Study of beta-cyclodextrin/fluorinated trimethyl ammonium bromide surfactant inclusion complex by fluorinated surfactant ion selective electrode

Talanta. 2007 Nov 15;74(1):72-7. doi: 10.1016/j.talanta.2007.05.028. Epub 2007 May 24.

Abstract

The construction and performance of a liquid membrane electrode responsive to N-(1,1,2,2-tetrahydroperfluorooctyl)-N,N,N-trimethylammonium bromide (FTABr) and its use for the study of beta-cyclodextrin/fluorinated surfactant inclusion complex is described. The electrode is based on the use of tetrahydroperfluorooctyltrimethylammonium-tetraphenylborate ion pair as electro active material in polyvinyl chloride (PVC) matrix plasticized using 2-Nitrophenyl octyl ether (NPOE). The electrode exhibits a fast, stable, reproducible and "Nernstian" response (59+/-2 mV) for FTABr over the concentration range of 10(-5) to 2 x 10(-3) mol L(-1) at 298 K. The lowest detection limit is 2 x 10(-6) mol L(-1) and the response time is around 20-30s. The validity of the electrode, for detection of fluorinated surfactant ions and hence to carry out electrochemical measurements to study micellization of fluorinated surfactant, is verified by comparing the critical micelle concentration (cmc) value of FTABr obtained by using the electrode, with that obtained by surface tension measurements. Association constant K for beta-cyclodextrin/FTABr complex is evaluated from the potentiometric measurements carried out using this electrode and is observed to be approximately 1.26 x 10(5). The results suggest that beta-cyclodextrin forms an equimolar association complex with the FTA+ surfactant ion.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bromides / analysis*
  • Bromides / chemistry
  • Fluorine Compounds / analysis*
  • Fluorine Compounds / chemistry
  • Ion-Selective Electrodes*
  • Micelles
  • Quaternary Ammonium Compounds / analysis*
  • Quaternary Ammonium Compounds / chemistry
  • Surface-Active Agents / analysis*
  • Surface-Active Agents / chemistry
  • beta-Cyclodextrins / analysis*
  • beta-Cyclodextrins / chemistry

Substances

  • Bromides
  • Fluorine Compounds
  • Micelles
  • Quaternary Ammonium Compounds
  • Surface-Active Agents
  • beta-Cyclodextrins
  • betadex