A Molecular Dynamics View on Hydrophilic Interaction Chromatography with Polar-Bonded Phases: Properties of the Water-Rich Layer at a Silica Surface Modified with Diol-Functionalized Alkyl Chains
A Molecular Dynamics View on Hydrophilic Interaction Chromatography with Polar-Bonded Phases: Properties of the Water-Rich Layer at a Silica Surface Modified with Diol-Functionalized Alkyl Chains
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DOI：
10.1021/acs.jpcc.6b03799
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发表时间：
2016-06
影响因子：
3.7
通讯作者：
S. Melnikov;A. Höltzel;A. Seidel-Morgenstern;U. Tallarek
中科院分区：
文献类型：
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作者：
S. Melnikov;A. Höltzel;A. Seidel-Morgenstern;U. Tallarek
在亲水性相互作用色谱中，溶质保留在富水(W)层中，该层是在极性固定相与富乙腈（ACN）水流动相平衡后形成的。我们研究了富w层在极键相的性质，用平面二氧化硅表面模拟，分别以3.1 μmol/m2和4.4 μmol/m2的密度携带二醇功能化配体和残余OH基团。在含有30/70和2/98 (v/v) W/ACN的10 nm狭缝孔中进行的分子动力学模拟表明，直接吸附在二氧化硅表面的刚性单层W分子通过间隙性单层W分子连接，其中约0.8 nm厚的扩散W层与柔性链末端的极性基团相关。在弥漫性W层中，亲疏水元素大量分离。亲水性斑块是由W簇（氢键连接的W分子群）和二醇簇（通常由2-4个直接连接的二醇分子群）组成的。
In hydrophilic interaction chromatography solutes are retained in a water (W)-rich layer that forms upon equilibrating the polar stationary phase with an acetonitrile (ACN)-rich aqueous mobile phase. We study the properties of the W-rich layer at a polar-bonded phase, modeled by a planar silica surface carrying diol-functionalized ligands and residual OH groups at densities of 3.1 and 4.4 μmol/m2, respectively. Molecular dynamics simulations performed in a 10 nm slit pore containing between 30/70 and 2/98 (v/v) W/ACN show that a rigid, single layer of W molecules adsorbed directly at the silica surface is connected through an interstitial, single layer of W molecules with a ca. 0.8 nm thick diffuse W layer associated with the polar groups at the flexible chain ends. Hydrophilic and hydrophobic elements are largely segregated in the diffuse W layer. Hydrophilic patches are formed by W clusters (groups of hydrogen-bond-connected W molecules) and diol clusters (groups of typically 2–4 directly connected diol...