A novel magnetic β-cyclodextrin modified graphene oxide adsorbent with high recognition capability for 5 plant growth...

β-Cyclodextrin (β-CD) modified magnetic graphene oxide material (Fe₃O₄@SiO₂/GO/β-CD), a novel magnetic sorbent for enrichment and purification of plant growth regulators (PGRs) in vegetables prior to gas chromatograph mass spectrometer (GC-MS) detection, was successfully fabricated. The novel magnetic sorbent geometrically fitted to selectively recognize and enrich PGR analytes especially containing aromatic structure. The selectivity experiment demonstrated the higher selectivity of Fe₃O₄@SiO₂/GO/β-CD toward 5 PGR compounds than that of Fe₃O₄@SiO₂/GO. Several parameters affecting extraction efficiency including the volume of extraction solvent, amount of adsorbent, extraction time, type and the volume of desorption solvent were optimized. Under the optimized condition, good linear relationships were obtained in the range of 1-100μg/kg with determination coefficients (R²) from 0.9983 to 0.9996. The limits of detection (LODs) of 5 PGRs were from 0.04 to 0.28μg/kg. The proposed method had good potential for the analysis of trace level of 5 PGRs in real vegetable samples.