Covalent anionic copolymer coatings with tunable electroosmotic flow for optimization of capillary electrophoretic separations. Issue 20 (6th September 2022)

• Record Type: Journal Article
• Authors: Šolínová, Veronika; Tůma, Petr; Butnariu, Maria; Kašička, Václav; Koval, Dušan
• Other Names: Ren Carolyn guestEditor.
• Is Part Of: Electrophoresis. Volume 43:Issue 20(2022)
• Page Start: 1953
• Page End: 1962
• Publication Date: 2022-09-06
• Subjects: chiral separation -- electroosmotic flow -- helicene -- permanent capillary coating -- polyacrylamide; Electrophoresis -- Periodicals; Electrophoresis -- Periodicals; 541.372
• DOI: 10.1002/elps.202200130
• Languages: English
• ISSNs: 0173-0835

Abstract

Abstract: We present a method for finely adjustable electroosmotic flow (EOF) velocity in cathodic direction for the optimization of separations in capillary electrophoresis. To this end, we use surface modification of the separation fused silica capillary by the covalently attached copolymer of acrylamide (AM) and 2‐acrylamido‐2‐methyl‐1‐propanesulfonate (AMPS), that is, poly(AM‐ co ‐AMPS) or PAMAMPS. Coatings were formed by the in‐capillary polymerization of a mixture of the neutral AM and anionic AMPS monomers premixed in various ratios in order to control the charge density of the copolymer. EOF mobility varies in the 0 to ∼40 × 10 −9 m 2 V −1 s −1 interval for PAMAMPS coatings ranging from 0 to 60 mol.% of charged AMPS monomer. For EOF in PAMAMPS‐treated capillaries, we observed (i) a negligible dependence on pH in the 2–10 interval, (ii) a minor variance among background electrolytes (BGEs) in function of their components and (iii) its standard decrease with increasing ionic strength of the BGE. Interest in variable cathodic EOF was demonstrated by the amelioration of separation of two kinds of isomeric anionic analytes, that is, monosaccharides phosphates and helquat enantiomers, in counter‐EOF mode.