title: Preparation and evaluation of ionic liquid-gold nanoparticles functionalized silica monolithic column for capillary electrochromatography.
abstract: 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.
authors.affiliation: Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), College of Chemistry and Chemical Engineering of Guangxi Normal University, Guilin 541004, P. R. China.
authors.forename: Junyu
authors.initials: J
authors.lastname: Lu
authors.forename: Fanggui
authors.initials: F
authors.lastname: Ye
authors.forename: Aizhu
authors.initials: A
authors.lastname: Zhang
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Wei
authors.forename: Shulin
authors.initials: S
authors.lastname: Zhao
mesh_terms: D053801:Capillary Electrochromatography / Q000379:methods*; D053841:Electroosmosis; D006046:Gold / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D052578:Ionic Liquids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry / Q000302:isolation & purification; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D009930:Organic Chemicals; D006046:Gold; D012822:Silicon Dioxide