INFLUENCE OF SUBSTRATE PARAMETERS ON COLUMN SELECTIVITY WITH ALKYL BONDED-PHASE SORBENTS
INFLUENCE OF SUBSTRATE PARAMETERS ON COLUMN SELECTIVITY WITH ALKYL BONDED-PHASE SORBENTS
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DOI：
10.1016/s0021-9673(00)96149-1
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发表时间：
1984-01-01
期刊：
影响因子：
--
通讯作者：
WISE, SA
中科院分区：
文献类型：
--
作者：
SANDER, LC;WISE, SA
研究了在不同二氧化硅衬底材料上制备的单体C18相和聚合物C18相的键合相性质的差异。在合成中使用了22种孔径在50-1000ä之间的二氧化硅。所得粘结相的相负荷范围为1.3mmol.m o l/m~2-5.4Mol/m~2。在结合之前测量了衬底的物理性质，包括表面积、孔体积、堆积密度和背景碳。在二氧化硅底物的性质和所得相的层析行为上观察到了很大的差异。在选择性和绝对保留率方面的差异是作为孔大小的函数观察到的，其中聚合物相的选择性变化最大。还考察了二氧化硅前处理对大孔和窄孔底物的相合成和柱选择性的影响。经酸处理的二氧化硅比碱处理的二氧化硅具有更强的聚合性。相负荷和柱选择性的变化被认为是二氧化硅表面反应性和孔径大小的函数。提出了一个聚合物相合成的模型，其中反应的程度受尺寸排斥机制的限制。
Differences in bonded-phase properties were studied for monomeric and polymeric C18phases prepared on a variety of silica substrate materials. A total of 22 silicas with pore diameters ranging from 50-1000 Å were used in syntheses. Phase loadings for the resulting bonded phases ranged from 1.3–5.4 μmol/m2. Physical properties of the substrates including surface area, pore volume, packing density, and background carbon were measured prior to bonding. Large differences were observed in the properties of the silica substrates and in the chromatographic behavior of the resulting phases. Differences in selectivity as well as absolute retention were observed as a function of pore size, with the greatest changes in selectivity occurring for the polymeric phases. The effect of silica pretreatment on phase synthesis and column selectivity was also examined for wide- and narrow-pore substrates. Phases prepared from silica pretreated with acid had greater polymeric character than those prepared from base-pretreated silica. Variation in phase loading and column selectivity is thought to be a function of both the reactivity of the silica surface and pore size. A model for polymeric phase synthesis is proposed where the extent of reaction is limited by a size-exclusion mechanism.