Miniaturization of self-assembled solid phase extraction based on graphene oxide/chitosan coupled with liquid chromatography for the determination of sulfonamide residues in egg and honey

• A novel miniaturization of self-assembled solid phase extraction was established.
• Graphene oxide/chitosan was an effective adsorbent for sulfonamides.
• The method detection limits were less than 0.98 ng g−1.
• The proposed method was applied for the analysis of sulfonamides in egg and honey.

The miniaturization of self-assembled solid phase extraction (m-SASPE) based on graphene oxide/chitosan (GO/CS) coupled with liquid chromatography-ultraviolet detection was developed for rapid screening of five sulfonamide residues in egg and honey. GO/CS was synthesized by solution blending method and characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Parameters that affected extraction efficiency including sample pH, amount of the GO/CS, elution solvent and rotation speed were optimized in detail. Under the optimal conditions, good linear relationships between the peak area and the concentrations of the analytes were obtained. The linear ranges were 0.01–10.00 μg g−1 with correlation coefficients (r) ≧ 0.9989. The method detection limits (MDLs) were in the range of 0.71–0.98 ng g−1. The relative standard deviations (RSDs) of intra- and inter-day analysis were less than 3.5 and 7.1%, respectively. The proposed method was successfully applied for the analysis of sulfonamide residues in egg and honey. The average recoveries for two samples spiked at levels from 0.02 to 2.0 μg g−1 were in the range of 75.3–105.2% with RSDs less than 13.5%.