Alternative solvent systems for extraction and preconcentration of trace elements

Abstract

Alternative solvents have obtained increasing attention in the last years for sample preparation, since they can replace classical organic solvents that are considered highly toxic, volatile and flammable. The use of these solvents has contributed to develop simpler, miniaturized, inexpensive, and environmentally friendly methodologies for the determination of trace elements. Among them, ionic liquids and surfactants have been the most explored ones, while deep eutectic and switchable-hydrophilicity solvents have been gaining increasing attention in the last few years. In this review, relevant and useful physicochemical properties of these solvents along with the hybrid materials resulting from their combination with different nanomaterials are described. Thus, they are presented in this review as useful tools to develop efficient extraction techniques for sensitive and selective preconcentration of trace elements in samples of varied matrix composition. Trends and future developments related to the application of these solvents for analytical extraction are discussed.