Studying the mixtures formed by molecular machines within cells, or the mixtures found in a groundwater plume demands powerful instruments. Scientists are using one of the world’s most powerful 21-Tesla Fourier transform ion cyclotron resonance mass spectrometers (21T FTICR MS) to get answers. The instrument is at EMSL, the Environmental Molecular Sciences Laboratory, a U.S. Department of Energy Office of Science user facility. Two studies show the potential of the instrument. In one study, EMSL scientists created more than 8,000 molecular formula assignments from dissolved organic matter mixtures. In another, scientists rapidly identified and discovered new types of metal-binding molecules called siderophores, made by bacterial cells.