English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Abstract. For the past two decades, the measurement of nitrous oxide (N2O)isotopocules – isotopically substituted molecules 14N15N16O, 15N14N16O and 14N14N18O of the main isotopic species 14N14N16O – has been a promising technique forunderstanding N2O production and consumption pathways. The coupling of non-cryogenic and tuneable light sources with different detection schemes, such as direct absorption quantum cascade laser absorption spectroscopy (QCLAS), cavity ring-down spectroscopy (CRDS) and off-axis integrated cavity output spectroscopy (OA-ICOS), has enabled the production ofcommercially available and field-deployable N2O isotopic analyzers. Incontrast to traditional isotope-ratio mass spectrometry (IRMS), theseinstruments are inherently selective for position-specific 15Nsubstitution and provide real-time data, with minimal or no samplepretreatment, which is highly attractive for process studies. Here, we compared the performance of N2O isotope laser spectrometers with the three most common detection schemes: OA-ICOS (N2OIA-30e-EP, ABB – Los Gatos Research Inc.), CRDS (G5131-i, Picarro Inc.) and QCLAS (dualQCLAS and preconcentration, trace gas extractor (TREX)-mini QCLAS, Aerodyne Research Inc.). Foreach instrument, the precision, drift and repeatability of N2O molefraction [N2O] and isotope data were tested. The analyzers were thencharacterized for their dependence on [N2O], gas matrix composition(O2, Ar) and spectral interferences caused by H2O, CO2, CH4 and CO to develop analyzer-specific correction functions.Subsequently, a simulated two-end-member mixing experiment was used tocompare the accuracy and repeatability of corrected and calibrated isotopemeasurements that could be acquired using the different laser spectrometers. Our results show that N2O isotope laser spectrometer performance isgoverned by an interplay between instrumental precision, drift, matrixeffects and spectral interferences. To retrieve compatible and accurateresults, it is necessary to include appropriate reference materialsfollowing the identical treatment (IT) principle during every measurement.Remaining differences between sample and reference gas compositions have tobe corrected by applying analyzer-specific correction algorithms. Thesematrix and trace gas correction equations vary considerably according toN2O mole fraction, complicating the procedure further. Thus,researchers should strive to minimize differences in composition betweensample and reference gases. In closing, we provide a calibration workflow to guide researchers in the operation of N2O isotope laser spectrometers in order to acquire accurate N2O isotope analyses. We anticipate thatthis workflow will assist in applications where matrix and trace gascompositions vary considerably (e.g., laboratory incubations, N2Oliberated from wastewater or groundwater), as well as extend to futureanalyzer models and instruments focusing on isotopic species of othermolecules.

N&lt;sub&gt;2&lt;/sub&gt;O isotopocule measurements using laser spectroscopy: analyzer characterization and intercomparison

N<sub>2</sub>O isotopocule measurements using laser spectroscopy: analyzer characterization and intercomparison