Junling He,Yong Tang,Chiliang Lin,Shaoyun Peng,Stig Pedersen-Bjergaard,Frederik André Hansen,Chen Zhou
Effective monitoring of veterinary drug residues in food is essential for legislation compliance and food safety, yet remains challenging due to low concentrations and complex matrices. This study introduced a miniaturized 96-well electromembrane extraction (EME) technique for pre-concentration and isolation 80 prohibited/restricted veterinary drugs from honey samples. Three liquid membranes were developed and characterized: V 1 (“V” for veterinary), a mixture of 2-undecanone and 0.5 % 2-nitro-p-cymene, was optimal for extraction of quinolones, tetracyclines, and β -agonists. V2, a mixture of 2-nitrophenyl octyl ether and a deep eutectic solution (formed upon mixing 6-methylcoumarin with thymol in a 1:1 w /w ratio) in a 1:1 v /v ratio, with the addition of 0.5 % di(2-ethylhexyl) phosphate (DEHP), was suitable for macrolides and sulfonamides extraction. V3, a deep eutectic solvent formed upon 1-decanoic acid and camphor in a 1:1 w /w ratio with 1 % DEHP, was suitable for aminoglycosides and β -lactams. Operational parameters were fine-tuned to achieve optimal extraction efficiencies, with recoveries ranging from 20.1–117.5 %, 20.3–91.9 %, and 20.1–118.8 % for V1, V2, and V3, respectively. High precision was observed for compounds with recoveries over 40 % (intra-day: 0.4–27.7 %; inter-day: 2.6–33.0 %), and matrix effects were generally within 80–120 %. This work established a theoretical framework for EME in food analysis, highlighting its potential as a powerful sample pretreatment method for the detection of veterinary drug residues. The results demonstrated the feasibility and advantages of using EME for ensuring food safety and regulatory compliance.
Coextraction of different groups of analytes is vital for saving sample volumes and simplifying analytical procedures in bioanalysis . Conventionally, coextraction was achieved by using multi-extraction systems with different supported liquid membranes (SLMs). However, the different membrane solvents tended to diffuse into the aqueous solutions and the other SLM to reach distribution equilibrium during extraction process, causing the system instability. In this work, a stable multi-extraction system (integration of liquid-phase microextraction and electromembrane extraction, LPME/EME) based on the identical supported semi-liquid membrane (SsLM) was developed. Principally, the state of distribution equilibrium of the membrane solvent (polypropylene glycol with molecular weight 4000) in SsLM could be reached at the beginning of extraction, which enhanced the coextraction stability. With this multi-extraction system, acidic and basic analytes were simultaneously extracted from practical biological samples. The extraction recoveries of the six model drugs in undiluted urine samples were over 70%. Followed by LC-MS/MS, the limits of quantification (LOQs) were in the range of 5–10 ng mL −1 . The multi-extraction system using the identical SsLM in this study shows promising potential in construction of other stable multi-extraction systems (e.g., LPME/LPME and EME/EME) in the future, which will greatly benefit the group separation of analytes in complicated biological samples.