Abstract: A rapid HPLC method was established for the determination of chloramphenicol based on packed-nanofiber solid phase extraction. Samples were added with HClO4 for protein precipitation. The centrifugal supernatant was collected, adjusted to pH 7 and directly loaded onto a packed-nanofiber solid phase extraction column; afterwards, 100 μL of methanol was used to elute the column and 20 μL of the pooled eluate was injected into an HPLC system. The mobile phased used was Na2HPO4-citirci acid buffer (1:2, V/V, pH 3.8) at a flow rate of 1.0 mL/min. The detection wavelength was set as 277 nm. Perchloric acid concentration, pH and ionic strength of centrifugal supernatant and eluent volume were optimized. Under optimized conditions, the linear quantification range of the HPLC method was 0.05–10 μg/mL. Average recovery rates of chloramphenicol from spiked blank milk samples across three spiking levels were in the range of 92.3%–105.3% with an intra-day assay RSD between 2.5% and 8.9% and an inter-day assay RSD of 11.7% (n = 5). This method was more simple and efficient and showed higher precision and recovery compared with C18 column extraction. Hence it can used to determine chloramphenicol residue in milk as a reliable, efficient and environment-friendly method.

Key words: pretreatment, chloramphenicol, nanofiber, milk, high performance liquid chromatography (HPLC)