DETERMINATION OF H2O2 AND ORGANIC PEROXIDES IN CLOUDWATER AND RAINWATER ON THE KLEINER FELDBERG DURING FELDEX

This letter reports high-pressure liquid chromatography (HPLC) measure ments of H2O2 and organic hydroperoxides in cloud- and rain-water. :Ob servations were conducted on the Kleiner Feldberg (Germany) from late October to late November 1995, within the FELDEX-campaign. It was the first campaign ever in which organic peroxides were determined in clou d-water. H2O2 was found with concentrations of <0.008-3.19 mu mol . l( -1). Hydroxymethyl hydroperoxide (HOCH2OOH. HMHP) and l-hydroxyethyl h ydroperoxide (CH3CH(OH)OOH, 1-HEHP) were observed with concentrations in the range of <0.008-1.0 mu mol l(-1) (HMHP) and <0.008-0.28 mu mol( -1) (1-HEHP). The ratio of the sum of organic peroxides over the total amount of peroxides (H2O2-organic peroxides! was 0-81%. The concentra tions of S(IV) and H2O2 in the samples were anticorrelated. The result s indicate that organic peroxides, such as HMHP and 1-HEHP. should be included into modelling studies of the aqueous phase oxidation of S(IV ).