A method and apparatus for compressing ions inside an ion mobility device is disclosed. Ions are introduced into the mobility device. The ions are subjected to a non-constant electric field to form a potential gradient along a portion of the device so that ions with similar mobilities bunch together into sharper peaks while maintaining separation between other ions. The potential gradient progressively increases or decreases along the length of the device.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government support under Contract DE-AC05-76RLO1830 awarded by the U.S. Department of Energy and Grant Nos. U24 CA1690019 and P41 GM103493 awarded by the National Institutes of Health. The Government has certain rights in the invention.