Recent developments and applications of dispersive liquid–liquid microextraction (DLLME)

Many DLLME methods have been developed in recent years. DLLME is a novel microextraction technique with great potential in sample pretreatment. In most works, the intensive research on DLLME is concerned with the broadening of the range of used extraction solvents to increase the extraction capability of the method. In response, some interesting solutions based on viable substitutes have been published; these solutions involve the adoption of ionic liquids, methods based on the solidification of a floating organic drop, procedures utilizing special devices, the adjustment of the mixture density of the solvents with the use of an auxiliary solvent, and methods based on supramolecules, all of which are widely applicable to analytes and demonstrate economical or environmental benefits. In this review paper, DLLME with lower and higher density extraction solvents and its combination with other extraction techniques with exemplified applications is discussed.