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

Analyst. 2012 Dec 21;137(24):5860-5. doi: 10.1039/c2an35923e.

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.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capillary Electrochromatography / methods*
  • Electroosmosis
  • Gold / chemistry*
  • Hydrophobic and Hydrophilic Interactions
  • Ionic Liquids / chemistry*
  • Metal Nanoparticles / chemistry*
  • Organic Chemicals / chemistry
  • Organic Chemicals / isolation & purification
  • Silicon Dioxide / chemistry*

Substances

  • Ionic Liquids
  • Organic Chemicals
  • Gold
  • Silicon Dioxide