Microextraction by packed sorbents (MEPS): Fundamental principles and nanomaterial-based adsorbents

Sample preparation is a crucial aspect of analytical methods, particularly when dealing with complex matrices and/or low concentrations of analytes. Recent advancements in analytical methods have focused on minimizing sample preparation devices, evolving towards extraction techniques that utilize solvent-free or green solvents, or minimal amounts of solvents. Microextraction by Packed Sorbent (MEPS) is a miniaturized version of the conventional Solid-phase extraction (SPE) technique. The MEPS has been recognized as a modern technique in sample preparation due to the minimal use of solid adsorbent, organic solvent, and liquid sample. This innovative technique allows for the recovery of the adsorbents and contributes to sustainability. Furthermore, MEPS can be seamlessly integrated with chromatographic systems in an automated manner to enhance both efficiency and reproducibility. This review tries to have comprehensive insight into the various MEPS technique, advancements, and emerging trends with emphasis on the wide range of employed nanomaterials as adsorbents.