Details

Autor(en) / Beteiligte

• Subke, Jens‐Arne
• Toet, Sylvia
• D'Haese, David
• Crossman, Zoe
• Emberson, Lisa D.
• Barnes, Jeremy D.
• Ashmore, Mike R.
• Evershed, Richard P.
• Ineson, Phil

Titel

A new method for using 18 O to trace ozone deposition

Ist Teil von

• Rapid communications in mass spectrometry, 2009-04, Vol.23 (7), p.980-984

Erscheinungsjahr

2009

Quelle

Wiley Online Library All Journals

Beschreibungen/Notizen

• Abstract Isotopically labelled ozone ( 18 O 3 ) is an ideal tool to study the deposition of O 3 to plants and soil, but no studies have made use of it due to the technical difficulties in producing isotopically enriched ozone. For 18 O 3 to be used in fumigation experiments, it has to be purified and stored safely prior to fumigations, to ensure that the label is present predominantly in the form of O 3 , and to make efficient use of isotopically highly enriched oxygen. We present a simple apparatus that allows for the safe generation, purification, storage, and release of 18 O 3 . Following the purification and release of O 3 , about half (by volume) of the 18 O is present in the form of O 3 . This means that for a given release of 18 O 3 into the fumigation system, a roughly identical volume of 18 O 2 is released. However, the small volume of this concurrent 18 O 2 release (100 nmol mol −1 in our experiment) results in only a minor shift of the much larger atmospheric oxygen pool, with no detectable consequence for the isotopic enrichment of either soil or plant materials. We demonstrate here the feasibility of using 18 O as an isotopic tracer in O 3 fumigations by exposing dry soil to 100 nmol mol −1 18 O 3 for periods ranging from 1 to 11 h. The 18 O tracer accumulation in soil samples is measured using gas chromatography/isotope ratio mass spectrometry (GC/IRMS), and the results show a linear increase in 18 O/ 16 O isotope ratio over time, with significant differences detectable after 1 h of exposure. The apparatus is adapted for use with fumigation chambers sustaining flow rates of 1 m 3  min −1 for up to 12 h, but simple modifications now allow larger quantities of O 3 to be stored and continuously released (e.g. for use with open‐top chambers or FACE facilities). Copyright © 2009 John Wiley & Sons, Ltd.