Two-phase approach to fourier transform ion mobility time-of-flight mass spectrometry

1. A method for ion populations analysis, comprising:

obtaining a first data set that further comprises:

modulating a single ion gate with a first binary On-OFF frequency sweep across a range of frequencies, and

acquiring a first raw data in the time domain at a detector from ion current resulting from the first binary On-OFF frequency sweep,

obtaining a second data set that further comprises:

modulating the single ion gate with a second binary On-OFF frequency sweep across a range of frequencies, wherein the second binary On-OFF frequency sweep is 180° out of phase from the first binary On-OFF frequency sweep, and

acquiring a second raw data in the time domain from received ion current resulting from the second binary On-OFF frequency sweep; and

combining the first and the second data set to provide for raw mobility signals of the ion populations in the time domain for each mass-to-charge (m/z) over a range of selected m/z values,

wherein the range of selected m/z values to obtain each m/z of the ion populations is provided by a hybrid ion mobility mass spectrometer.

2. The method of claim 1 , wherein the combining step further includes utilizing a mathematical transform of the raw mobility signals.

3. The method of claim 2 , wherein the mathematical transform is at least one transform selected from a Fourier transform, a Fast Fourier transform (FFT), and a Hadamard transform.

4. The method of claim 2 , after transform of the raw mobility signals into one or more measured frequencies, the method further comprises: dividing the one or more measured frequencies by the sweep rate in Hertz/seconds (Hz/s) so as to provide a spectrum with peak locations directly corresponding to the drift times within a configured ion mobility spectrometer.

5. The method of claim 1 , where the first and the second binary On-OFF frequency sweeps are provided from a lower frequency limit to an upper frequency limit over a sweep time as determined by a resolving power and/or a sensitivity criteria.

6. The method of claim 5 , wherein the first and the second binary On-OFF frequency sweeps increases linearly to the upper frequency limit.

7. The method of claim 5 , wherein the first and the second binary On-OFF frequency sweeps changes nonlinearly between the lower frequency limit and the upper frequency limit.

8. The method of claim 5 , wherein at least one of amplitude and phase of the first and the second binary On-OFF frequency sweeps changes between the lower frequency limit and the upper frequency limit.

9. The method of claim 5 , wherein the first and the second binary On-OFF frequency sweeps are in a range of between 5 Hz up to 10 kHz.

10. The method of claim 1 , wherein the first and the second binary On-OFF frequency sweeps are configured as a multiplexed two-phase approach to provide for a 50% duty cycle of the generated ion populations.

11. The method of claim 1 , wherein modulating the single ion gate in obtaining the second data set simulates a second ion gate configured within an ion drift region of an ion mobility spectrometer.

12. The method of claim 1 , wherein the mass spectrometer is at least one mass analyzer selected from the group consisting of a quadrupole mass analyzer, a two-dimensional ion trap, a three dimensional ion trap, and a time-of-flight (TOF) analyzer.