5.9 Questions

1. Why are most mass filters maintained at a low pressure?

2. List the common ways samples are introduced into a MS system.

3. How can solid samples be introduced into a MS?

4. Draw and explain how the interface between a GC and a MS works.

5. Why do capillary columns, versus packed columns, work best for MS interfaces?

6. Explain the difference between hard and soft ionization in GC-MS.

7. Why does soft ionization reduce the fragmentation of analytes in GC-MS?

8. Write the chemical reactions occurring when methane is used in soft ionization.

9. Draw and explain how the interface between a LC and a MS works.

10. What is the major problem with interfacing LC (ESI) to MS?

11. Explain how MALDI works. What types of samples is it commonly used for. What type of MS is it commonly coupled with?

12. Draw and explain how the interface between a CE (ESI) and a MS works.

13. Explain resolution with respect to mass filters. Give relevant resolution numbers.

14. Draw and explain how a magnetic sector mass filter works.

15. Draw and explain (in detail) how a quadrupole mass filter works.

16. The governing equation of the quadrupole mass filter consists of a six-parameter differential equation. Which two parameters are used to control the mass filter?

17. What is the purpose of the dc voltage in the quadrupole MS?

18. What is the purpose of the ac cycle in the quadrupole MS?

19. How does the low mass and high mass filters work to create a stable cation region in the quadrupole MS?

20. Explain the mass scan line in the quadrupole MS figures.

21. What is the purpose of sweeping the dc-ac voltages?

22. Extend the concepts of a linear quadrupole mass filter, explained above, to explain how the quadrupole ion trap mass filter works.

23. How is the mass range of a quadrupole ion trap mass filter extended?

24. Explain the concept of resonance ejection in ion trap mass filters.

25. Draw and explain how a time-of-flight mass filter works.

26. Contrast traditional TOF and ion mobility MS.

27. Draw and explain how a PTR-MS works.

28. Give a brief explanation of how an Ion Cyclotron works.

29. Draw and explain how a double focusing mass filter works. What are its advantages?

30. What is tandem mass spectrometry?

31. What types of detectors are used in mass spectrometry?

32. Use the date in Table 5.2 to contrast the various types of mass filters. Which is the most economical? Which has the best mass resolution?

Frank's Homepage

Section 5.10

©Dunnivant & Ginsbach, 2008