraction efficiency. Two or more interactions of mixed-mode adsorbents with target compounds of the same type can occur simultaneously, and mixed-mode adsorbents can also interact with multiple target components with different properties simultaneously, resulting in increased adsorption selectivity and capacity compared to single-mode adsorbents. Hence, in this article, the classification, characteristics and application of mixed-mode adsorbents in the field of food analysis are reviewed with the purpose of providing a reference for researchers in the selection, preparation and application of mixed-mode adsorbents and of boosting the development of mixed-mode adsorbents in the field of food analysis.

In recent years, surface molecular imprinting technology has drawn a lot of attention for its application in sample pretreatment for food analysis. Due to the complexity of the food matrix, there are high requirements for the sensitivity and selectivity of food detection. Surface molecularly imprinted polymers are polymerized on the surface of a solid support, and when the template is removed, a cavity is formed to adsorb the target or its structural analogues. Various targets ranging from contaminants, toxicants and adulterants to natural active ingredients can be efficiently imprinted, thus making it easier to extract them from food matrices like dairy products, fruits and vegetables, meat products, and drinks. Owing to their potential to improve the selectivity and adsorption capacity and hence the accuracy of analysis, multi-template imprinting strategies and virtual template imprinting have become research hotspots. This article summarizes the design strategies, carrier types, preparation methods of surface molecularly imprinted polymers and reviews the progress made over the past five years in their application in sample pretreatment for food analysis in order to provide a reference for the application of surface molecularly imprinted technology in food analysis.