Equilibrium Study on the Ion Association of Monovalent and Divalent Naphtholsulfonates with Tetrabutylammonium Ion in an Aqueous Solution by Capillary Zone Electrophoresis

Access this Article

Search this Article



The ion-association properties of monovalent and divalent naphtholsulfonate ions were investigated with tetrabutylammonium ion (TBA(+)) as a pairing ion in an aqueous solution. The ion-association constants were obtained by analyzing the change in the electrophoretic mobility of naphtholsulfonate ions in the presence of TBA+ by capillary zone electrophoresis; also, the contribution of a hydroxyl group to the ion associability of monovalent and divalent naphtholsulfonate ions, as well as the electrophoretic mobility of the ions, was investigated. The obtained ion-association constants indicate that the positional isomers possessing anionic groups at the β-position of the naphthalene ring are more associable with TBA(+) than those at the α-position, and that the ion associability of the divalent naphtholsulfonates is larger than those of the monovalent ones, except for 1-naphthol-2-sulfonate. The abnormal associability of 1-naphthol-2-sulfonate can be explained by a synergistic increase in the hydrophilicity of the divalent ion. The difference in the ion associability between the monovalent and divalent naphtholsulfonates, 0.16 in log unit on the average, was smaller than that between the naphthalenesulfonate and naphthalenedisulfonate ions, 0.30 log unit on the average. The electrophoretic mobility of the naphtholsulfonate ions obtained in the absence of TBA(+) is compared with each other, and the contribution of the hydroxyl group is discussed on the basis of the hydration behavior of the naphtholsulfonates.


  • Analytical Sciences  

    Analytical Sciences 14(2), 311-316, 1998-04-10 


References:  11

You must have a user ID to see the references.If you already have a user ID, please click "Login" to access the info.New users can click "Sign Up" to register for an user ID.


  • NII Article ID (NAID)
  • Text Lang
  • Article Type
  • ISSN
  • NDL Article ID
  • NDL Source Classification
  • NDL Call No.
  • Data Source
    CJP  NDL  IR 
Page Top