Chemical Transformations in Acid Rain. Volume 1. New Methodologies for Sampling and Analysis of Gas-Phase Peroxide

摘要

New methodologies for the sampling and analysis of gas-phase peroxides (H2O2 and organic peroxides) using (a) diffusion denuder tubes and (b) gas-to-liquid transfer with prior removal of ozone have been investigated. The purpose was to develop an interference-free method for determining H2O2 in ambient air. A denuder approach using ferrous (1,10-phenantholine)-coated tubes was unsuccessful; although H2O2 was removed in the approach, the capacity was low and ozone was also removed, possibly through surface decomposition to H2O2 and its radical precursors. Gaseous peroxide in compressed air streams could be collected in impingers without artifact formation from surface ozone decomposition if O3 was first removed by gasphase titration with nitric oxide.