Deep eutectic solvent-based dispersive liquid-liquid microextraction (DES-DLLME) of antimicrobial drug residues from bovine, caprine, and ovine kidneys detected by LC-MS/MS

Dispersive liquid-liquid microextraction based on natural deep eutectic solvents (DES-DLLME) was developed, optimised, and validated for extracting 42 antibiotic drug residues from bovine, caprine, and ovine kidney samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this DES-DLLME method, the extraction solvent utilised is a hydrophobic deep eutectic solvent, and the donor solvent employed is a hydrophilic deep eutectic solvent that simultaneously functions as a disperser solvent. Various parameters that impact the extraction efficiencies of antibiotic drug residues were optimised. These include the selection of pre-extraction solvent, donor solvent, and extraction solvent, along with the respective volumes of these solvents. Furthermore, the influence of re-extraction and centrifugation duration was evaluated. Validation was performed in compliance with Commission Implementing Regulation (EU) 2021/808, issued on 22 March 2021. The parameters for validation, such as the calibration function, matrix effect, decision limit (CCα), accuracy, and precision, were established. The analysis yielded coefficient of determination ( R ²) values that ranged from 0.9944 to 0.9999, utilising a matrix calibration curve that was spiked at 0, 0.5, 1.0, 1.5, and 2.0 times the maximum residue limit (MRL). The CCα values were found to be between 59.3 and 1 484.8 μg/kg, indicating a correlation with the MRL concentration levels. • DES-DLLME extraction method of 42 of antimicrobial drug residues from biological matrices. • The developed and validated extraction method is cheap, fast and green. • The DES-DLLME/LC-MS/MS method was used for analysis of 42 antimicrobial drug residues in real meat. • The method was evaluated for greenness using 3 analytical matrices.