Recent Advances in Sorbent- and Solvent-Based Sample Preparation Techniques for Antidepressant Analysis: Trends, Comparison, and Perspectives

Antidepressants are widely prescribed pharmaceuticals, making their reliable determination essential for therapeutic drug monitoring (TDM), forensic toxicology, and environmental surveillance. Since they exist at trace levels in biological and environmental matrices, sample preparation remains the critical step determining the sensitivity and reliability of the analysis. This review surveys sample preparation techniques for antidepressants published between 2021 and 2026. The methods are classified into sorbent- and solvent-based families, evaluated with respect to operating principles, analytical performance, applicability, and practical limitations. Across both categories, the dominant trends emphasize miniaturization, a shift from generic hydrophobic retention toward tailored molecular recognition, using molecularly imprinted polymers (MIPs), metal-organic frameworks (MOFs), and engineered nanomaterials, as well as the integration of green chemistry principles through deep eutectic solvents (DESs), switchable solvents (SSs), ionic liquids (ILs), and bio-based sorbents. A comparative assessment shows that extraction time is governed primarily by the mass-transfer mechanism rather than by the physical state of the extracting phase. Furthermore, while attainable sensitivity is strongly influenced by the detection system and preconcentration capability, the sample matrix remains a central criterion for method selection. Based on these findings, matrix-oriented guidance is provided to facilitate the rational selection of extraction strategies in antidepressant analysis.