Berlin 2001 – scientific programme
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Q: Quantenoptik
Q 30: Poster: Laser in Medicine
Q 30.7: Poster
Friday, April 6, 2001, 12:30–15:00, AT2
Studying isoprene emission by plants with a photoacoustic spectrometer — •Michael Wolfertz1, Sven Arnold1, Wilhelm Boland2, and Frank Kühnemann1 — 1Institute for Applied Physics, Bonn University, Wegelerstr. 8, D-53115 Bonn — 2Max Planck Institute for Chemical Ecology, Carl-Zeiss-Promenade 10, D-07745 Jena
Isoprene (C5H8) is the most important biogenic non-methane hydrocarbon (NMHC) in the troposphere [1] and plays an important role in its chemistry. Understanding and quantifying the synthesis and emission by different plant species is thus of high interest. We use a photoacoustic spectrometer with a sealed-off CO2 laser to study the emission of isoprene by leaves of Eucalyptus globulus. The emission range of the 13CO2 laser coincides with the strongest absorption features of isoprene and allows to discriminate the main isotopomer from the doubly deuterated species C5H6 D2, which is synthesized by the plant upon feeding with deuterated precursors. The spectrometer has an isoprene sensitivity limit of a few ppb and allows for the first time to conduct isoprene labelling studies in real time. Here it is used to study the dynamics of the isoprene synthesis following changes in environmental conditions like temperature and light intensity. These data shall help to better understand the parameters determining the regulation of the isoprene synthesis.
[1] A. B. Guenther, J. Geophys. Res. 100, 8873 (1995)