In recent years, several advanced methods have been developed which have allowed progress to be made, such as those using nuclear magnetic resonance (NMR) and highresolution mass spectrometry (HRMS), including tandem mass spectrometry (HRMS/MS) and coupling to ultra high-performance liquid chromatography (UPLC) . Complex but reliable reference materials are necessary in order to compare such methods, and critically to evaluate the scope and implications of the resulting datasets that are generated. Typically, materials from the International Humic Substances Society (IHSS) are used, which are longestablished, internationally known and trusted, and can be purchased on the scale of hundreds of milligrams. The main downside of these materials is that they are all sourced from terrestrial, often very brown water environments, with the exception of Pony Lake Fulvic Acid (PLFA) which came from an Antarctic lake with no higher order plants, but which has now been depleted with no plans to restock. The introduction of a marine reference material for dissolved organic carbon (DOC) concentration analysis has been very successful, and demonstrates demand for marine-specific reference materials , but is not available at sufficient concentrations or volumes as to be useful as a DOM characterisation standard. Thus, a suitable reference material for marine DOM studies does not currently exist.