No Cover Image

Journal article 238 views 36 downloads

A Modified Indigo Method for the Determination of Ozone in Nonaqueous Solvents / J. Nobbs; C. Tizaoui

Ozone: Science & Engineering, Volume: 36, Issue: 1, Pages: 110 - 120

Swansea University Author: Tizaoui, Chedly

DOI (Published version): 10.1080/01919512.2013.836956

Abstract

The indigo method for the analysis of aqueous ozone was modified to allow analysis of dissolved ozone in nonaqueous liquid phases. The method was tested using the solvent decamethylcyclopentasiloxane 245 and a vegetable oil. The molar absorptivity at 600 nm of the indigo trisulphonate molecule was r...

Full description

Published in: Ozone: Science & Engineering
Published: 2014
URI: https://cronfa.swan.ac.uk/Record/cronfa20190
Tags: Add Tag
No Tags, Be the first to tag this record!
Abstract: The indigo method for the analysis of aqueous ozone was modified to allow analysis of dissolved ozone in nonaqueous liquid phases. The method was tested using the solvent decamethylcyclopentasiloxane 245 and a vegetable oil. The molar absorptivity at 600 nm of the indigo trisulphonate molecule was re-checked and found to be 20,069 ± 412 L mol−1 cm−1 which is in agreement with the generally accepted value. Linear correlation between liquid phase and gas phase ozone concentrations confirmed that ozone solubility in decamethylcyclopentasiloxane 245 obeyed Henry's law with a constant of 1.71 ± 0.09 mg L−1 per mg L−1 in the gas phase. Ozone solubility in the vegetable oil followed a power law model with k = 0.148 and n = 0.767 (liquid and gas phase concentrations in mg L−1). The stoichiometry of the reaction between ozone in the nonaqueous phase and indigo trisulfonate in acidic solution was also confirmed as being about one. Moreover, the reaction products were confirmed by chromatographic analysis. This method was found effective to analyze ozone in nonaqueous solvents with a lower limit of detection of 2.6 μg L−1 and upper limit of detection of 142.7 mg L−1.
Keywords: Ozone, Indigo Method, Decamethylcyclopentasil-oxane, Vegetable Oil, Two-Phase Ozonation, Indigo Trisulfonate, Isatin-5-Sulfonic Acid, Isatin-Disulfonic Acid, Solvents Containing Ozone, Ozone-Loaded Solvent
College: College of Engineering
Issue: 1
Start Page: 110
End Page: 120