Preparation of zwitterionic covalent organic framework for high throughout extraction of fluoroquinolones from lake water and milk.

Abstract

A zwitterionic covalent organic framework was synthesized and applied as SPME blade coating for the extraction of fluoroquinolones in lake water and milk samples. The structure and functional groups of the sorbent were characterized via SEM, XPS, FT-IR, and XRD. Adsorption kinetic/isotherm analyses demonstrated chemisorption-driven monolayer adsorption with high affinity. Under the optimal SPME conditions, a high-throughput extraction method was established by incorporating zwitterionic covalent organic framework-coated blades into a 24-well plate system, which was subsequently coupled with LC-MS/MS for analysis. The proposed method exhibited good linearity (0.01-10 ng mL-1, R2 ≥ 0.9938), achieving LODs of 0.1-2.5 pg mL-1 in lake water and 0.2-2.8 pg mL-1 in milk, while recoveries were in the range of 72.3 %-124.7 % with RSD < 10.3 %. This approach provides an effective strategy for monitoring trace fluoroquinolones in environmental and food matrices, showcasing the potential of DBS-EB-COF-enhanced high-throughput SPME systems for applications in environmental and food safety surveillance.