One-pot derivatization/magnetic solid-phase extraction coupled with liquid chromatography-fluorescence detection for the rapid determination of sulfonamide residues in honey

Abstract

Consuming foods with excess sulfonamide residues threatens human health, underscoring the importance of their detection in food. This study presents an innovative one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method for sulfonamides analysis. This approach integrates the derivatization and extraction steps into a single process. The sample solution, along with the derivatization reagent fluorescamine and the sorbent magnetic hydroxyl multi-walled carbon nanotubes, is mixed and vortexed for 3 min. This procedure simultaneously conducts derivatization and extraction, with easy phase separation using an external magnet. This streamlined sample preparation method is completed in only 5 min and, when combined with liquid chromatography-fluorescence detection (LC-FLD), demonstrates excellent linearity (R² > 0.99) and satisfactory detection limits (0.004-0.04 ng/g) for the quantification of nine sulfonamides in honey samples. The proposed OPD/MSPE-LC-FLD method is distinguished by its simplicity, rapidity, high sensitivity, and specificity, making it an outstanding advancement in the field of food safety analysis.

Keywords: Fe3O4/MWCNTs-OH; Honey; Liquid chromatography-fluorescence detection; One-pot derivatization/magnetic solid-phase extraction; Sulfonamides.

Fig. 1

The chemical structures of the sulfonamides studied.

Fig. 2

Schematic diagram of the OPD/MSPE procedure for SAs analysis.

Fig. 3

Characteristics of the sorbent: (A) magnetization curve of Fe₃O₄/MWCNTs-OH and (B) the solid–liquid separation of Fe₃O₄/MWCNTs-OH in different solvents under an applied magnetic field.

Fig. 4

The LC-FLD chromatogram of (A) SAs-free aqueous solution treated with OPD/MSPE, (B) SAs aqueous solution (20 ng/mL) treated with FSA derivatization only, and (C) SAs aqueous solution (20 ng/mL) treated with OPD/MSPE.