Matrix methods for the calculation of stability diagrams in quadrupole mass spectrometry
- 619 Downloads
- 60 Citations
Abstract
The theory of the computer calculation of the stability of ion motion in periodic quadrupole fields is considered. A matrix approach for the numerical solution of the Hill equation and examples of calculations of stability diagrams are described. The advantage of this method is that it can be used for any periodic waveform. The stability diagrams with periodic rectangular waveform voltages are calculated with this approach. Calculations of the conventional stability diagram of the 3-D ion trap and the first six regions of stability of a mass filter with this method are presented. The stability of the ion motion for the case of a trapping voltage with two or more frequencies is also discussed. It is shown that quadrupole excitation with the rational angular frequency ω = NΩ/P (where N, P are integers and Ω is the angular frequency of the trapping field) leads to splitting of the stability diagram along iso-β lines. Each stable region of the unperturbed diagram splits into P stable bands. The widths of the unstable resonance lines depend on the amplitude of the auxiliary voltage and the frequency. With a low auxiliary frequency splitting of the stability diagram is greater near the boundaries of the unperturbed diagram. It is also shown that amplitude modulation of the trapping RF voltage by an auxiliary signal is equivalent to quadrupole excitation with three frequencies. The effect of modulation by a rational frequency is similar to the case of quadrupole excitation, although splitting of the stability diagram differs to some extent. The methods and results of these calculations will be useful for studies of higher stability regions, resonant excitation, and non-sinusoidal trapping voltages.
Keywords
Parametric Resonance Excitation Parameter Stability Diagram Mass Filter Paul TrapReferences
- 1.Ince, E. Researches into the Characteristic Numbers of the Mathieu Equation. Proceedings of the Royal Society of Edinburgh; Neiland Co. Ltd.: Edinburgh, 1925–1926; XLVI, 20–29.Google Scholar
- 2.McLachlan, N. W. Theory and Applications of Mathieu Functions; Clarendon: Oxford, 1947.Google Scholar
- 3.Quadrupole Mass Spectrometry and its Applications; Dawson, P. H., Ed.; Elsevier: Amsterdam, 1976; reissued by AIP Press: Woodbury, NY, 1995, pp 65–77.Google Scholar
- 4.March, R. E., Hughes, R. J., Todd, J. F. J. Quadrupole Storage Mass Spectrometry, Wiley Interscience, 1989, pp 31–73.Google Scholar
- 5. (a)Dawson, P. H.; Yu, B. The Second Stability Region of the Quadrupole Mass Filter. II. Experimental Results. Int. J. Mass Spectrom. Ion Proc. 1984, 56, 41–50.CrossRefGoogle Scholar
- 5. (b)Konenkov, N. V.; Kratenko, V. I. Characteristics of a Quadrupole Mass Filter in the Separation Mode of a Few Stability Regions. Int. J. Mass Spectrom. Ion Proc. 1991, 108, 115–136.CrossRefGoogle Scholar
- 5. (c)Du, Z.; Douglas, D. J.; Konenkov, N. V. Elemental Analysis with Quadrupole Mass Filters Operated in Higher Stability Regions. J. Anal. Atom. Spectrom. 1999, 14, 1111–1119.CrossRefGoogle Scholar
- 6. (a)Paul, W.; Reinhard, H. P.; Von Zahn, U. Das Elektrische Massenfilter als Massenspectrometer und Isotopentrenner. Z. Phys. 1958, 152, 143–182.CrossRefGoogle Scholar
