Analysis of Ion-association Equilibrium of Precipitable Dipicrylaminate Ion in Aqueous Solution by Capillary Zone Electrophoresis

• TAKAYANAGI Toshio

  Department of Life System, Institute of Technology and Science, The University of Tokushima

• OGURA Kinuyo

  Faculty of Engineering, The University of Tokushima

• YABUTANI Tomoki

  Department of Life System, Institute of Technology and Science, The University of Tokushima

Abstract

The ion-association equilibrium of the dipicrylaminate ion (DPA⁻) was investigated in an aqueous solution with alkali metal ions and with its 18-crown-6 ether complexes as pairing cations by capillary zone electrophoresis (CZE). Although DPA⁻ is precipitable with the pairing cations of K⁺ and Cs⁺ in a homogenous aqueous solution, a low concentration of DPA⁻ below its solubility suppressed the formation of the precipitates, and DPA⁻ was detected as a usual CZE signal. Changes in the electrophoretic mobility of DPA⁻ was analyzed for its ion-association equilibrium. The ion association constants determined were almost comparable among alkali metal ions, while the ion association constants were meaningfully large with a hydrophobic 18-crown-6 ether complex of K⁺. The CZE separation was also proved to be useful for the equilibrium analysis under precipitating conditions. It was suggested that the precipitable property of DPA⁻ with K⁺ and Cs⁺ could not be attributed to the ion-association process in an aqueous solution, but to the condensation process concerning the intermolecular CH···O bond in the precipitate crystals, as reported.

Journal

• Analytical Sciences

  Analytical Sciences 30 (9), 919-924, 2014

  The Japan Society for Analytical Chemistry

Keywords

• Dipicrylaminate ion
• alkali metal ions
• 18-crown-6 ether complexes
• ion-association equilibrium
• aqueous solution
• capillary zone electrophoresis

Details

• CRID: 1390001204260604416
• NII Article ID: 130004687419
• NII Book ID: AA10500785
• DOI: 10.2116/analsci.30.919
• COI: 1:STN:280:DC%2BC2M7gslKitw%3D%3D
• ISSN: 13482246
• ISSN: 09106340
• NDL BIB ID: 025775389
• PubMed: 25213821
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I025775389
• Web Site: https://link.springer.com/content/pdf/10.2116/analsci.30.919.pdf
• Web Site: https://link.springer.com/article/10.2116/analsci.30.919/fulltext.html
• Web Site: https://www.jstage.jst.go.jp/article/analsci/30/9/30_919/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed