Deep eutectic solvent applications in sample preparation of different analytes before gas and liquid chromatography instruments coupled with mass spectrometry and tandem mass spectrometry

Deep eutectic solvents (DESs) as new and green solvents, are formed by two or three components combined by hydrogen bond interactions to create a eutectic mixture with a melting point lower than the original components. The core focus of this review is on DES-based sample preparation methods considering microextraction methods performed prior to chromatographic techniques consisting of gas chromatography (GC) and liquid chromatography (LC) equipped with mass spectrometry (MS). Depending on the nature of DES, there are various ways to utilization of them in extraction procedures, including liquid- and solid-based extraction approaches. For the writing of the current paper, the main terms ‘‘DES’’, ‘‘extraction’’ and related terms were searched in Google Scholar, and all related articles were selected until 2023. An attempt has been made to present the field employing DESs in the extraction as having a backward-looking compilation. Fundamental recommendations were compiled to inform the future development of DES-based extraction approaches.