- 6. (b)Vedel, F.; Vedel, M.; March, R. E. New Schemes for Resonant Ejection in RF Quadrupolar Ion Traps. Int. J. Mass Spectrom. Ion Proc. 1990, 99, 125–138.CrossRefGoogle Scholar
- 6. (c)Alfred, R. L.; Londry, F. A.; March, R. E. Resonance Excitation of Ions Stored in a Quadrupole Ion Trap. Part IV. Theory of Quadrupolar Excitation. Int. J. Mass Spectrom. Ion Proc. 1993, 124, 171–185.CrossRefGoogle Scholar
- 6. (d)Makarov, A. Resonance Ejection from the Paul Trap: A Theoretical Treatment Incorporating a Weak Octopole Field. Anal. Chem. 1996, 68, 4257–4263.CrossRefGoogle Scholar
- 7. (a)Richards, J. A.; Huey, R. M.; Hiller, J. A New Operating Mode for the Quadrupole Mass Filter. Int. J. Mass Spectrom. Ion Proc. 1973, 12, 317–339.CrossRefGoogle Scholar
- 7. (b)Sheretov, E. P.; Terentyev, V. A. The Fundamentals of Theory of Quadrupole Mass Spectrometry with Pulsed Voltage Waveform. Russ. J. Tech. Phys. 1972, 42, 953–962.Google Scholar
- 8.Floquet, G. Sur les Equations Differentielles Lineares a Coefficients Periodiques. Ann. Ecole Norm. Sup. Paris 1883, 12, 47–89.Google Scholar
- 9. (a)Hale, J. K. Ordinary Differential Equations; Wiley Inter-science: New York, 1969, pp 117–131.Google Scholar
- 9. (b)Hartman, P. Ordinary Differential Equations; 2nd ed., Burkhauser, Boston, 1982, pp 60–62.Google Scholar
- 10.Pipes, L. A. Matrix Solution of Equations of the Mathieu-Hill Type. J. Appl. Phys. 1953, 24, 902–910.CrossRefGoogle Scholar
- 11.Waldren, R. M.; Todd, J. F. J. The Use of Matrix Methods and Phase-Space Dynamics for the Modelling of Quadrupole-Type Device Performance. In Dynamic Mass Spectrometry; Price, D.; Todd, J. F. J., Eds.; Heyden: London, 1978; Chap V; 14–40.Google Scholar
- 12. (a)Dawson, P. H. Numerical Calculation. In Quadrupole Mass Spectrometry and its Applications. Elsevier: Amsterdam, 1976; 84.Google Scholar
- 12. (b)Humphries, S., Jr.; Principles of Charged Particle Acceleration; John Wiley and Sons: New York, 1986.Google Scholar
- 12. (c)Arnol’d, V. I. Ordinary Differential Equations, 3rd ed.; Springer-Verlag: Berlin, 1991; pp 256–264.Google Scholar
- 13.Symon, K. R. Mechanics. Addison-Wesley Publishing Co. Inc.: Reading, 1964; p 399.Google Scholar
- 14.Ding, L.; Kumashiro, S. Ion Motion in the Rectangular Wave Quadrupole Field and Digital Operation Mode of a Quadrupole Mass Spectrometer. Chinese Vac. Sci. Tech. 2001, 3, 176–181.Google Scholar
- 15.Sudakov, M. Stability Diagrams of Ions in Radio Frequency Mass Spectrometry. Russ. J. Tech. Phys. 1994, 65, 170–178.Google Scholar
- 16. (a)Kaiser, R. E., Jr.; Cooks, R. G.; Stafford, G. C.; Syka, J. E. P.; Hemberger, P. H. Operation of a Quadrupole Ion Trap Mass Spectrometer to Achieve High Mass/Charge Ratios. Int. J. Mass Spectrom. Ion Proc. 1991, 106, 79–115.CrossRefGoogle Scholar
- 16. (b)Schwartz, J. C.; Syka, J. E. P.; Jardine, I. High Resolution in a Quadrupole Ion Trap Mass Spectrometer. J. Am. Soc. Mass Spectrom. 1991, 2, 198–204.CrossRefGoogle Scholar
- 16. (c)Londry, F. A.; Wells, G. J.; March, R. E. Enhanced Mass Resolution in a Quadrupole Ion Trap. Rapid Commun. Mass Spectrom. 1993, 7, 43–45.CrossRefGoogle Scholar
- 17.Sevugarajan, S.; Menon, A. G. Frequency Perturbation in Nonlinear Paul Traps: A Simulation Study of the Effect of Geometric Aberration, Space Charge, Dipolar Excitation, and Damping on Ion Axial Secular Frequency. Int. J. Mass Spectrom. 2000, 197, 263–278.CrossRefGoogle Scholar
