Abstract
A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-nitrophenol, which can be quantified by measuring the absorption at 400 nm in neutral or basic media. The reactions proceed fast under basic conditions and complete in 2 minutes to at pH 11 and 80?C. The linear range for the colorimetric method extends beyond 1.0 to 40 µM H2O2, and the limit of detection is ~1.0 µM H2O2. This method offers a convenient and practical process for rapid determination of hydrogen peroxide in aqueous media. Compared to many other techniques in H2O2 detection, this process is a direct measurement of H2O2, and is relatively unaffected by the presence of various salts, metal ions and the chelator EDTA.
Highlights
Hydrogen peroxide is an integral part of atmospheric chemistry and biological systems
In the presence of redox active metal ions, H2O2 can be converted to OH· radicals via Fenton reactions [5]: FeII (CuI) + H2O2 → FeIII (CuII) + OH– + OH
After the addition of H2O2, the original absorption peak for 4-nitrophenylboronic acid pinacol ester (Figure 1) decreased intensity while a new peak centered at 405 nm appeared and increased in intensity with an isobestic point at 330 nm, and the color of the solution changed from colorless to yellow, implying the formation of 4-nitrophenol
Summary
Hydrogen peroxide is an integral part of atmospheric chemistry and biological systems. Hydrogen peroxide is exceptionally soluble in water and it is thought to be the most efficient oxidant in the formation of H2SO4 from dissolved SO2 [1]. This implies that hydrogen peroxide could have some role in the acidity of rainwater. H2O2 is produced in reactions catalyzed by numerous bio-enzymes. It has come forth as a recently recognized messenger in cellular signal transduction [3]. In the presence of redox active metal ions, H2O2 can be converted to OH· radicals via Fenton reactions [5]: FeII (CuI) + H2O2 → FeIII (CuII) + OH– + OH
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call