In environmental sciences, the organic and inorganic components of natural molecules have generally been considered separately. Yet it has become clear in recent decades that the organic-inorganic interface is critically important in biological systems: from the inorganic perspective, there are essential uses of metals in all life forms due to the unique chemical properties metal ions provide. For example, iron and manganese are essential in photosynthesis, copper, iron, and molybdenum are co-factors in multiple key nitrogen cycle reactions, and cobalt, zinc, and even cadmium are critical to carbon uptake and intracellular transformations. And from the organic perspective these metals are typically bound by a wide variety of organic molecules. This project will support the acquisition of a modern mass spectrometer system that contribute to a system capable of interrogating both the organic and inorganic chemical complexities. The instrumentation will contribute to understanding of ocean biogeochemical cycling through the analysis of large, coordinated sampling efforts such as GEOTRACES (including in the upcoming Antarctic GP17 expedition), AtlantEco, and other collaborative projects, measuring metal-ligands and microbial proteins across large regions of the oceans. The proposed instrumentation will also benefit researchers within the ocean science community through a variety of collaborative studies including an ongoing collaboration with a HBCU, as well as through the dissemination of novel organic-inorganic methods. Data produced by this mass spectrometer will be shared on public repositories and incorporated into the Ocean Protein Portal, a web resource that makes ‘omic data accessible to non-expert users used in both research and education activities including class-based research projects. <br/><br/>The hybrid instrument developed in this project will enable interdisciplinary inorganic-organic studies. Specifically, the acquired orbitrap mass spectrometry instrumentation will be coupled to an inorganic plasma mass spectrometer via a custom multidimensional chromatographic system allowing simultaneous characterization of complex organic molecules and their metal contents. The resulting instrumentation will enable advances in areas of metal-ligand and dissolved organic matter characterization, metalloproteomics, and metaproteomics and will enhance new collaborative research studies on marine bioinorganic chemistry in the ocean sciences. Knowledge gained in these areas will improve the understanding of controls on Earth’s biogeochemical cycles through the study of nutrient stress biomarkers, biogeochemically relevant (metallo)enzymes, and metal cycling and bioavailability.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.