Online solid-phase extraction of glucoraphanin and sulforaphane from non-edible plants based on amino...

Glucoraphanin (GR) and sulforaphane (SFN) are sulfur-containing compounds with diverse medicinal applications. However, cruciferous vegetables are a single source of GR and SFN, which limits development and utilization in natural resources. Herein, amino acid covalent organic framework (COF-Cys) was synthesized via click reactions and employed as an adsorbent in online solid-phase extraction (online SPE) to determine GR and SFN in non-edible plant samples. The adsorption mechanism was analyzed using density functional theory, revealing that adsorption occurred via electrostatic interaction and hydrogen bonding. Under the optimum conditions, good linearity (4-2500 ng/mL; R² = 0.9922 and 0.9968) and lower limits of detection (1.0 ng/mL and 0.6 ng/mL) were observed. GR and SFN were found in 18 non-edible plant samples, and recoveries of spiked samples were 89.1-109.3% with RSD ≤ 6.9%. The COF-Cys-online SPE-UPLC-MS/MS approach displays great potential for application to detect GR and SFN in non-edible plants and provide valuable support for the development of functional products.