Preservation methods for the isotopic composition of dissolved carbon species in non-ideal conditions.

Rationale: The stable carbon isotope compositions of dissolved inorganic carbon (δC) and dissolved organic carbon (δC) are readily affected by post-sampling microbial activity if not adequately preserved. Existing preservation methods require rapid chilling, analysis, and/or toxic chemicals, all challenging to use safely in the field and during remote field seasons. Therefore, a preservation method that is safe but also effective over a range of storage times is needed when sampling waters at very remote sites.