Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

5-15-1997

Journal or Book Title

Analytical Chemistry

Volume

69

Issue

10

First Page

1925

Last Page

1930

DOI

10.1021/ac9611632

Abstract

3-Methylindole (skatole) is a component of animal waste and is, consequently, a primary component in odor problems arising in livestock management, notably swine production. The ability to probe and to exploit the interactions of 3-methylindole with micelles has important implications for monitoring and controlling odor problems. The effect of a surfactant (Brij-35) on the fluorescence properties of indole, 1-methylindole, and 3-methylindole in aqueous solutions is reported. Steady-state fluorescence spectra reveal a blue shift in the emission as the surfactant concentration is increased, while the absorption spectra are practically unaffected. Time-resolved fluorescence measurements reveal shorter average lifetimes for 3-methylindole (3-MI) as the Brij-35 concentration is increased. The fluorescence decay of 3-MI in water is described well by a single exponential, whereas, at the highest Brij-35 concentration, a triple exponential is necessary to describe the fluorescence decay. The contributions of each component in the fluorescence decay are used to determine the extent of 3-MI partitioning into the micelle phase. It is found that 93% of the 3-MI molecules partition into the micelle at the highest Brij-35 concentration used. The equilibrium constant for the association between the micelles and the 3-MI molecules is determined to be 2.6 × 104 M-1. In addition, the reduction of 3-MI in the vapor phase by addition of a dry surfactant, lecithin, is also demonstrated.

Comments

Reprinted (adapted) with permission from Analytical Chemistry 69 (1997): 1925, doi: 10.1021/ac9611632. Copyright 1997 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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