Dynamically coated silica monolith with ionic liquids for capillary electrochromatography

Abstract

An ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF 4 ]) was introduced as dynamic coating of a silica monolithic column for capillary electrochromatography of phenols and nucleoside monophosphates. The run-to-run and column-to-column repeatability of migration time for six phenols were satisfactory on this column with relative standard deviation values less than 0.90 and 4.31%, respectively. Anodic electroosmotic flow (EOF) was observed, which increased with the increase of [BMIM] [BF 4 ] on the monolith. Efficient separation of phenols and nucleoside monophosphates on this dynamically coated monolithic column was obtained, compared with a dynamically coated fused-silica column and unmodified silica monolithic column. The retention behavior of uncharged phenols is mainly manipulated by hydrophobic interactions due to the presence of butyl groups, and that of nucleoside monophosphates is governed by the electrostatic attraction mechanism based on the interaction between positively charged [BMIM] [BF 4 ] moieties and negatively charged phosphate groups. In addition, silica matrix also contributes to the separation resolution.

A novel ionic liquid-based monolithic column and its application in the efficient separation of proteins and small molecules by high-performance liquid chromatography

“…Organic polymer-based monoliths, on the other hand, can readily be post-modied and are stable over a wide pH range (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). 10 In particular, polymeric materials provide an excellent stationary phase in HPLC for the rapid separation of large molecules, such as proteins, nucleic acids and peptides.…”

“…Organic polymer-based monoliths, on the other hand, can readily be post-modied and are stable over a wide pH range (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). 10 In particular, polymeric materials provide an excellent stationary phase in HPLC for the rapid separation of large molecules, such as proteins, nucleic acids and peptides. 11 Nevertheless, they have a number of disadvantages, such as poor reproducibility and resolution, and they have a nonuniform structure due to inadequate solubility of the monomers and porogens.…”

Synthesis of ionic liquid‐bonded organic‐silica hybrid monolithic column for capillary electrochromatography

“…Although ILs have been broadly used as stationary phases in GC, HPLC, CE, only one paper reported their application in monolithic CEC. Tian et al 38 introduced 1‐butyl‐3‐methylimidazole tetrafluoroborate ([BMIM][BF 4 ]) as dynamic coating of a silica monolithic column to separate phenols and nucleoside monophosphates.…”

Recent advances in CE analysis of antibiotics and its use as chiral selectors

“…Finally, in the case of fluoroquinolones that are anphoteric, a micellar phase in the BGE is not required because these charged compounds can interact in a selective way with ionic liquids in an EKC mode. The interactions between ionic liquid‐cation and the analytes with opposite charge include electrostatic interactions, hydrophobic interactions and hydrogen bonding . Thus, Liu et al studied the influence of 1‐dodecyl‐3‐methyl‐imidazolium (C 12 MIM) basic ionic liquid on the separation of gatifloxacin, lomefloxacin, rufloxacin, and pazufloxacin antibiotics by EKC‐UV .…”