Analytical Sciences

Abstract − Analytical Sciences, 34(3), 383 (2018).

Determination of Sulfate Ion with 2-Aminoperimidine Hydrobromide Using an Optode Based on Tetrabromophenolphthalein Ethyl Ester Membrane
Takashi MASADOME and Hidekazu ISHIKAWA
Department of Applied Chemistry, Faculty of Engineering, Shibaura Institute of Technology, Toyosu, Koto, Tokyo 135-8548, Japan
An optode method for the determination of sulfate ion was developed. The optode membrane is 2-nitrophenyl octyl ether-plasticized poly(vinyl chloride) membrane containing tetrabromophenolphthalein ethyl ester. The method is based on formation of an ion associate between the excess of 2-aminoperimidine hydrobromide (Ap) and sulfate ion in the sample solution, and detection of the concentration of the remaining Ap ion by the optode. Under the optimal conditions, a good linear relationship was found to exist between the absorbance of the optode membrane, and concentrations of sulfate ion in a concentration range from 20 to 400 μM. The developed optode method was applied to the determination of sulfate ion in environmental water samples.