Solid Eutectic Systems and Natural Deep Eutectic Solvents in Matrix Solid-Phase Dispersion for the extraction of phenolic compounds from lettuce samples

A new and revolutionary material, called, Solid Eutectic Systems (SES) based on natural compounds are presented, prepared, and characterized for the first time. Matrix Solid-Phase Dispersion (MSPD) was used to extract and preconcentrate five important phenolic compounds from Lactuca sativa. SES based on thymol and citric acid (TC 1:1) and a Natural Deep Eutectic Solvent (NADES) based on lactic acid, glucose, and water (LGH 5:1:8) were selected as the most effective sorbent and eluent, respectively. The variables that influence the MSPD parameters were optimized: 100 mg of dried lettuce, 400 mg of TC 1:1 sorbent, 30 s of grinding time, and 1430 μL of LGH 5:1:8, obtaining AGREE and AGREEprep scores of 0.90 and 0.72. Recoveries (%) of the phenolic compounds were 70 to 115 %, with a relative standard deviations lower than 12 %. Finally, the limits of detection and quantification were 1.7–2.2 µg g⁻¹ and 5.1–6.7 µg g⁻¹, respectively. SES marks a transformative milestone, providing eco-friendly solutions with a streamlined preparation process. The versatile sample preparation ensures efficient cleanup across various matrices. Enhanced simplicity and adaptability can result from intelligent sorbent development for improved selectivity and sensitivity. In this study, SES was introduced as a novel green sorbent for MSPD, efficiently extracting phenolic compounds from lettuces.