▎ 摘　　要

In this work, magnetic graphene/mesoporous silica composites with carbon-functionalized pore-walls (denoted as MG@mSiO(2)-C composites) were synthesized and applied as restricted access matrix solid phase extraction (RAM-SPE) adsorbents for the determination of miglitol and voglibose in rat plasma by LC-MS/MS. The MG@mSiO(2)-C composites were synthesized by using the template (Cetyltrimethyl Ammonium Bromide, CTAB) as carbon source with sulfuric acid pretreated. The obtained nano-composites were proven to have many unique properties such as large specific surface area of 277.1 cm(2) g(-1), uniform mesopores with average pore size of 3.35 nm, and carbon-functionalized pore-walls. Taking advantage of the hydrophilic interaction between carbon and glycans, a-glucosidase inhibitors (miglitol and voglibose) could be directly extracted from rat plasma with no need of other pre-treatment procedures. The SPE conditions such as the adsorbent amount, elution solvent type, adsorption time and elution time were optimized. For both miglitol and voglibose, good linearities of 10-2000 ng mL(-1) were obtained with determination coefficients (R-2) > 0.99. The intra-day and inter-day RSDs were 3.3-6.9% (n = 6) and 6.0-8.0% (n = 6), respectively. The recoveries were in the range of 99.9-100.4% and the sensitivities were as low as 2-2.5 ng mL(-1) (LOD). This MG@mSiO(2)-C composites-based RAM-SPE method offers high extraction efficiency for the determination of a-glucosidase inhibitor in plasma.