Processes controlling the concentration of hydroperoxides at Jungfraujoch Observatory, Switzerland

Abstract

Abstract. An automated, ground-based instrument was used to measure gas-phase hydroperoxides at the Jungfraujoch High Altitude Research Station as part of the Free Tropospheric EXperiment (FREETEX) during February/March 2003. A nebulising reflux concentrator sampled ambient air twice hourly, prior to on-site analysis by HPLC speciation, coupled with post-column peroxidase derivatisation and fluorescence detection. Hydrogen peroxide (H 2 O 2 ) concentrations reached up to 1330 pptv over the 13-day period with a mean of 183±233 pptv (± one standard deviation). Methyl hydroperoxide (CH 3 OOH) reached up to 379 pptv with a mean of 51±55 pptv. No other organic hydroperoxides were detected. The lack of an explicit diurnal cycle suggests that hydroperoxide concentrations are chiefly influenced by transport processes rather than local photochemistry at this mountainous site. There was some evidence that elevated concentrations of H 2 O 2 existed in air-masses originating from the south-west, suggesting higher concentrations of HO x due to more active photochemistry. Air which had been recently polluted exhibited low H 2 O 2 concentration due to a combination of suppression of HO 2 by NO x and deposition. The concentrations of H 2 O 2 sampled here are consistent with previous box modelling studies of hydroperoxides, except in periods influenced by the boundary layer, where agreement required a depositional sink.

Peroxyacetic acid in urban and rural atmosphere: concentration, feedback on PAN-NO<sub>x</sub> cycle and implication on radical chemistry

“…With regard to all samples, the mean (and standard deviation) concentrations during daytime (08:00-20:00 LT) were 40.7±32.8 pptv for Beijing-2006, 141 Mazhuang-2007. These values are higher than or comparable with those in previous measurements that PAA was occasionally detected with a level of 10-30 pptv (Walker et al, 2006) and accounted for less than 10% of total measured peroxides (Fels and Jundermann, 1993). Temporal profiles of PAA concentrations for the five campaigns are shown in Fig.…”

“…For the above reasons, many studies were focusing on developing reliable and commercial methods to detect its aqueous concentration (Davies and Deary, 1988;Pinkernell et al, 1996;Ruttinger and Radschuweit, 2000;Awad, et al, 2003), and to monitor its airborne concentration on a regular basis in workplace environments (Effkemann et al, 1999;Hecht et al, 2004;Henneken et al, 2006). However, field measurements of PAA are extremely sparse (Fels and Junkermann, 1993;Walker et al, 2006), and hence, the limited data restrain better understanding the role of PAA on atmospheric chemistry.…”

Atmospheric hydrogen peroxide and organic hydroperoxides during PRIDE-PRD'06, China: their concentration, formation mechanism and contribution to secondary aerosols

“…The basis of this method is to quantify the fluorescent dimer produced by the stoichiometric reaction of POPHA and hydroperoxides through catalysis (Gäb et al, 1985;Hellpointner and Gäb, 1989;Kurth et al, 1991;Lee et al, 1995;Sauer et al, 1996Sauer et al, , 1997Sauer et al, , 1999Sauer et al, , 2001Grossmann et al, 2003;François et al, 2005;Xu and Chen, 2005;Walker et al, 2006). The catalyst used in this study was Hemin (Xu and Chen, 2005;Chen et al, 2008).…”

“…Over the past two decades, the distribution and roles of H 2 O 2 and CH 3 OOH in the atmosphere have been investigated by various methods on land, onboard ship, and aboard aircraft (Hellpointner and Gäb, 1989;Hewitt and Kok, 1991;Das and Aneja, 1994;Fels and Junkermann, 1994;Watkins et al, 1995a, b;Staffelbach et al, 1996;Jackson and Hewitt, 1996;Sauer et al, 1997Sauer et al, , 2001Lee et al, 1993Lee et al, , 1995Lee et al, , 1997Lee et al, , 1998Lee et al, , 2000Lee et al, , 2008Morgan and Jackson, 2002;Grossmann et al, 2003;François et al, 2005;Walker et al, 2006;Kim et al, 2007). Although numerous field measurements of H 2 O 2 and organic peroxides have been made, most of them were done at 25 • -55 • N, including North America, Brazil, Europe, Greenland, South Africa, and the Atlantic and the northwestern and central tropical Pacific (Lee et al, 2000).…”

Identification of Organic Hydroperoxides and Peroxy Acids Using Atmospheric Pressure Chemical Ionization – Tandem Mass Spectrometry (APCI-MS/MS): Application to Secondary Organic Aerosol

“…There are two reasons for this: i) unavailability of the ROOH standards because of their thermally unstable nature (Bach et al, 1996), and ii) the lack of appropriate analytical techniques. So far, the analysis of ROOH in the condensed phase has mainly been done by means of chemical assays, such as the iodometric (Docherty et al, 2005;Banerjee and Budke, 1964), triphenylphosphine (Nakamura and Maeda, 1996), ferrous oxidation-10 xylenol orange (Wasylaschuk et al, 2007), and horseradish peroxidase approaches (Walker et al, 2006;Hong et al, 2008).…”