A MASS SPECTROMETER AND A METHOD FOR ANALYZING A SAMPLE THEREIN

1 . A method for analyzing a sample in a mass spectrometer, the method comprising:

storing ions produced from the sample in an ion trap of the mass spectrometer; and

applying a scan function to the ion trap comprising

exciting at least a portion of the ions in the ion trap selectively over time to fragment precursor ions into product ions, and

ejecting at least one of the product ions and the precursor ions from the ion trap,

wherein the scan function comprises a constant radio frequency voltage, a sweeping excitation frequency, and successive ejection frequency scans of variable duration and variable frequency range based on the sweeping excitation frequency.

2 . The method of claim 1 , wherein the sweeping excitation frequency sweeps from a first frequency to a second frequency, wherein the second frequency is less than the first frequency.

3 . The method of claim 1 , wherein:

the sweeping excitation frequency excites a first precursor ion at a first excitation frequency to form a first set of product ions from dissociation of the first precursor ion; and

a first scan of the successive ejection frequency scans sequentially ejects the first set of product ions from the ion trap.

4 . The method of claim 3 , wherein:

the sweeping excitation frequency excites a second precursor ion at a second excitation frequency to form a second set of product ions from dissociation of the second precursor ion; and

a second scan of the successive ejection frequency scans sequentially ejects the second set of product ions from the ion trap, wherein the first precursor ion comprises a first mass to charge ratio less than a second mass to charge ratio of the second precursor ion and the first scan is performed for a first duration less than a second duration of the second scan.

5 . The method of claim 3 , wherein the first scan of the successive ejection frequency scans spans a frequency range of a frequency corresponding to half of the radio frequency voltage to the first excitation frequency.

6 . The method of claim 1 , wherein each scan of the successive ejection frequency scans comprises a frequency range greater than a frequency range of an immediately preceding scan of the successive ejection frequency scans.

7 . The method of claim 1 , wherein providing ions produced from the sample into the ion trap of the mass spectrometer comprises at least one of:

ionizing the sample with an ionizer and transferring the ions to the ion trap; and

providing the sample into the ion trap and ionizing the sample in the ion trap.

8 . The method of claim 1 , further comprising detecting at least a portion of at least one of the product ions and the precursor ions.

9 . A mass spectrometer configured to perform the method of claim 1 .

10 . A method for analyzing a sample in a mass spectrometer, the method comprising:

storing ions produced from the sample in an ion trap of the mass spectrometer; and

applying a scan function to the ion trap comprising

exciting at least a portion of the ions selectively over time, and

ejecting at least one of product ions and precursor ions from the ion trap, wherein the scan function comprises a sweeping radio frequency voltage, an excitation frequency, and successive ejection frequency scans, wherein the sweeping radio frequency voltage is ramped from a first voltage to a second voltage greater than the first voltage.

11 . The method of claim 10 , wherein each of the successive ejection frequency scans comprises an identical predetermined duration and identical predetermined frequency range.

12 . The method of claim 10 , wherein each of the successive ejection frequency scans comprises an identical frequency range.

13 . The method of claim 10 , wherein a frequency range of the successive ejection frequency scans spans a frequency range of a frequency corresponding to half of the radio frequency voltage to the excitation frequency.

14 . The method of claim 10 , wherein a ramp from the first voltage to the second voltage is linear.

15 . The method of claim 10 , wherein providing ions of the sample into the ion trap of the mass spectrometer comprises at least one of:

ionizing the sample with an ionization device and transferring the ions to the ion trap; and

providing the sample into the ion trap and ionizing the sample in the ion trap.

16 . The method of claim 10 , further comprising detecting at least a portion of at least one of the product ions and the precursor ions.

17 . A mass spectrometer comprising:

an ion trap configured to receive ions produced from a sample; and

a controller configured to apply a scan function to the ion trap comprising

excite at least a portion of the ions selectively over time, and

eject at least one of product ions and precursor ions from the ion trap,

wherein the scan function comprises a sweeping radio frequency voltage, an excitation frequency, and successive ejection frequency scans, and the sweeping radio frequency voltage is ramped from a first voltage to a second voltage greater than the first voltage.

18 . The mass spectrometer of claim 17 , wherein the ion trap is a quadrupole ion trap and the quadrupole ion trap comprises one of a three-dimensional quadrupole ion trap, a linear quadrupole ion trap, a toroidal ion trap, a cylindrical ion trap, and a rectilinear ion trap.

19 . (canceled)

20 . The mass spectrometer of claim 17 , wherein the controller configured to apply the scan function comprises the controller to apply the excitation frequency and the successive ejection frequency scans to a first set of electrodes.

21 . The mass spectrometer of claim 17 , wherein the controller configured to apply the scan function comprises the controller to apply the excitation frequency to a first set of electrodes and apply the successive ejection frequency scans to a second set of electrodes, wherein no electrode in the first set is in the second set.

22 - 61 . (canceled)