Publication
Assessment of bias in carbon isotope composition of organic leaf matter due to pre‐analysis milling methods
Publisher:
Wiley
Date:
21-06-2021
DOI:
10.1002/RCM.9134
Abstract: Stable isotope analysis of leaf material has many applications including assessment of plant water‐use efficiency and palaeoclimatology. To facilitate interpretations of small shifts in the carbon isotope composition (δ 13 C) of leaves, accurate and repeatable results are required. Pre‐s le homogenisation is essential to ensure a representative s le is analysed, but can also introduce error. We investigate how different grinding methods (freezer‐milling and ball‐milling) affect the carbon content and δ 13 C of tree leaves from a wetland in Queensland, Australia, commenting on how increased temperature, s le contamination, s le loss or poor homogenisation may impact results. No alteration of leaf δ 13 C is observed due to different milling methods, although there may be a significant increase in %C of s les processed using ball‐milling. We suggest %C variability is possibly due to contamination from abraded plastic vials or insufficient homogenisation during ball‐milling, with no significant impact on δ 13 C. Overall, we suggest that intermittent ball‐milling may be the best solution to reduce costs, preparation time and use of liquid nitrogen, aiming to achieve complete homogenisation using the shortest possible duration of milling.