Abstract: In this work, a novel reversed-phase/cation-exchange mixed-mode mesoporous silica adsorbent was synthesized as a SPE packing material and applied to the determination of six aminoglycosides (AGs) in milk byultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). MCM-41 was modified by 3-aminopropyltriethoxysilane, succinic acid glycoside and octadecyltrimethoxysilane. Structural characterization demonstrated that the synthesized material had a large specific surface area, uniform pore size, and functional group modification, exhibiting strong adsorption capacity and selectivity for AGs. The bifunctionalized synthetic material significantly improved matrix interference of milk compared to the carboxylated-only material. The proposed method exhibited a good linear correlation (0.992 7–0.999 5) for the six AGs in the concentration range of 5–500 ng/mL and obtained satisfactory recoveries (74.3%–107%) and relative standard deviation (2.6%–15.7%). The detection of limits (LODs) were 0.30–2.50 ng/mL. The material is low in cost, simple in fabrication and has good operability as a SPE package. It can be extended to the detection of AGs in other food or agricultural samples.

Key words: mesoporous materials, MCM-41, solid phase extract, aminoglycosides, ultra-high performance liquid chromatography-mass spectrometry, matrix effects, milk