The invention generally relates to systems and methods for separating ions at about or above atmospheric pressure. In certain embodiments, the invention provides systems that include an ionization source that generates ions and an ion trap. The ion trap is maintained at about or above atmospheric pressure and includes a plurality of electrodes and at least one inlet configured to receive a gas flow and at least one outlet. The system is configured such that a combination of a gas flow and one or more electric fields produced by the electrodes separates the ions based on mass-to-charge ratio and sends the separated ions through the at least one outlet of the ion trap.