Portable mass spectrometers
View Patent ↗The present invention relates to a mass spectrometer, and more specifically a portable mass spectrometer. In one implementation, the mass spectrometer includes a toroidal transformer. In another implementation, the mass spectrometer includes feedback circuitry to monitor signals applied in the mass spectrometer.
1. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal, the amplifying circuit including a toroidally shaped transformer; and
an ion trap including an electrode; wherein the amplified radio frequency voltage signal is applied to the electrode to analyze the sample.
2. The mass spectrometer of claim 1 , wherein said ion trap comprises a cylindrical ion trap.
3. The mass spectrometer of claim 1 , wherein said toroidally-shaped transformer has an outer diameter less than or equal to approximately four inches.
4. The mass spectrometer of claim 1 , wherein said toroidally-shaped transformer has a cross-sectional width less than or equal to approximately one inch.
5. The mass spectrometer of claim 1 , wherein said transformer has a primary coil and a secondary coil, said primary coil having a range of approximately 2 to 5 windings, and said secondary coil having a range of approximately 200 to 500 windings.
6. The mass spectrometer of claim 5 , wherein said transformer has a turn ratio in the range of approximately 50:1 to 150:1.
7. The mass spectrometer of claim 5 , wherein said transformer has a core formed of a magnetic material, said primary coil and said secondary coil being wound around said core.
8. The mass spectrometer of claim 1 , wherein said magnetic material comprises at least one of ferrite and iron.
9. The mass spectrometer of claim 1 , wherein the amplified radio frequency voltage signal has a peak amplitude in the range of approximately 500 volts to 6000 volts.
10. The mass spectrometer of claim 1 , wherein said electrode comprises a ring electrode.
11. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal;
the amplifying circuit including a toroidally shaped transformer;
a mass analyzer, wherein the amplified radio frequency voltage signal is applied to the mass analyzer to analyze the sample;
a feedback circuit for generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the mass analyzer; and
a signal processor to instruct the signal generator to alter the radio frequency voltage signal based on the feedback radio frequency voltage signal.
12. The mass spectrometer of claim 11 , wherein the feedback circuit includes an impedance divider.
13. The mass spectrometer of claim 12 , further comprising a database of reference radio frequency voltage signals, wherein the signal processor compares the feedback radio frequency voltage signal to a reference radio frequency voltage signal in the database to determine whether to instruct the signal generator to alter the radio frequency voltage signal.
14. The mass spectrometer of claim 11 , wherein the feedback circuit includes a capacitor to sense the voltage applied to the mass analyzer capacitively.
15. The mass spectrometer of claim 14 , wherein the capacitor has a capacitance in the range of 0.5 ρf to 5 ρf.
16. The mass spectrometer of claim 11 , wherein the feedback circuit is located on a circuit board and wherein the feedback circuit senses the voltage applied to the mass analyzer based on the capacitance of the circuit board.
17. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal, wherein the signal generator includes a tuning capacitor to tune the radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal, the amplifying circuit including a toroidally shaped transformer; and
an ion trap including an electrode; wherein the amplified radio frequency voltage signal is applied to the electrode to analyze the sample.
18. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal an amplifying circuit to amplify the radio frequency voltage signal, the amplifying circuit including a toroidally shaped transformer;
an ion trap including an electrode; wherein the amplified radio frequency voltage signal is applied to the electrode to analyze the sample; and
a feedthrough comprising a wire embedded in epoxy to apply the amplified radio frequency voltage signal to the electrode.
19. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal, the amplifying circuit including a toroidally shaped transformer;
a cylindrical ion trap including an electrode; wherein the amplified radio frequency voltage signal is applied to the electrode to analyze the sample;
a feedback circuit for generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the electrode; and
a signal processor to instruct the signal generator to alter the radio frequency voltage signal based on the feedback radio frequency voltage signal.
20. The mass spectrometer of claim 19 , wherein said toroidally-shaped transformer has an outer diameter less than or equal to approximately four inches.
21. The mass spectrometer of claim 19 , wherein said toroidally-shaped transformer has a cross-sectional width less than or equal to approximately one inch.
22. The mass spectrometer of claim 19 , wherein said transformer has a primary coil and a secondary coil, said primary coil having a range of approximately 2 to 5 windings, and said secondary coil having a range of approximately 200 to 500 windings.
23. The mass spectrometer of claim 22 , wherein said transformer has a turn ratio in the range of approximately 50:1 to 150:1.
