Optical Sensing Membrane Based on Tetrabromophenolphthalein Ethyl Ester for the Determination of Cationic Surfactants

Abstract

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 mM to 100 mM.

Determination of Sulfate Ion with 2-Aminoperimidine Hydrobromide Using an Optode Based on Tetrabromophenolphthalein Ethyl Ester Membrane

“…The optode membrane based on TBPE was prepared as follows. 16,17 TBPE-K (0.056 g), NPOE (2.0 g) and 3 M HCl (10.0 mL) were stirred for 2 h. As a result, TBPE-H was extracted into the NPOE phase. After the NPOE phase and water phase were separated by centrifugation (10 min), the NPOE phase (1.5 g) and PVC powder (0.30 g) were dissolved in 7.5 mL of tetrahydrofuran (THF).…”

“…After the excess Ap is added to the sulfate ion in the sample, and precipitation of Ap-SO4 is formed, then the sulfate ion is determined by detecting the concentration of the remaining Ap ion. In the previous paper, 16,17 we reported an optode based on 2-nitrophenyl octyl ether-plasticized poly(vinyl chloride) (PVC) membrane incorporating tetrabromophenolphthalein ethyl ester (TBPE) for the determination of cationic surfactants. The optode is expected to respond to the Ap ion because Ap has a relatively hydrophobic property.…”

A New Microfluidic Polymer Chip with an Embedded Cationic Surfactant Ion-selective Optode as a Detector for the Determination of Cationic Surfactants

“…19 TBPE-K (0.0140 g), NPOE (1.0 g) and 3 M HCl (4.0 mL) were stirred for 4 h. As a result, TBPE-H was extracted into the NPOE phase. After the NPOE phase and the water phase were separated by centrifugation (5 min), the NPOE phase and PVC powder (0.40 g) were dissolved in 10 mL of tetrahydrofuran (THF).…”

“…11,12,[14][15][16][17] On the other hand, ion-selective optical sensor (Optode) membranes are suited for a detector of microfluidic chips, compared with the ISE and the ISFET. [18][19][20][21][22][23][24] From the viewpoints of applications to microfluidic technology, optodes are superior to ISEs because they are not subject to electrical noise, and no contacts to microfluidic chips are required for measurements. Furthermore, no reference electrode is needed for measurements using optodes.…”

Optical Sensor of Anionic Surfactants Using Solid-Phase Extraction with a Lactone-form Rhodamine B Membrane

“…[4][5][6][7][8][9][10] Hence, optical sensors have become very useful analytical tools. Several reports on optical sensors for the determination of surfactants have been published so far.…”