The Measurement of an Environmentally Important Surfactant System Using Electrochemiluminescence

Date of Graduation

Summer 1999

Degree

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Committee Chair

Mark Richter

Abstract

Direct incorporation of fatty-amine ethoxylate surfactants (trade names Ethomeen T/15 and Ethomeen T/25) into an electrochemiluminescence (ECL) reaction sequence is reported. A linear relationship between ECL intensity and concentration of surfactants exist using Ru(bpy)₃²⁺ (bpy = 2,2'-bipyridine) as the light emitting molecule. Detection limits of 0.7ppm (mg/L) and 0.9ppm have been observed for Ethomeen T/15 in aqueous buffer and seawater, respectively. Detection limits of 1.1 ppm have been achieved for Ethomeen T/25. ECL intensity vs. electrochemical potential profiles show that emission occurs at potentials corresponding to oxidation of both Ethomeen and Ru(bpy)₃²⁺. The ECL emission is also pH dependent, with maximum intensities observed at pH 6-8. These results parallel those observed when tri-n-propylamine is substituted for EthomeenT/15 or T/25 and indicate a possible mechanism for ECL generation.

Subject Categories

Chemistry

Copyright

© Craig Joseph Alexander

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Dissertation/Thesis

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