Determination of pyrethroid pesticides in medicine-food homology tea via homogeneous liquid-liquid microextraction coupled with high-performance liquid chromatography.

A green, rapid, and efficient homogeneous liquid-liquid microextraction technique involving the use of bio-based solvent 2-methyltetrahydrofuran was developed to extract deltamethrin, beta-cypermethrin, and bifenthrin from medicine-food homology tea samples, including mint-, ginger-, cinnamon- and chrysanthemum-based tea. Various solvents were screened via a conductor-like screening model, and three superior solvents were optimised and validated. 2-Methyltetrahydrofuran was selected as the extractant and added to the sample, and phase separation was induced with ammonium sulfate, achieving extraction in under 1 min without centrifugation. Mechanistic studies using density functional theory calculations and molecular docking revealed that van der Waals forces and hydrogen bonds dominate the interactions. The method exhibited excellent linearity within the range of 0.005-0.5 μg mL-1 and recoveries between 80.6 % and 109.8 %. The environmental sustainability of the entire process was verified. These results emphasise the methold's potential for applications in the trace analysis of pesticides in diverse food matrices.