Further Experiments Comparing Direct Vapor Equilibration and Cryogenic Vacuum Distillation for Plant Water Stable Isotope Analysis

Recent work compared six plant water extraction approaches for hydrogen and oxygen stable isotope analysis. Previously it was believed that these ex- traction approaches would provide analytes whose δ2H and δ18O values were similar, but the authors found significant differences in the isotopic composition of the produced analytes. We report a short followup experiment to specially explore systematic differences between one form of cryogenic vacuum distillation (hereafter CVD-2 from, based on Koeniger et al.[2]), and direct vapour equilibration (DVE[3, 4]).