Detection of triazine herbicides in water, juice, and tea using deep eutectic solvent-based emulsive liquid–liquid microextraction combined with high-performance liquid chromatography†

This study developed a deep eutectic solvent-based emulsive liquid–liquid microextraction method combined with high-performance liquid chromatography (DES-ELLME-HPLC) for the detection of triazine herbicides. The technique was validated for food sample detection. Hydrophobic DES was prepared by using tributylphosphine oxide and octanoic acid to replace toxic solvents. In ELLME, the prepared DES was mixed with distilled water and then added to samples for emulsification. During the emulsion, triazine herbicides are transferred from the sample to the extractant. The limit of detection was 0.008 mg L⁻¹, while the extraction recoveries ranged between 84.8% and 102.0%, exhibiting relative standard deviations between 0.3 and 4.9%. This pre-treatment technique is simple, fast, and green and can be applied to water, juice, and tea samples. Compared with traditional ELLME, DES pre-treatment solves the singularity of the extractant selection and allows the technique to be applied to multiple pesticides.