Study On The Determination Of Trace H₂O₂ And Organic Peroxides

As the rapid development of world economy and the large of population, more and more contaminations are released in the air. The pollution of organic peroxides becomes more concerned among numerous contaminations. It is necessary to determine the H2O2 and organic peroxides in the air, and to compare the difference of applied analytic methods. There are very important in preventing air pollution, improving circumstance and keeping people's health.Using preconcentrated freezed method collect samples. Spectrophotometer was used to detect peroxides in environmental air. This way was adapted to detect H2O2 and hydrophilic organic peroxides in atmosphere. It was a simple and trusty way, which was conveniented for detecting H2O2 and hydrophilic organic peroxides in open air. But this way was unsuitable for detecting dialkyl organic peroxides which might be exist in some serious polluted indoor air.Using PBN as spin trap matter, we studied the feasibility of detect organic peroxides by spin trapping and electron paramagnetic resonance technique. Organic peroxides decomposed·OR radicals by photolytically or thermally which formed PBN-OR adduct. The bulk of different·OR radicals had infection of the dihedral angel of O-N-C-H of PBN-OR adduct which made the differences of hyperfine splitting constants and△Hpp. So, we could determine the nature of Organic peroxides by hyperfine splitting constants and△Hpp in the same detect condition without interference in theory. The bond energy of–O–O– and the space effect of·OR radicals had infection the formation of PBN-OR adduct which made the different spin concentration of different organic peroxides in the same detect condition. It had a good reaction selectivity of organic peroxides decomposed·OR radicals by thermally, other organic contamination had no disturbance. It better to decompose·OR radicals by thermally and detect them by spin trapping and electron paramagnetic resonance technique.Choose some plastic particles, macromolecule synthetic materials which might use organic peroxides as solicitation or additive to make the primary study .We got EPR signal in five materials, and the spectrum constants had the character of organic peroxides'spectrum constants. We judged that it might be organic peroxides in these materials. Fluorescence spectroscopy was used to validate the judgement.