Homogeneous Liquid-Liquid Microextraction as an Efficient Sample Preparation Procedure: A Narrative Review

Detecting highly small amounts of analytes in complex samples is becoming increasingly important in the areas like environmental monitoring, pharmaceutical quality control, food safety, and clinical diagnostics. The presence of interfering substances and the extremely low concentration of target analytes require efficient sample preparation methods before analysis. Traditional methods have been widely used, but they often involve large amounts of solvents, complicated procedures, and are not fully align with the principles of green analytical chemistry. In recent years, miniaturized sample preparation techniques were used in analytical chemistry by reducing solvent use, simplifying workflows, and improving sensitivity. Among them, homogeneous liquid-liquid microextraction has gained attention for its ability to create a uniform phase that later separates when triggered by the factors like salt addition, pH change, or temperature shift. Several versions type of homogeneous liquid-liquid microextraction have been developed, including salt-induced, sugaring-out, deep eutectic solvent-based, and switchable hydrophilicity solvent homogeneous liquid-liquid microextraction methods. In this study a review was presented considering principles, optimization methods, applications, and future prospects for homogeneous liquid-liquid microextraction.