Electromembrane extraction (EME): fundamentals and applications

Abstract

Conventional sample preparation methods are commonly used to ensure the best analytical response of the method. However, these methods still include large solvent and sample consumption, and lengthy operation time, among other drawbacks, contributing to the unfriendly environmental status of such approaches. On the other hand, the miniaturization of such conventional methods can lead to procedures that use less or no volume of organic solvents as well as the automation of such methods resulting in less environmentally harmful methodologies. Electromembrane extraction (EME) is a miniaturized liquid phase extraction, that uses an electrical field to drive the analytes from the sample (donor phase) to an acceptor phase through a hydrophobic membrane containing a supported organic solvent on its porous membrane. Since its introduction, the technique has shown great potential in the preconcentration and clean-up of complex matrices, such as biological fluids and environmental analyses. However, the performance of the method includes many parameters and theoretical understanding to improve the analytical performance of the method. With the increasing number of studies reporting EME application for different matrices, this review has as its main goals to bring an overview of the fundamentals involved during the EME extraction, from the theoretical point-of-view to the current applications of these methods for the evaluation of different complex matrices. We believe that this overview of the fundamentals and current application of EME extraction can be used as a guide to inspire the development of new and advanced EME methods.