This folder contains direct infusion high resolution mass spectra (DI-HRMS) of dissolved organic matter (DOM), blank samples and in-house reference DOM material as mzML files. Data were recorded on an Orbitrap Elite at the Max Planck Institute for Biogeochemistry. DOM was extracted from groundwater collected at Hainich Critical Zone Exploratory within the Collaborative Research Centre AquaDiva between 2014 and 2022.