My research consists of the continuing development of new theory, techniques, and analytical/biological/environmental applications of Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. We were the first to apply Fourier transform techniques to mass spectrometry, and more than 800 FT-ICR mass spectrometry systems based on our patents and papers have been bought or built worldwide. At our National NSF High-Field FT-ICR Mass Spectrometry Facility at the National High Magnetic Field Laboratory, we currently offer 9.4, 9.4, 14.5, and 21 tesla (highest magnetic field in the world for FT/ICR) instruments. Our instruments hold world records for broadband mass resolution and mass accuracy and attract hundreds of users and collaborators from all over the world. We continue to push the FT-ICR technique to its ultimate limits for mass resolution, mass range, and sensitivity. FT-ICR MS allows us to identify 100,000 components in a mixture without prior separation (GC, LC , gels), thereby changing the whole approach to mixture analysis. We are also developing new numerical and graphical methods to recognize patterns in the enormous volume of data made available by FT-ICR MS (up to 8 Mwords per spectrum). Finally, we monitor H/D exchange by mass spectrometry to identify surface-exposed residues in proteins and protein complexes.