Highly efficient analysis of fipronil and ethiprole in milk using ternary deep eutectic solvent-functionalized UiO-66-based tip-SPE − HPLC

In this study, for the effective determination of fipronil and ethiprole residues in milk, a new analytical approach, which was based on a tip solid-phase extraction (TSPE) by using a newly prepared ternary deep eutectic solvent-functionalized UiO-66 (TDES@UiO-66) as the adsorbent and HPLC-UV detection, was developed. The method integrated the advantages of both the high adsorption capability of the TDES@UiO-66 and the high efficiency of the TSPE, and enabled a rapid extraction of fipronil and ethiprole from milk samples within 8 min by utilizing only 3.0 mg of TDES@UiO-66 adsorbent. The developed method demonstrated an excellent analytical performance, including good linearity (linear rang: 0.02–10 μg/mL; r : 0.9990–0.9997), high precision (relative standard deviations: ≤ 9.9 %), good accuracy (recoveries: 91.1 %–109.8 %), and good sensitivity (limits of quantification: 0.011–0.018 μg/mL). This study provides a rapid and practical approach for the detection of fipronil and ethiprole in different milk samples.