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.
- 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)