Patent ID: 8884217

Claim:
A system comprising: an ion source; a cell coupled to the ion source and configured to operate in at least three different modes comprising a collision mode, a reaction mode and a standard mode, the three different modes each configured to select analyte ions from a plurality of ions introduced into the cell from the ion source, the cell configured to couple to the ion source at an entrance aperture to permit introduction of the plurality of ions from the ion source into the cell, the cell further comprising a gas inlet configured to receive a substantially inert gas to pressurize the cell in a collision mode and to receive a reactive gas to pressurize the cell in a reaction mode, the pressurized cell further comprising an exit aperture configured to provide the analyte ions from the cell; a mass analyzer coupled to the cell; and a controller electrically coupled to the cell and configured to provide the substantially inert gas to pressurize the cell in the collision mode, configured to provide the reactive gas to pressurize the cell in the reaction mode, and configured to maintain the cell under vacuum in the standard mode, in which the controller is configured to provide an effective voltage from a voltage source to the cell in the collision mode to select ions comprising an energy greater than a barrier energy and an effective voltage from the voltage source in the reaction mode to select ions using mass filtering.