Isotope-Ratio Infrared Spectroscopy : a reliable tool for the investigation of plant-water sources?
Martín-Gómez, Paula (Universitat de Lleida)
Barbeta i Margarit, Adrià (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Voltes, Jordi (Universitat de Lleida)
Peñuelas, Josep (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)
Dennis, Kate (Picarro, Inc.)
Palacio Blasco, Sara (Instituto Pirenaico de Ecología)
Dawson, Todd E. (University of California)
Ferrio, Juan Pedro (Universitat de Lleida)

Data:	2015
Resum:	Stable isotopes are extensively used as tracers for the study of plant-water sources. Isotope-ratio infrared spectroscopy (IRIS) offers a cheaper alternative to isotope-ratio mass spectroscopy (IRMS), but its use in studying plant and soil water is limited by the spectral interference caused by organic contaminants. Here, we examine two approaches to cope with contaminated samples in IRIS: on-line oxidation of organic compounds (MCM) and post-processing correction. We assessed these methods compared to IRMS across 136 samples of xylem and soil water, and a set of ethanol- and methanol-water mixtures. A post-processing correction significantly improved IRIS accuracy in both natural samples and alcohol dilutions, being effective with concentrations up to 8% of ethanol and 0. 4% of methanol. MCM outperformed the post-processing correction in removing methanol interference, but did not effectively remove interference for high concentrations of ethanol. By using both approaches, IRIS can overcome with reasonable accuracy the analytical uncertainties associated with most organic contaminants found in soil and xylem water. We recommend the post-processing correction as the first choice for analysis of samples of unknown contamination. Nevertheless, MCM can be more effective for evaluating samples containing contaminants responsible for strong spectral interferences at low concentrations, such as methanol.
Ajuts:	Ministerio de Economía y Competitividad CGL2013-48074-P Ministerio de Economía y Competitividad AGL2012-40039-C02 Ministerio de Economía y Competitividad AGL2012-40151-C03 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-274 European Commission 610028
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Cavity ring-down spectroscopy (CRDS) ; δ18O ; δ2H ; Ecohydrology ; Isotope-ratio infrared spectroscopy (IRIS) ; Isotope-ratio mass spectroscopy (IRMS) ; Soil ; Xylem
Publicat a:	The new phytologist, Vol. 207, Issue 3, (August 2015) , p 914-927, ISSN 1469-8137

DOI: 10.1111/nph.13376

Post-print 35 p, 2.3 MB

El registre apareix a les col·leccions:
Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
Articles > Articles de recerca
Articles > Articles publicats