Supramolecular Solvents (SUPRASs) in Green Sample Preparation

Abstract

Supramolecular solvents (SUPRASs) are water-immiscible nanostructured liquids composed of a 3D network of amphiphilic aggregates that maintain their structures via non-covalent interactions. These solvents are prepared from aquo/organic solutions of amphiphiles at concentrations above their critical aggregation concentration. Under these conditions, amphiphiles initially self-aggregate to form micelles or vesicles. Coacervation of these nano-aggregates into the 3D network of the SUPRAS is induced by different strategies, including variations in the composition of the initial mixture and modifications of temperature, pH, or ionic strength. SUPRASs are appealing alternative solvents in sample preparation. Thus, SUPRASs have several features (i.e., solvation capabilities, viscosity, chemical stability, and easy preparation) that favor their incorporation as extraction solvents in several microextraction methods. Besides, SUPRASs can be considered within the group of green and sustainable materials because they can be designed to present both low flammability and low vapor pressure, and can be prepared from natural, green, and cost-effective sources. This book chapter provides an overview of the use of SUPRASs in green sample preparation, including their utilization in all modes of liquid-phase microextraction (i.e., dispersive liquid–liquid microextraction, hollow fiber liquid-phase microextraction, and single-drop microextraction), solid-phase extraction (with special attention to magnetic solid-phase extraction), and solid–liquid microextraction.