An Automated Instrument for Determining Atmospheric H2O2 and Organic Hydroperoxides by Stripping and HPLC
Simone Wiesufer, Axel Boddenberg, Axel P. Ligon, Guido Dallmann, Walter V. Turner and Siegmar Gäb*
Analytische Chemie, Bergische Universität Wuppertal, Gaußstraße 20, 42097 Wuppertal, Germany
* Corresponding author (gaeb@uni-wuppertal.de)
Abstract:
We describe the development and application of an automated instrument for determining hydrogen peroxide and organic hydroperoxides in air. The air is sampled continuously with a glass stripping coil, and the effluent from this coil is injected at intervals into an HPLC. H2O2 and the various organic hydroperoxides are separated on a reversed-phase column and detected by one of two post-column reaction systems: either the p-hydroxyphenyl acetic acid/horseradish peroxidase/fluorescence system or a system with Fe(II)/N,N-dimethyl-p-phenylenediamine/ VIS photometry. For the latter system, a compact and inexpensive detector was devised by combining a light-emitting diode with a liquid waveguide capillary cell and a channel photomultiplier. The detection limits with a 100-µL HPLC injection loop are the same for the two detectors: ca. 10 pptv for H2O2 and 20 pptv for methyl hydroperoxide (MHP). In October 2000 the instrument was tested in the FELDEX 2000 field campaign (Kleiner Feldberg, Taunus, Germany), which was intended to determine its reliability under prolonged usage. In July 2001 it was used for two weeks at Schneefernerhaus near the top of the Zugspitze, Germany’s highest mountain. In both tests it performed well.