Application of pH-responsive poly(2-dimethyl-aminoethylmethacrylate)-block-poly(acrylic acid) coatings for the open-tubular capillary electrochromatographic analysis of acidic and basic compounds

Roshanak Sepehrifar, Reinhard I Boysen, Basil Danylec, Yuanzhong Yang, Kei Saito, Milton T W Hearn

Research output: Contribution to journalArticleResearchpeer-review

17 Citations (Scopus)


A new type of stimuli-responsive polymeric (SRP) coating has been prepared for use in open tubular capillary electrochromatography (OT-CEC), by grafting poly(2-dimethylaminoethylmethacrylate)-block-poly(acrylic acid) (PDMAEMA-b-PAA) as a Y-shaped block copolymer with two dissimilar chain compositions onto the inner walls of aminopropyl-modified silica capillaries. The grafting process introduced weakly charged functional groups from the PAA and PDMAEMA, enabling the generation of electroendosmotic flow with magnitude and direction adjustable by changing the pH of the running buffer electrolyte. This stimuli-responsive PDMAEMA-b-PAA block copolymer was found to provide excellent resolution of various acidic and basic compounds, leading to efficient analyte separation. When operated in the OT-CEC mode, separation selectivities could be readily manipulated via differential contributions from chromatographic and electrophoretic mechanisms, simply by changing the pH or the ionic strength of the running buffer electrolyte.

Original languageEnglish
Pages (from-to)117-125
Number of pages9
JournalAnalytica Chimica Acta
Publication statusPublished - 21 Apr 2016


  • Ionic strength effects
  • Open-tubular capillary electrochromatography
  • PH effects
  • PH-responsive polymers
  • Zwitterion properties

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