1.6: Mass Spectrometry

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Mass spectrometry operates on the principle that:
1. Compound specific ion fragments can be measured and quanitified
2. Charged particles moving through a magnetic field can be separated from other charges particles according to their mass-to-charge ratios
3. Molecules being analyzed by mass spectrometry must be in the gaseous state
4. Bombardment of molecules by high energy electrons causes ions to be formed
5. All of the above
The molecular ion provides useful information about:
1. The amount of energy required for ionization
2. The molecular weight and information about the possible structure of the molecule
3. The relative intensities of the fragments formed during full scan analysis
4. The analytical purity as well as the intensity of the parent ion
5. All of the above
The main advantage of Electron Ionization is that:
1. The resulting fragmentation is extensive and provides significant structural information about the molecule
2. It is a much faster ionization process than other ionization techniques such as chemical ionization
3. It is a soft ionization process that maximizes the ions life time
4. All of the above
5. None of the above
Chemical Ionization is a process that:
1. Generates full scan spectra characteristic of the molecule being analyzed
2. Is only used to identify large molecules such as proteins and peptides
3. Generates relatively stable ions of high intensity due to its gentle ionization
4. All of the above
5. None of the above
The main advantage of LC/MS over GC/MS is:
1. It has a significant cost advantage
2. It is simpler and faster to use
3. It may be more suitable for compounds that are less volatile or thermally labile
4. All of the above
5. None of the above
The main disadvantage of LC/MS over GC/MS is:
1. The difficulty of converting molecules of interest that are solvated in liquid to the gaseous form
2. Interfacing helium gas to serve as the mobile phase carrier gas
3. Bombarding of the liquid phase by high energy electrons to generate positive ions
4. All of the above
5. None of the above

Answer

e (p. 173)
b (p. 177)
a (p. 176,179)
c (p. 176)
c (p. 182-183)
a (p. 182-183)