Liquid-liquid microextraction techniques based on in-situ formation/decomposition of deep eutectic solvents

Deep eutectic solvents (DESs) have lately gained attention as a viable green substitute for traditional ionic liquids (ILs) and hazardous organic solvents, due to their low toxicity, ease of synthesis procedures, low-cost, and high biodegradability. The DESs are introduced as a eutectic combination of two or more green components with a high capability to form hydrogen bonds. Following the emergence of DESs, their applications in numerous domains of analytical chemistry, particularly in various extraction approaches, are growing rapidly. The facile synthesis procedures of these solvents based on hydrogen bonding have permitted the development of a number of innovative liquid-liquid microextraction (LLME) strategies based on the in-situ formation or in-situ decomposition of these solvents. To offer up-to-date information in this field, this review is provided a summary of literature dealing with the LLME approaches based on the in-situ formation/decomposition of the DESs.