24. The mass spectrometer of claim 22 , wherein said transformer has a core formed of a magnetic material, said primary coil and said secondary coil being wound around said core.
25. The mass spectrometer of claim 19 , wherein said magnetic material comprises at least one of ferrite and iron.
26. The mass spectrometer of claim 19 , wherein the amplified radio frequency voltage signal has a peak amplitude approximately between 500 volts and 6000 volts.
27. The mass spectrometer of claim 19 , wherein said electrode comprises a ring electrode.
28. The mass spectrometer of claim 19 , wherein the feedback circuit includes an impedance divider.
29. The mass spectrometer of claim 19 , further comprising a database of reference radio frequency voltage signals, wherein the signal processor compares the feedback radio frequency voltage signal to a reference radio frequency voltage signal in the database to determine whether to instruct the signal generator to alter the radio frequency voltage signal.
30. The mass spectrometer of claim 19 , wherein the feedback circuit includes a capacitor to sense the voltage applied to the mass analyzer capacitively.
31. The mass spectrometer of claim 30 , wherein the capacitor has a capacitance in the range of about 0.5 ρf to 5 ρf.
32. The mass spectrometer of claim 19 , wherein the signal generator includes a tuning capacitor to tune the radio frequency voltage signal.
33. The mass spectrometer of claim 19 , further comprising a feedthrough comprising a wire embedded in epoxy to apply the amplified radio frequency voltage signal to the electrode.
34. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal, the amplifying circuit including a toroidally shaped transformer;
an ion trap including an electrode; wherein the amplified radio frequency voltage signal is applied to the electrode to analyze the sample; and
a housing encasing the signal generator, amplifying circuit, and ion trap having dimensions of no greater than about 6 inches×7 inches×8 inches.
35. A method of analyzing a sample with a mass spectrometer, comprising:
generating a radio frequency voltage signal;
amplifying the radio frequency voltage signal using a toroidally shaped transformer; and
applying the amplified radio frequency voltage to an electrode of an ion trap to analyze the sample.
36. A method of analyzing a sample with a mass spectrometer, comprising:
generating a radio frequency voltage signal;
amplifying the radio frequency voltage signal;
including a toroidally shaped transformer;
applying the amplified radio frequency voltage signal to a mass analyzer to analyze the sample;
generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the mass analyzer; and
altering the radio frequency voltage signal based on the feedback radio frequency voltage signal.
37. A method of analyzing a sample with a mass spectrometer, comprising:
generating a radio frequency voltage signal;
amplifying the radio frequency voltage signal using a toroidally shaped transformer;
applying the amplified radio frequency voltage signal to an electrode of a cylindrical ion trap to analyze the sample;
generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the electrode; and
altering the radio frequency voltage signal based on the feedback radio frequency voltage signal.
38. A mass spectrometer for analyzing a sample, comprising:
a signal generator to generate a radio frequency voltage signal;
an amplifying circuit to amplify the radio frequency voltage signal;
the amplifying circuit including a toroidally shaped transformer;
a mass analyzer, wherein the amplified radio frequency voltage signal is applied to the mass analyzer to analyze the sample;
a feedback circuit for generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the mass analyzer; and
wherein the mass analyzer determines the mass of molecules contained in the sample based on a measurement of the feedback radio frequency voltage signal.
39. The mass spectrometer of claim 38 , wherein the feedback circuit includes an impedance divider.
40. The mass spectrometer of claim 38 , wherein the measurement of the feedback radio frequency voltage signal is made using a capacitor to sense the voltage.
41. The mass spectrometer of claim 40 , wherein the capacitor has a capacitance in the range of 0.5 ρf to 5 ρf.
42. The mass spectrometer of claim 38 , wherein the feedback circuit is located on a circuit board and wherein the measurement of the feedback radio frequency voltage signal is made capacitively using the capacitance of the circuit board.
43. A method of analyzing a sample with a mass spectrometer, comprising:
generating a radio frequency voltage signal;
amplifying the radio frequency voltage signal;
including a toroidally shaped transformer;
applying the amplified radio frequency voltage signal to a mass analyzer to analyze the sample;
generating a feedback radio frequency voltage signal based on the amplified radio frequency voltage signal applied to the mass analyzer;
measuring the feedback radio frequency voltage signal; and
determining the mass of molecules contained in the sample based on the measurement of the feedback radio frequency voltage signal.