Performance of monolithic silica capillary columns with increased phase ratios and small-sized domains
Performance of monolithic silica capillary columns with increased phase ratios and small-sized domains
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DOI：
10.1021/ac060770e
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发表时间：
2006-11-15
影响因子：
7.4
通讯作者：
Tanaka, Nobuo
中科院分区：
文献类型：
--
作者：
Hara, Takeshi;Kobayashi, Hiroshi;Tanaka, Nobuo
以四甲基氧基硅烷为原料制备了整体硅胶毛细管色谱柱，与之前的材料相比，具有更小的结构域和更高的相比，并对其性能进行了评价。整体硅柱的外部孔隙度为0.65 ~ 0.76，总孔隙度为0.92 ~ 0.95，化学改性后的整体硅柱在反相模式下具有更高的性能和保留系数。在80%乙腈中，对于保留系数为1和8mm /s的溶质，在2- 3mm /s的最佳线速度(u)下，具有最小域尺寸（约1.3 μ m的通孔和约0.9 μ m的硅骨架）的十八烷基硅化整体硅柱的板高小于5 μ m。由于渗透性与填充5 μ m颗粒的柱相似，整体硅柱能够获得与填充2- 2.5 μ m颗粒的颗粒柱相当的柱效率，并且在先前柱的“禁止区域”中表现出性能。当在20-40 MPa或更低的压降下需要15 000 - 30 000或更多的理论板时，整体柱的性能可以与颗粒填充柱的性能进行比较。与以前的单片硅柱相比，共连续结构的均匀性增加，加上小尺寸的结构域，有助于提高性能。
Monolithic silica capillary columns for HPLC were prepared from tetramethoxysilane to have smaller sized domains and increased phase ratios as compared to previous materials, and their performance was evaluated. The monolithic silica columns possessed an external porosity of 0.65-0.76 and a total porosity of 0.92-0.95 and showed considerably higher performance and greater retention factors in a reversed-phase mode after chemical modification than columns previously reported. An octadecylsilylated monolithic silica column with the smallest domain size (through-pores of similar to 1.3 mu m and silica skeletons of similar to 0.9 mu m) showed a plate height of less than 5 mu m at optimum linear velocities (u) of 2- 3 mm/s in 80% acetonitrile for a solute having retention factors of similar to 1, and similar to 7 mu m at u) 8 mm/s. With a permeability similar to that of a column packed with 5-mu m particles, the monolithic silica columns were able to attain column efficiencies comparable to that of particulate columns packed with 2- 2.5-mu m particles, and showed performance in the "forbidden region" for the previous columns. The performance of the monolithic column can be compared favorably with that of a particle-packed column when 15 00030 000 or more theoretical plates are desired at a pressure drop of 20-40 MPa or lower. The increased homogeneity of the co-continuous structures, in addition to the small-sized domains, contributed to the higher performance as compared to previous monolithic silica columns.