title: Electrophoretic mobilities of neutral analytes and electroosmotic flow markers in aqueous solutions of Hofmeister salts.
abstract: Small neutral organic compounds have traditionally the role of EOF markers in electrophoresis, as they are expected to have zero electrophoretic mobility in external electric fields. The BGE contains, however, ions that have unequal affinities to the neutral molecules, which in turn results in their mobilization. In this study we focused on two EOF markers-thiourea and DMSO, as well as on N-methyl acetamide (NMA) as a model of the peptide bond. By means of CE and all atom molecular dynamics simulations we explored mobilization of these neutral compounds in large set of Hofmeister salts. Employing a statistical mechanics approach, we were able to reproduce by simulations the experimental electrophoretic mobility coefficients. We also established the role of the chemical composition of marker and the BGE on the measured electrophoretic mobility coefficient. For NMA, we interpreted the results in terms of the relative affinities of cations versus anions to the peptide bond.
authors: Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Prague, Czech Republic.
authors: Tomáš
authors: T
authors: Křížek
authors: Anna
authors: A
authors: Kubíčková
authors: Jana
authors: J
authors: Hladílková
authors: Pavel
authors: P
authors: Coufal
authors: Jan
authors: J
authors: Heyda
authors: Pavel
authors: P
authors: Jungwirth
mesh_terms: D000081:Acetamides / Q000737:chemistry; D002586:Cesium / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000379:methods*; D008094:Lithium / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D009994:Osmolar Concentration; D012492:Salts; D012996:Solutions; D013890:Thiourea / Q000737:chemistry
chemical_list: D000081:Acetamides; D012492:Salts; D012996:Solutions; D002586:Cesium; D008094:Lithium; D013890:Thiourea; C018595:N-methylacetamide; D004121:Dimethyl Sulfoxide
keywords: EOF markers; Ion-specific effects; Ion-specific mobilization; Molecular dynamics simulations; Neutral analytes