A simple and economic solid-phase extraction method for purification of hesperidin from orange peel using a metal–organic framework-adsorbent (MIL-101 (Cr))

Orange peel is a rich source of nutrients and phytochemicals, widely used in medicines and foods. It contains flavonoids and antioxidants beneficial for health, including hesperidin (HES), a flavonoid abundant in citrus peels. This study used solid-phase extraction (SPE) and molecular spectrophotometry to extract and identify HES. The process is accurate, cost-effective, rapid, and environmentally friendly. HES was extracted using a hydroalcoholic method with MIL-101 (Cr), a metal-organic framework (MOF), as the adsorbent. MIL-101 (Cr) was prepared hydrothermally and characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). Experimental parameters such as sample concentration, adsorbent dosage, pH, and solvent type were optimized. HES was desorbed using acetonitrile, and absorption was measured at 285 nm. The limit of detection (LOD) and limit of quantification (LOQ) for HES were 0.145 and 0.530 μg mL^-1, respectively. The method exhibited good reproducibility with less than 2% RSD. This study successfully demonstrated the use of MIL-101 (Cr) in HES extraction, offering a rapid, specific, accurate, and cost-effective analysis method.