Preparation of Hybrid Monolithic Columns via 鈥淥ne-Pot鈥?Photoinitiated Thiol鈥揂crylate Polymerization for Retention-Independent Performance in Capillary Liquid Chromatography

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• 作者：Haiyang Zhang ; Junjie Ou ; Zhongshan Liu ; Hongwei Wang ; Yinmao Wei ; Hanfa Zou
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：September 1, 2015
• 年：2015
• 卷：87
• 期：17
• 页码：8789-8797
• 全文大小：403K
• ISSN：1520-6882

文摘

A novel 鈥渙ne-pot鈥?approach was developed for ultrarapid preparation of various hybrid monolithic columns in UV-transparent fused-silica capillaries via photoinitiated thiol鈥揳crylate polymerization of an acrylopropyl polyhedral oligomertic silsesquioxane (acryl-POSS) and a monothiol monomer (1-octadecanethiol or sodium 3-mercapto-1-propanesulfonate) within 5 min, in which the acrylate not only homopolymerizes, but also couples with the thiol. This unique combination of two types of free-radical reaction mechanisms offers a simple way to fabricate various acrylate-based hybrid monoliths. The physical characterization, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermal gravimetric analysis was performed. The results indicated that the monothiol monomers were successfully incorporated into acryl-POSS-based hybrid monoliths. The column efficiencies for alkylbenzenes on the C18-functionalized hybrid monolithic column reached to 60鈥?00鈥?3鈥?00 plates/m at the velocity of 0.33 mm/s in capillary liquid chromatography, which was far higher than that of previously reported POSS-based columns prepared via thermal-initiated free-radical polymerization without adding any thiol monomers. By plotting the plate height (H) of the alkylbenzenes versus the linear velocity (u) of the mobile phase, the results revealed a retention-independent efficient performance of small molecules in the isocratic elution. These results indicated that more homogeneous hybrid monoliths formed via photoinitiated thiol鈥揳crylate polymerization; particularly, the use of the multifunctional cross-linker possibly prevented the generation of gel-like micropores, reducing mass transfer resistance (C-term). Another sulfonate-containing hybrid monolithic column also exhibited hydrophobicity and ion-exchange mechanism, and the dynamic binding capacity was calculated as 71.1 ng/cm (75 渭m i.d.).