An enhanced technique for automated determination of 15N signatures of N2, (N2+N2O) and N2O in gas samples. (31st May 2013)

• Record Type: Journal Article
• Authors: Lewicka‐Szczebak, Dominika; Well, Reinhard; Giesemann, Anette; Rohe, Lena; Wolf, Ulrike
• Is Part Of: Rapid communications in mass spectrometry. Volume 27:Number 13(2013)
• Page Start: 1548
• Page End: 1558
• Publication Date: 2013-05-31
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.6605
• Languages: English
• ISSNs: 0951-4198

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="rcm6605-sec-0001" sec-type="section"> <title>RATIONALE</title> <p>An enhanced analytical approach for analyzing gaseous products from <sup>15</sup>N‐enriched pools has been developed. This technique can be used to quantify nitrous oxide (N<sub>2</sub>O) and dinitrogen (N<sub>2</sub>) fluxes from denitrification. It can also help in distinguishing different N<sub>2</sub>‐ and N<sub>2</sub>O‐forming processes, such as denitrification, nitrification, anaerobic ammonium oxidation or co‐denitrification.</p> </sec> <sec id="rcm6605-sec-0002" sec-type="section"> <title>METHODS</title> <p>The measurement instrumentation was based on a commercially available automatic preparation system allowing collection and separation of gaseous samples. The sample transfer paths, valves, liquid nitrogen traps, gas chromatography column and open split of the original system were modified. A reduction oven (Cu) was added in order to eliminate oxygen and measure N<sub>2</sub>O‐N as N<sub>2</sub>. Gases leaving the separation system entered an isotope ratio mass spectrometer where masses <sup>28</sup>N<sub>2</sub>, <sup>29</sup>N<sub>2</sub> and <sup>30</sup>N<sub>2</sub> were measured.</p> </sec> <sec id="rcm6605-sec-0003" sec-type="section"> <title>RESULTS</title> <p>The enhanced technique enabled rapid simultaneous measurement of stable isotope ratios <sup>29</sup>N<sub>2</sub>/<sup>28</sup>N<sub>2</sub> and <sup>30</sup>N<sub>2</sub>/<sup>28</sup>N<sub>2</sub> originating from dinitrogen alone (N<sub>2</sub>) and from the sum of the denitrification products (N<sub>2</sub>+N<sub>2</sub>O) as well as the determination of <sup>15</sup>N enrichment in N<sub>2</sub>O. The <sup>15</sup>N fraction in the N pool undergoing N<sub>2</sub> and N<sub>2</sub>O production (<sup>15</sup><italic>X<sub>N</sub></italic>) and the contribution of N<sub>2</sub> and N<sub>2</sub>O originating from this pool (<italic>d</italic>) were determined with satisfactory accuracy of better than 3.3% and 2.9%, respectively.</p> </sec> <sec id="rcm6605-sec-0004" sec-type="section"> <title>CONCLUSIONS</title> <p>The precision and accuracy of this method were comparable with or better than previously reported for similar measurements. The proposed method allows for the analysis of all quantities within one run, thus reducing the measurement and sample preparation time as well as increasing the reliability of the results. Copyright © 2013 John Wiley & Sons, Ltd.</p> </sec> </abstract>