Measurements of atmospheric hydroperoxides over a rural site in central Japan during summers using a helicopter

The concentrations of hydroperoxides (H2O2 and MHP), O3, SO2 and NOX* over Imizu City, Toyama Prefecture, Japan were measured during summers using a helicopter. The concentrations of hydroperoxides were analyzed by an HPLC system within 5-10 min after the sampling. The H2O2 concentration was lowest at the surface, and the highest concentration was detected at altitudes of 6000 and 8000 ft. The MHP was also higher in the high-altitude atmosphere. Significantly high concentrations of hydroperoxides were observed when air pollutants were transported from China. The concentration of H2O2 was higher than that of SO2 above 4000 ft where the potential capacity of SO2 oxidation in the aqueous phase is large. A helicopter is useful for measuring of hydroperoxides in the high-altitude atmosphere using an HPLC system in a laboratory.