Preparation and evaluation of ionic liquid-gold nanoparticles functionalized silica monolithic column for capillary electrochromatography

• Published in: Analyst (London) 2012-12, Vol.137 (24), p.586-5865
• Main Authors: Lu, Junyu, Ye, Fanggui, Zhang, Aizhu, Chen, Xia, Wei, Yu, Zhao, Shulin
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Bonding; Capillarity; Capillary Electrochromatography - methods; Chemistry; Chromatographic methods and physical methods associated with chromatography; Electrochromatography; Electroosmosis; Exact sciences and technology; Gold - chemistry; Hydrophobic and Hydrophilic Interactions; Ionic Liquids - chemistry; Metal Nanoparticles - chemistry; Nanoparticles; Organic Chemicals - chemistry; Organic Chemicals - isolation & purification; Other chromatographic methods; Scanning electron microscopy; Separation; Silicon dioxide; Silicon Dioxide - chemistry
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c2an35923e

This paper describes the development of silica monolithic column modified with ionic liquids-gold nanoparticles (ILs-GNPs) for capillary electrochromatography (CEC). The novel ILs (1-methyl-2-mercapto-3-butylimidazolium bromide) were synthesized and used to modify GNPs functionalized silica monolithic column via the formation of a Au-S bond. The morphology of the GNPs and ILs-GNPs functionalized silica (ILs-GNPs-silica) monolithic column were characterized by transmission electron microscopy and scanning electron microscope, respectively. A cathodic electroosmotic flow was observed at pH above 6.4 on ILs-GNPs-silica monolithic column, which was reversed at acidic pH. The electrochromatographic performance of ILs-GNPs-silica monolithic column was evaluated by separation of different kinds of analytes such as hydrophobic, polar and basic compounds. The ILs-GNPs-silica monolithic column displayed enhanced hydrophobic retention characteristics in the separation of five hydrophobic n -alkylbenzenes when compared to the ILs bonded silica monolithic column. The column efficiencies for the n -alkylbenzenes were from 62 000 to 110 000 N m −1 . The ILs-GNPs-silica monolithic column exhibited reversed-phase electrochromatographic behavior toward neutral solutes. Separation of polar compounds was demonstrated on ILs-GNPs-silica monolithic column in reversed-phase CEC mode using high aqueous mobile phases. The relatively good peak shape and high separation efficiency on ILs-GNPs-silica monolithic column was obtained for basic solutes when compared to silica monolithic column modified GNPs. This paper describes the development of silica monolithic column modified with ionic liquids-gold nanoparticles for capillary electrochromatography.