Hydrogel sorbent-based sample preparation processes as green alternatives for the extraction of organic contaminants followed by chromatographic analysis

In recent years, there has been a drive towards making pretreatment approaches more environmentally sustainable and eco-friendly, with the introduction of microextraction techniques, advanced materials, innovative solvents, automated setups, and technological advancements. In this context, there is a particular focus on the exploration and integration of new sorbents into microextraction techniques. Hydrogels, among the emerging materials, have garnered significant interest due to their unique features, including polymeric three-dimensional sorptive networks of hydrophilic chains, enhanced porosity, open-structure geometry, and valuable mechanical properties. They are amenable to various chemical modifications to acquire specific physicochemical properties and integrate advanced materials like carbon and magnetic nanoparticles, boosting their sorbent and application potential for diverse targets. Herein, the majority of demonstrated hydrogel-based sample preparation approaches for extracting organic analytes, coupled with liquid-chromatographic-(LC) or gas-chromatographic-(GC) methods, are presented, with a focus on the key role of the hydrogel and the environmentally-friendly characteristics of the methods.