Perspective: Hidden biases in isotope delta results and the need for comprehensive reporting

Measurements of stable-isotope composition on an isotope-delta scale can be subject to bias between laboratories or over time within a single laboratory. This bias can arise not just from differences in method protocol but also from changes in reporting guidelines, or even to the isotope-delta scales themselves. Without a clear description of method protocols, including all sample preparation steps, instrumental parameters and settings, data processing including calibration of results and estimation of measurement uncertainty, the traceability and comparability of isotope-delta values cannot be assured as bias(es) may remain hidden. To address this need, there are now clear guidelines published by IUPAC for reporting isotope-delta values for the light elements hydrogen, carbon, nitrogen, oxygen and sulfur.1 We recommend that authors and reviewers adhere to those guidelines when preparing and reviewing future publications.

Automated summary

Measurements of stable-isotope composition can be biased due to differences in laboratories or changes over time within a laboratory. To ensure traceability and comparability, clear method protocols and reporting guidelines are important. Therefore, authors and reviewers should adhere to IUPAC guidelines when preparing and reviewing publications.