title: N-methyl-2-pyrrolidonium methyl sulfonate acidic ionic liquid as a new dynamic coating for separation of basic proteins by capillary electrophoresis.
abstract: A simple and economical CE method has been developed for the analysis of four model basic proteins by employing N-methyl-2-pyrrolidonium methyl sulfonate ionic liquid (IL) as the dynamic coating material based on the interaction of both between electrostatic attraction and hydrogen bond, and between the organic cations of IL and the inner surface of bare fused-silica capillary. The N-methyl-2-pyrrolidonium-based IL modified capillary not only generated a stable suppressed electroosmotic flow, but also effectively eliminated the wall adsorption of proteins. Several important parameters such as the IL concentration, pH values, and concentrations of the background electrolyte were optimized to improve the separation of basic proteins. Consequently, under the optimum separation conditions, a satisfied separation of basic proteins including lysozyme, cytochrome c, ribonuclease A, and α-chymotrypsinogen A with theoretical plates ranging from 2.09 × 10(5) to 4.48 × 10(5) plates/m had been accomplished within 15 min. The proposed method first illustrated the effect of hydrogen bond between coating material and inner capillary surface on the coating, which should be a new strategy to design and select more effective coating materials to form more stable coatings in CE.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine, Ministry of Education, Department of Chemistry, Wuhan University, Wuhan, P. R. China; Suzhou Institute of Wuhan University, Suzhou, P. R. China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Guo
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Chen
authors.forename: Xiao-Hai
authors.initials: XH
authors.lastname: Zhou
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Hua-Shan
authors.initials: HS
authors.lastname: Zhang
mesh_terms: D000328:Adult; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D057230:Limit of Detection; D016014:Linear Models; D008698:Mesylates / Q000737:chemistry*; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D011760:Pyrrolidinones / Q000737:chemistry*; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry; D055815:Young Adult
chemical_list: D052578:Ionic Liquids; D008698:Mesylates; D011506:Proteins; D011760:Pyrrolidinones; C045880:methanesulfonic acid; C038678:N-methylpyrrolidone
keywords: CE; Dynamic coating; Ionic liquid; Protein separation