Borate-modified magnetic graphene oxide in enrichment and purification of cis-diols compound from natural extract

Black tartary buckwheat, rich in rutin, has been traditionally used for treating cardiovascular diseases, yet its efficient separation remains challenging. Herein, magnetic graphene oxide (MGO) was functionalized with 3-aminophenylboronic acid (APBA) via EDC/NHS coupling, forming MGO@APBA for selective rutin enrichment. Magnetic solid-phase extraction (MSPE) coupled with high-performance liquid chromatography (HPLC-UV) was employed for rutin analysis. Adsorption performances suggest Langmuir isotherm and pseudo-second-order model as best fit (Q_m = 80.18 mg g^-1). High satisfactory recovery (98.9 %-101.9 %), low limit of detection (0.5 mg L^-1), wide linearity range (20-200 mg L^-1) and good coefficient of determination (R² = 0.994) were found. MGO@APBA demonstrated excellent selectivity through significant statistical (p = 0.03<0.05), reusability (>80 % adsorption efficiency after four cycles). MGO@APBA showed excellent selectivity and reusability, making it a promising tool for rutin purification. This study provides a strategy for rutin separation and highlights the potential of borate-functionalized nanomaterials in natural product extraction.