Shanghai Key Laboratory of New Drug Design, School of Pharmacy , East-China University of Science and Technology , Shanghai 200237 , China.
Department of Chemistry and Biochemistry , University of Texas at Arlington , Arlington , Texas 76019-0065 , United States.
Anal Chem. 2018 Aug 7;90(15):8750-8755. doi: 10.1021/acs.analchem.8b01796. Epub 2018 Jul 23.
Bleeding of hydrophilic interaction liquid chromatographic (HILIC) phases is a major problem. A hydrophobic silica surface exhibits low bleeding but does not behave as a HILIC phase. A hydrophilic coating, such as that of poly(vinyl alcohol) (PVA) on a hydrophobic particle should result in a low-bleed hydrophilic phase. However, a silica particle functionalized in a hydrophobic manner is not wetted by PVA and cannot be coated with it. Coating with PVA becomes possible if one region of the hydrophobic functionality is polar. We describe a low-bleed HILIC stationary phase, PVA-coated benzylthioethyl-silica. The benzyl groups shield the silica from water erosion, while the thiol group provides sufficient local polarity for PVA to wet the material. The new stationary phase demonstrated good chromatographic performance and typical HILIC retention behavior. The measured silica concentration in the effluent was ∼80-fold lower than that from a bare silica column. The new stationary phase exhibited a lower background level, lower background noise, and lower background drift under gradient conditions than benchmark commercial columns.
亲水作用色谱（HILIC）固定相的流失是一个主要问题。疏水硅胶表面的流失较低，但不能作为 HILIC 相。亲水涂层，如疏水颗粒上的聚乙烯醇（PVA），应该会导致低流失的亲水相。然而，疏水官能化的硅胶颗粒不会被 PVA 润湿，也无法用其进行涂层处理。如果疏水官能团的一个区域具有极性，则可以进行 PVA 涂层。我们描述了一种低流失的 HILIC 固定相，即 PVA 涂层的苄基硫乙基硅胶。苄基基团可以保护硅胶免受水侵蚀，而巯基基团则提供了足够的局部极性，使 PVA 能够润湿该材料。新的固定相表现出良好的色谱性能和典型的 HILIC 保留行为。测量到的流出物中的硅胶浓度比裸硅胶柱低约 80 倍。与基准商业柱相比，新的固定相在梯度条件下具有更低的背景水平、更低的背景噪声和更低的背景漂移。
