# Deep eutectic solvent-Ferrofluid based single-step magnetic-assisted liquid-liquid microextraction for Pyrethroid residues determination in vegetable oils by GC–MS/MS

## TL;DR

A new magnetic-assisted extraction method using deep eutectic solvents efficiently detects pyrethroid residues in vegetable oils.

## Contribution

A novel deep eutectic solvent-ferrofluid material enables rapid and efficient extraction of pyrethroids in vegetable oils.

## Key findings

- The DES-FFs material achieved high sensitivity and precision for pyrethroid detection in vegetable oils.
- Small-sized Fe3O4 nanoparticles improved colloidal stability and enabled rapid phase separation (<10 seconds).
- Recoveries of pyrethroids ranged from 79.88% to 107.90% in both refined and crude vegetable oils.

## Abstract

A deep eutectic solvents-based ferrofluids (DES-FFs) material was prepared by combining small-sized Fe3O4 magnetic cores with a ternary choline chloride/sesamol/coumarin (1:3:1) DESs. The material was used for single-step magnetic-assisted liquid-liquid microextraction (MALLME) and determination of 15 pyrethroids (PYs) in vegetable oils by GC–MS/MS. The small-sized Fe3O4 material improved colloidal stability of DES-FFs and enabled rapid phase separation (<10 s). The DES-FFs might leverage enhanced π-π stacking interactions between sesamol/coumarin and PYs, and optimal hydrophilicity-polarity matching, which collectively contributed to the high extraction efficiency for PYs. Comprehensive characterization (HRTEM, XRD, FTIR, TGA, etc.) validated the material's structural integrity, thermal stability and magnetic property. The developed method demonstrated high sensitivity (LODs: 0.91–3.03 ng/mL; LOQs: 3.02–10.09 ng/mL), significantly reduced matrix effect, and good precision (RSD ≤6.92%) for 15 PYs in vegetable oils, with recoveries ranging from 79.88% to 107.90%. Determination of 15 PYs was successfully achieved in both refined and crude vegetable oils.

•A DES-FFs material was prepared by combining Fe3O4 magnetic cores with a ternary choline chloride/sesamol/coumarin-DES.•The material was used for single-step MALLME and determination of PYs in vegetable oils by GC–MS/MS.•High extraction efficiency of PYs using DES-FFs might be due to the enhanced π-π stacking interaction.•Small-sized magnetic nanoparticles improved the colloidal stability of DES-FFs and enabled rapid phase separation (< 10 s).

A DES-FFs material was prepared by combining Fe3O4 magnetic cores with a ternary choline chloride/sesamol/coumarin-DES.

The material was used for single-step MALLME and determination of PYs in vegetable oils by GC–MS/MS.

High extraction efficiency of PYs using DES-FFs might be due to the enhanced π-π stacking interaction.

Small-sized magnetic nanoparticles improved the colloidal stability of DES-FFs and enabled rapid phase separation (< 10 s).