Chitosan-based sorbents for the micro-solid-phase extraction of pesticides

The widespread use of pesticides and their hazardous impacts on humans and animals have made their detection and determination a critical issue. However, due to the low concentration of pesticides and the complexity of the entire sample, it is essential to use sample preparation approaches before determining pesticides. Among sample preparation approaches, micro-solid-phase extraction (µ-SPE), as a miniaturized extraction technique, has garnered much attention. This technique decreases the use of materials, reagents, and solvents. Additionally, µ-SPE applies micro- and/or nano-based sorbents and employs miniaturized extraction gadgets and devices. The attributes of µ-SPE, plus the concepts of green analytical chemistry, have encouraged analytical scientists to introduce and use green and environmentally friendly materials in µ-SPE techniques. Chitosan (CS) is a biocompatible, low- or negligible-toxic, environmentally friendly, and cost-effective material. Another valuable property of CS is its capability for modification and combination with different compounds. CS-based materials not only address the problems of traditional sorbents but also introduce new ones with excellent features such as high stability, high adsorption capacity, etc. These factors motivated us to assess the recent development in using CS-based sorbents for the µ-SPE of pesticides from 2016 to 2025. In this article, the properties of CS are illustrated. Different CS composites and the possible mechanisms for extracting pesticides are reviewed. Finally, the current trends and prospects related to using CS-based sorbents in the µ-SPE of pesticides are summarized. This review article investigates the properties and utilizations of CS-based materials as sorbents in µ-SPE, highlighting their potential to revolutionize pesticide determination.