Continuous operation high speed ion trap mass spectrometer
The present disclosure discusses a system and method for continuous operation of an ion trap mass spectrometer. The described system does not introduce ions into the ion trap in distinct trapping phase, rather the described system continuously injects ions into the ion trap while continuously scanning out the ions. The system and method described herein achieves a much higher duty cycle and cycle rate when compared to standard mass spectrometer devices.
1. A mass spectrometer comprising:
an ion trap configured to continuously receive ions;
an ion source configured to continuously inject the ions to the ion trap;
an ion detector configured to detection ions when the ions are ejected from the ion trap; and
a controller configured to cause a repeated frequency-scanned voltage signal to be applied to the ion trap during the continuous injection of the ions into the ion trap, the controller configured to alternate between holding the repeated frequency-scanned voltage signal at a first frequency for a first predetermined amount of time and scanning from the first frequency to a second frequency over a second predetermined amount of time, the scanning of the repeated frequency-scanned voltage signal from the first frequency to the second frequency, causing the ejection of the ions from the ion trap.
2. The mass spectrometer of claim 1 , wherein the controller causes the repeated frequency-scanned voltage signal to be applied to a ring electrode of the ion trap.
3. The mass spectrometer of claim 2 , wherein a magnitude of the voltage of the repeated frequency-scanned voltage signal is between about 200 V and about 1000 V.
4. The mass spectrometer of claim 2 , wherein the first frequency is between about 1.3 MHz and about 700 kHz and the second frequency is between about 350 kHz and about 200 kHz.
5. The mass spectrometer of claim 2 , wherein an end-cap electrode of the ion trap is grounded.
6. The mass spectrometer of claim 1 , wherein the controller causes the repeated frequency-scanned voltage signal to be applied to an end-cap electrode of the ion trap.
7. The mass spectrometer of claim 6 , wherein the controller causes a constant fundamental frequency signal to be applied to a ring electrode of the ion trap.
8. The mass spectrometer of claim 7 , wherein the repeated frequency-scanned voltage signal has an initial frequency between about ½ and about ⅛ of the constant fundamental frequency.
9. The mass spectrometer of claim 7 , wherein the fundamental frequency is between about 1.3 MHz and about 200 kHz.
10. The mass spectrometer of claim 7 , wherein a magnitude of the voltage of the repeated frequency-scanned voltage signal is an order of magnitude less than a magnitude of the voltage of the constant fundamental frequency signal.
11. A method of generating a mass spectra, the method comprising;
providing a mass spectrometer comprising,
an ion source configured to continuously inject ions into an ion trap, the ion trap configured to continuously receive ions from the ion source,
an ion detector, and
a controller configured to apply a repeated frequency-scanned voltage signal to the ion trap;
injecting, in a continuous fashion, ions into the ion trap from the ion source;
applying the repeated frequency-scanned voltage signal to the ion trap during the continuous injection of ions into the ion trap, the repeated frequency-scanned voltage signal alternating between holding a first frequency for a first predetermined amount of time and scanning from the first frequency to a second frequency over a second predetermined amount of time, thereby causing the ejection of the ions from the ion trap; and
detecting, by the ion detector, ions ejected from the ion trap.
12. The method of claim 11 , further comprising applying the repeated frequency-scanned voltage signal to a ring electrode of the ion trap.
13. The method of claim 11 , further comprising scanning the repeated frequency-scanned voltage signal from the first frequency to the second frequency according to a logarithmic progression.
14. The method of claim 11 , wherein the first frequency is between about 1.3 MHz and about 700 kHz and the second frequency is between about 350 kHz and about 200 kHz.
15. The method of claim 11 , wherein a magnitude of the voltage of the repeated frequency-scanned voltage signal is between about 200 V and about 1000 V.
16. The method of claim 11 , further comprising applying the repeated frequency-scanned voltage signal to an end-cap electrode of the ion trap.
17. The method of claim 16 , further comprising applying a fundamental frequency voltage signal to a ring electrode of the ion trap.
18. The method of claim 17 , further comprising applying the fundamental frequency voltage signal to the ring electrode of the ion trap at a constant frequency.
19. The method of claim 17 , wherein the repeated frequency-scanned voltage signal has an initial frequency between about ½ and about ⅛ of the fundamental frequency.
20. The method of claim 17 , wherein a magnitude of the voltage of the repeated frequency-scanned voltage signal is an order of magnitude less than a magnitude of the voltage of the fundamental frequency signal.