Quantification of Lambda (Λ) in multi-elemental compound-specific isotope analysis

Patrick Höhener (1) , Gwenael Imfeld (2)

1 LCE - Laboratoire Chimie de l'environnement
2 LHyGeS - Laboratoire d'Hydrologie et de Géochimie de Strasbourg

In multi-elemental compound-specific isotope analysis the lambda (Λ) value expresses the isotope shift of one element versus the isotope shift of a second element. In dual-isotope plots, the slope of the regression lines typical reveals the footprint of the underlying isotope effects allowing to distinguish degradation pathways of an organic contaminant molecule in the environment. While different conventions and fitting procedures are used in the literature to determine Λ, it remains unclear how they affect the magnitude of Λ. Here we generate synthetic data for benzene δ2H and δ13C with two enrichment factors εH and εC using the Rayleigh equation to examine how different conventions and linear fitting procedures yield distinct Λ

Mots clés: Stable isotopes; Pollution; Assessment; Bioremediation

Domaines: Ingénierie de l'environnement; Chimie analytique

Patrick Höhener, Gwenael Imfeld. Quantification of Lambda (Λ) in multi-elemental compound-specific isotope analysis. Chemosphere, 2021, 267, pp.129232. ⟨10.1016/j.chemosphere.2020.129232⟩. ⟨hal-03082804⟩