Robust triazine-based COF membrane for efficient enrichment and ultrasensitive determination of veterinary antibiotics from complex animal-derived food.

The cost-effective pretreatment and ultrasensitive determination of multiple antibiotic residues from complex animal-derived food are imperative, yet cumbersome. Herein, a novel triazine-based covalent organic framework (TpTAPT) film was assembled and employed as the robust solid phase microextraction (SPME) membrane for efficient enrichment of veterinary antibiotics, including sulfonamides, fluoroquinolones, and macrolides. With multiple functional groups, distinct surface charge distribution and hydrophobicity, TpTAPT membrane demonstrated superior enrichment performance for representative antibiotics than commercial SPME fibers (6.1-213.1 times) and membranes (1.1-167.6 times), and exhibited excellent anti-interference capacity with recoveries of 80.6-110% in complex matrix. Therefore, it was integrated with LC-MS/MS to establish an ultrasensitive method for the trace analysis of antibiotics in milk and dried meat products, with detected concentration low to 5.7 ng/L, satisfactory recoveries (80.3-119.8%) and low RSDs < 9.4%. The developed TpTAPT membrane-SPME protocol provided a reliable and practical approach for veterinary antibiotic determination, highlighting its potential in food analysis.