Departamento de Tecnología Química Ambiental, E.S.C.E.T, Universidad Rey Juan Carlos, C/ Tulipán s/n, 28933 Móstoles, Madrid, Spain.
Mikrochim Acta. 2019 Feb 6;186(3):164. doi: 10.1007/s00604-019-3267-2.
Hybrid mesostructured silicas with wormhole-like pore structure were synthesized and bi-functionalized with n-octyl (C8) and quaternary ammonium (NR) groups to obtain new sorbent materials for dispersive solid-phase extraction (dSPE) of polyphenols. Due to their nature of being both a reversed-phase and a strong anion-exchanger, the materials display mixed-mode retention mechanism. During the synthesis, the functionalization conditions were varied to obtain materials with different functionalization degree. The resulting materials (denoted as HMS-RPC8-SAX-1, HMS-RPC8-SAX-2 and HMS-RPC8-SAX-3) show high surface area, wormhole-like framework and controlled pore size. They were evaluated for multicomponent extraction of 22 polyphenols, including phenolic acids, flavonoids and stilbenes, from spiked juice samples. The sample extracts were analyzed by ultra-high performance liquid chromatography coupled to ion-trap tandem mass spectrometry. The adsorption capability, the amount of sorbent, the eluent and the elution volume were optimized. Best performance was achieved by using HMS-RPC8-SAX-2, which is the material with the highest fraction of NR groups. This material has a large extraction capability and provides high recovery values of the target analytes (70-101%) as a result of its hydrophobic and anion-exchange interactions. The detection limits for polyphenols in juice range from 1 to 560 ng mL. Graphical abstract Schematic presentation of dispersive solid-phase extraction of polyphenols from juice samples using a novel sorbent based on the bi-functionalization of mesostructured silica with n-octyl and quaternary ammonium groups, followed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) analysis. Due to the sorbent nature of being both a reversed-phase and strong anion-exchanger, the material displays mixed mode retention mechanism that improves its extraction capability.
具有蠕虫孔状孔结构的杂化介孔硅通过辛基（C8）和季铵（NR）基团的双功能化合成，得到了用于多酚分散固相萃取（dSPE）的新型吸附剂材料。由于其同时具有反相和强阴离子交换剂的性质，这些材料表现出混合保留机制。在合成过程中，改变功能化条件以获得具有不同功能化程度的材料。所得材料（表示为 HMS-RPC8-SAX-1、HMS-RPC8-SAX-2 和 HMS-RPC8-SAX-3）具有高表面积、蠕虫孔状骨架和受控的孔径。它们用于从加标果汁样品中多组分萃取 22 种多酚，包括酚酸、类黄酮和芪。通过超高效液相色谱-离子阱串联质谱法对样品提取物进行分析。优化了吸附能力、吸附剂用量、洗脱液和洗脱体积。使用具有最高 NR 基团分数的 HMS-RPC8-SAX-2 可获得最佳性能。该材料具有较大的萃取能力，并由于其疏水和阴离子交换相互作用，为目标分析物提供了高回收率（70-101%）。果汁中多酚的检测限范围为 1 至 560ng/mL。
