Analysis of small air samples: {sup 15}N/{sup 14}N isotope ratios from N{sub 2}O

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:61943

Meinertz, J; Tegtmeyer, A R; Brand, W A ^[1]

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1. Finnigan MAT, Bremen (Germany)

Interest in atmospheric trace gases has been increasing ever since these gases were identified to be key factors in both global warming and the depletion of the ozone layer. In this context N{sub 2}O plays an important role because it is a contributing factor to both phenomena. By studying the characteristic nitrogen and oxygen isotope fractionations of N{sub 2}O producing processes, one is able to identify the sources for atmospheric N{sub 2}O. Gas isotope ratio mass spectrometry is the analytical method for this task. However, conventional isotope analysis has been difficult to several reasons: (1) The concentration of N{sub 2}O in air is very low (0.34 ppm); (2) N{sub 2}O has the same atomic mass unit as CO{sub 2}, whose concentration in the atmosphere is more than a factor of 1000 higher ({approx}360 ppm). In this paper, the authors present a method to measure nitrogen and oxygen isotope ratios of N{sub 2}O directly from ml-size samples of atmospheric air using a Finnigan MAT 252 mass spectrometer.

• OSTI ID: 61943
• Report Number(s): CONF-9405234--
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORING
GREENHOUSE GASES
ISOTOPE RATIO
MASS SPECTROSCOPY
NITROGEN 14
NITROGEN 15
NITROUS OXIDE
OZONE LAYER