Development of an online analyzer of atmospheric H2O2 and several organic hydroperoxides for field campaigns

An online automated instrument was developed for atmospheric measurements of hydroperoxides with separation and quantification of H₂O₂ and several organic hydroperoxides. Samples were trapped in aqueous solutions in a scrubbing glass coil. Analyses were performed on an HPLC column followed by para-hydroxyphenylacetic acid (POPHA) acetic acid and peroxidase derivatization and fluorescence detection. Analytical and sampling tests were performed on different parameters to obtain optimum signal-to-noise ratios, high resolution and collection efficiencies higher than 95% for H₂O₂ and organic hydroperoxides. The obtained performances show large improvements compared to previous studies. The sampling and analytical devices can be coupled providing an online analyzer. The device was used during two field campaigns in the Marseilles area in June 2001 (offline analyzer) and in July 2002 (online analyzer) at rural sites at low and high altitudes, respectively, during the ESCOMPTE and BOND campaigns. During the ESCOMPTE campaign, H₂O₂ was detected occasionally, and no organic hydroperoxides was observed. During the BOND campaign, substantial amounts of H₂O₂ and 1−HEHP+MHP were often detected, and two other organic hydroperoxides were occasionally detected. These observations are discussed.