- 18.Alheit, R.; Kleineidam, S.; Vedel, F.; Vedel, M.; Werth, G. Higher Order Non-Linear Resonances in a Paul Trap. Int. J. Mass Spectrom. Ion Proc. 1996, 154, 155–169.CrossRefGoogle Scholar
- 19.Chen, W.; Collings, B. A.; Douglas, D. J. High-Resolution Mass Spectrometry with a Quadrupole Operated in the Fourth Stability Region. Anal. Chem. 2000, 72, 540–545.CrossRefGoogle Scholar
- 20. (a)Landau, L. D.; Lifshitz, E. M. Mechanics, 3rd ed. Pergamon Press: Oxford, 1960, pp 80–83.Google Scholar
- 20. (b)Bogolubov, N. N.; Mitropol’skii, Y. A. Problems of the Asymptotic Theory of Non-stationary Vibrations; Israel Program for Scientific Translations: Jerusalem, 1965.Google Scholar
- 21.Sudakov, M.; Konenkov, N.; Douglas, D. J.; Glebova, T. Excitation Frequencies of Ions Confined in a Quadrupole Field With Quadrupole Excitation. J. Am. Soc. Mass Spectrom. 2000, 11, 11–18.CrossRefGoogle Scholar
- 22.Kozo, M. Quadrupole Mass Spectrometer, US patent 5, 227, 629, July 13, 1993.Google Scholar
- 23. (a)Konenkov, N. V.; Cousins, L. M.; Baranov, V. I.; Sudakov, M. Y. Quadrupole Mass Filter Operation with Auxiliary Quadrupolar Excitation: Theory and Experiment. Int. J. Mass Spectrom 2001, 208, 17–27.CrossRefGoogle Scholar
- 23. (b)Baranov, V. I.; Konenkov, N. V.; Tanner, S. D. QMF Operation with Quadrupole Excitation. In Plasma Source Mass Spectrometry, the New Millenium; Holland, G.; Tanner, S. D., Eds.; Royal Society of Chemistry: Cambridge, 2001, pp 63–72.CrossRefGoogle Scholar
- 24.Du, Z.; Olney, T.; Douglas, D. J. Inductively Coupled Plasma Mass Spectrometry with a Quadrupole Mass Filter Operated in the Third Stability Region. J. Am. Soc. Mass Spectrom. 1997, 8, 1230–1236.CrossRefGoogle Scholar
- 25. (a)Collings, B. A.; Douglas, D. J. Observation of Higher Order Quadrupole Excitation Frequencies in a Linear Ion Trap. J. Am. Soc. Mass Spectrom. 2000, 11, 1016–1022.CrossRefGoogle Scholar
- 25. (b)Collings, B. A.; Sudakov, M.; Londry, F. Resonance Shifts in the Excitation of the n = 0, K = 1 to 6 Quadrupolar Resonances for Ions Confined in a Linear Ion Trap. J. Am. Soc. Mass Spectrom., in press.Google Scholar
- 26.Sudakov, M. Stability Diagram of Secular Motion of Ions Trapped in RF Quadrupole Field with Auxiliary Harmonic Excitation (in Russian). Pisma JTP 2000, 26, 46–51.Google Scholar
- 27.Sheretov, E. P.; Gurov, V. S.; Kolotilin, B. I. Modulation Parametric Resonances and Their Influence on Stability Diagram Structure. Int. J. Mass Spectrom. 1999, 184, 207–216.CrossRefGoogle Scholar
- 28.Arnol’d, V. I. Comments on Perturbation Theory for Mathieu-Like Problems. Russ. Uspehi Math. Sci. 1983, 38, 189–203.Google Scholar
- 29.Cha, B.; Sudakov, M.; Douglas, D. J. unpublished.Google Scholar
- 30. (a)Razvi, M. A.; Chu, X. Z.; Alheit, R.; Werth, G.; Blumel, R. Fractional Frequency Collective Parametric Resonance of an Ion Cloud in a Paul Trap. Phys. Rev. A 1998, 58, R34-R37.CrossRefGoogle Scholar
- 30. (b)Chu, X. Z.; Holzki, M.; Alheit, R.; Werth, G. Observation of High-Order Motional Resonances of an Ion Cloud in a Paul Trap. Int. J. Mass Spectrom. Ion Proc. 1998, 173, 107–112.CrossRefGoogle Scholar
- 31.Rettinghaus, G. Ph.D. Thesis, Bonn University, 1965, unpublished.Google Scholar
- 32.Alheit, R.; Chu, X. Z.; Hofer, M.; Holzki, M.; Werth, G.; Blumel, R. Nonlinear Collective Oscillations of an Ion Cloud in a Paul Trap. Phys. Rev. A 1997, 56, 4023–4031.CrossRefGoogle Scholar