Systems and methods using a gas mixture to select ions
Certain configurations described herein are directed to mass spectrometer systems that can use a gas mixture to select and/or detect ions. In some instances, the gas mixture can be used in both a collision mode and in a reaction mode to provide improved detection limits using the same gas mixture.
1. A system configured to permit switching of a cell between at least two modes comprising a collision mode and a reaction mode to select ions received by the cell, the system comprising:
a cell configured to receive a gas mixture comprising a binary gas mixture in the collision mode to pressurize the cell and configured to receive the same gas mixture comprising the binary gas mixture in the reaction mode to pressurize the cell; and
a processor electrically coupled to the cell, the processor configured to provide a voltage to the pressurized cell comprising the gas mixture in the collision mode to facilitate the transmission of select ions with an energy greater than an energy barrier induced by the provided first voltage, wherein the processor is further configured to provide a second voltage to the pressurized cell comprising the gas mixture in the reaction mode to guide select ions into a mass filter fluidically coupled to the cell.
2. The system of claim 1 , in which the processor is further configured to permit switching of the cell to a vented mode.
3. The system of claim 1 , in which the system further comprises a single gas inlet fluidically coupled to the cell to provide the gas mixture comprising the binary gas mixture.
4. The system of claim 3 , in which the cell comprises a multipole rod set comprising of 2, 4, 6, 8, or 10 rods.
5. The system of claim 4 , in which the cell further comprises an exit member positioned proximate to an exit aperture of the cell and electrically coupled to a voltage source, the exit member configured to direct analyte ions in the pressurized cell toward the exit aperture of the cell.
6. The system of claim 5 , in which the exit member can be set at a voltage between −60 Volts and +20 Volts in the collision mode of the pressurized cell.
7. The system of claim 5 , in which the exit member can be set at a voltage between −60 Volts and +20 Volts in the reaction mode of the pressurized cell.
8. The system of claim 5 , in which the cell further comprises an entrance member positioned proximate to an entrance aperture of the cell and electrically coupled to a voltage source, the entrance member configured to direct analyte ions into the pressurized cell toward the entrance aperture of the cell.
9. The system of claim 8 , in which the entrance member can be set at a voltage between −60 Volts and +20 Volts in the collision mode of the pressurized cell.
10. The system of claim 8 , in which the entrance member can be set at a voltage substantially similar to a voltage provided to the exit member when the pressurized cell is in the reaction mode.
11. The system of claim 1 , in which the cell is configured to switch from the collision mode to the reaction mode while maintaining the same gas flow or changing to a different flow level by switching the voltages on the entrance member and exit member and optionally changing the energy barrier between the cell and the mass analyzer.
12. The system of claim 1 , in which the cell is configured to switch from the reaction mode to the collision mode while maintaining the same gas flow or changing to a different flow level by switching the voltages on the entrance member and the exit member and optionally changing the energy barrier between the cell and the mass analyzer.
13. The system of claim 1 , further comprising axial electrodes electrically coupled to a voltage source and configured to provide an axial field to direct ions toward an exit aperture of the pressurized cell.
14. The system of claim 13 , in which the axial field comprises a field gradient between −500 V/cm and 500 V/cm.
15. The system of claim 1 , in which the processor is further configured to provide an offset voltage to the pressurized cell.
16. The system of claim 15 , further comprising a mass analyzer fluidically coupled to the cell comprising the offset voltage.
17. The system of claim 16 , in which an offset voltage of the fluidically coupled mass analyzer is more positive than the offset voltage of the cell when the cell is in the collision mode.
18. The system of claim 16 , in which an offset voltage of the fluidically coupled mass analyzer is more negative than the offset voltage of the cell when the cell is in the reaction mode.
19. The system of claim 16 , further comprising an ionization source fluidically coupled to the cell.
20. The system of claim 1 , in which the cell is configured to use a binary mixture of helium gas and hydrogen gas in the collision mode and in the reaction mode.