15N Analysis of nitric oxide and nitrous oxide by cryotrap enrichment using a gas chromatograph quadrupole mass spectrometer and its application to 15N-tracer investigations of NO/N2O formation in soil
✍ Scribed by I. Sich; R. Russow
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 77 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0951-4198
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✦ Synopsis
Nitric oxide (NO) and nitrous oxide (N 2 O) are two important trace gases in the atmosphere. Determining the concentration and 15 N abundance of NO and N 2 O in air is difficult owing to their very low concentration in the atmosphere (NO `1 ppb(v); N 2 O % 0.32 ppm(v)). Although 15 N analysis of N 2 O in ambient concentrations can be carried out using a gas chromatograph quadrupole mass spectrometer system (GC-QMS) and a dosage of 2 mL of air by means of a sample loop, this system is not sensitive enough to measure the ambient concentration of NO and its 15 N abundance. Therefore the concentration of NO must be enriched by cryotrapping (cooling with liquid nitrogen). The 15 N analytical method developed enables the sensitive and sufficiently precise measurement of 15 N-enriched NO in air. Furthermore, the analytical equipment developed greatly improves existing 15 N 2 O analysis using the GC-QMS technique. An application of the 15 N analysis method will be shown for an investigation on the NO and N 2 O formation in black earth soil after 15 NH 4 , 15 NO 3 À and 15 NO 2 À labelling.