A disposable and ready-to-use liquid-filled stick microextraction method for the efficient extraction and determination of triazole fungicide residues in tea beverages and herbal extracts

This study presents a novel liquid-filled stick microextraction (LFSME) method for the efficient extraction of hydrophobic compounds from aqueous samples. The LFSME device, inspired by a single-use swab, consists of a hollow plastic stick pre-filled with a hydrophobic deep eutectic solvent (DES), and wrapped with polypropylene fabric at the end. Upon activation, the DES is released and absorbed by the polypropylene fabric, enabling direct immersion into the sample solution for efficient extraction. The extracted analytes are subsequently desorbed with acetonitrile and analyzed by liquid chromatography-ultraviolet detection. The method demonstrated excellent analytical performance, including high enrichment factors (34–90), good linearity (R 2 > 0.99), and low limits of detection (LODs: 0.99–2.61 ng/mL) for the five target triazole pesticides. The disposable and portable nature of the LFSME device eliminates the need for complex sample handling, providing a cost-effective and user-friendly solution for routine monitoring of pesticide residues and other contaminants in complex matrices.