Optical sensing membrane based on tetrabromophenolphthalein ethyl ester for the determination of cationic surfactants

Takashi Masadome, Tetsuya Takahashi

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An optical sensing membrane for detection of cationic surfactants was developed. The optical sensing membrane is 2-nitrophenyl octyl ether-plasticized poly(vinyl chloride) membrane incorporating tetrabromophenolphthalein ethyl ester (TBPE). The response of the optical membrane to cationic surfactants was a result of extraction of cationic surfactant into the PVC membrane. The protonated TBPE deprotonates forming an ion associate with the extracted cationic surfactant; simultaneously, the deprotonation of the TBPE is accompanied by a spectral change. Namely, the extracted cationic surfactant changes color of the membrane from yellowish green to blue (absorption maximum: 622 nm). The optical membrane responds to cationic surfactants such as Zephiramine and cetyltrimethylammonium bromide in the concentration range from 1 μM to 100 μM.

Original languageEnglish
Pages (from-to)441-448
Number of pages8
JournalAnalytical Letters
Issue number3
Publication statusPublished - 2007 Feb



  • Cationic surfactants
  • Optical sensing membrane
  • Plasticized poly(vinyl chloride) membrane
  • Tetrabromophenolphthalein ethyl ester

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry

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