Method of Extractive Freezing-Out: Twenty Years of Development

This review considers the outcomes of two decades of the development of the technique of extractive freezing-out. The method introduces a novel extraction principle based on the low-temperature separation of the target analytes through the redistribution of the solutes between the liquid phase of a pre-added, nonfreezing hydrophilic solvent and the solid phase of ice formed during the freezing process. A significant advancement of the method resulted from the implementation of extractive freezing-out under centrifugal force conditions (EFC). The introduction of EFC as a sample preparation step into numerous protocols for the determination of organic compounds has enabled the successful application of the method to chemical toxicological analysis, food quality control, environmental monitoring, and hydrochemical investigations. The technique demonstrates clear advantages over conventional liquid–liquid extraction, headspace analysis, and solid-phase extraction. The immediate prospects for the further development of the method are noted.