Semi-automatic emulsification liquid-liquid microextraction with deep eutectic solvent for the determination of...

In this study, a rapid and simple semi-automatic emulsification liquid-liquid microextraction technique based on deep eutectic solvents was developed for determining strobilurin fungicides in food samples using high-performance liquid chromatography. Novel deep eutectic solvents formed as extractants by combining quaternary phosphates and fatty acids, eliminating the need for toxic solvents in liquid-phase microextraction. The extraction process was facilitated by an electric micropipette, which emulsified and injected the deep eutectic solvent-water mixture directly into the sample. The semi-automated approach enhanced extraction speed and efficiency while minimizing manual error. The sample and deep eutectic solvent mixture were emulsified immediately and separated within 15 min of standing. Only an electronic micropipette was used to achieve extraction and separation. The method demonstrated a linear range of 2-200 μg L^-1 with R² > 0.996 and a limit of detection of 0.6 μg L^-1. Recovery ranged from 73.0 % to 100.1 %, with relative standard deviations from 0.4 % to 6.1 %. The greenness of the method was validated through multiple assessment tools, including the Green Analytical Procedure Index, Analytical GREEnness metric for sample preparation, and Sample Preparation Metric of Sustainability. The emulsification liquid-liquid microextraction procedure, based on innovative solvents and electric micropipette technology, proved successful for application in water, juice, and vinegar samples and showed potential for broader use in pesticide residue analysis in food.