Utilization of wolfberry biomass waste-derived biochar as an efficient solid-phase extraction material for antibiotic detection in aquatic products

Antibiotic use in aquaculture leads residues in aquatic products, contributing to antimicrobial resistance and potential human toxicity. Complex sample matrices hinder detection. This study uses wolfberry biomass waste-derived biochar as a novel solid-phase extraction (SPE) sorbent to detect 26 antibiotic residues (14 fluoroquinolones, 12 sulfonamides) in aquatic products, effectively repurposing agricultural waste into a high-performance, eco-friendly material. The mesoporous structure of the biochar enables rapid diffusion of antibiotics into its interior, facilitating highly efficient adsorption. Adsorption kinetics follow a pseudo-first-order model, reaching equilibrium in 60 min. The superior adsorption performance enables the prepared biochar to serve as an SPE sorbent for drug residue analysis with stable performance over at least three reuse cycles. The SPE was used for real samples analysis based on HPLC-HRMS, and the detection limits was 1–4.5 μg·kg −1 , recoveries was 75–119 %. Validation against the national standard GB 31658.17–2021 confirms method practicality and reliability.