<p>Hydrogen (H) stable isotope analysis of specific plant organic compounds has become of interest as a tool for ecological, environmental and palaeoclimatological studies. Aside from the influence of leaf water evaporative enrichment on the &#948;<sup>2</sup>H composition of organic compounds, hydrogen isotope fractionation occurs during carbon metabolism in the plant (&#949;<sub>bio</sub>). To get a better understanding of the metabolic signal recorded in &#949;<sub>bio</sub>, we explored the variation of &#948;<sup>2</sup>H in cellulose and n-alkanes, and its relationship with phylogeny and other plant traits. Leaf material of a large set of species in the eudicot clade was collected in the botanical garden at the University of Basel, cellulose and n-alkanes were extracted, &#948;<sup>2</sup>H in both compounds and &#948;<sup>18</sup>O in cellulose were analysed. It was found that modelled leaf water differences only explain part of the observed variation of &#948;<sup>2</sup>H in organic compounds. &#948;<sup>2</sup>H appears to be related to phylogeny and a wider assessment of trait data is currently being undertaken to test for signal associations with physiological traits. This study helps address at which taxonomic level the variation of &#948;<sup>2</sup>H is found; illuminate plant physiological traits that can be responsible for shaping species specific &#948;<sup>2</sup>H values in organic compounds; as well as, provide novel insights into the &#948;<sup>2</sup>H covariation between cellulose and n-alkanes.</p>
Toward Improved Accuracy in Chlorine Isotope Analysis: Synthesis Routes for In-House Standards and Characterization via Complementary Mass Spectrometry Methods