7.
A major advance in the application of mass spectrometry to macromolecule came with the development of techniques to overcome which One of the following problems:
A:
Macromolecules were insoluble in solvents used in mass spectrometry
B:
Mass spectrometric analyses were too complex
C:
Mass spectrometric analysis involved molecules in gas phase
D:
Most macromolecules could not be purified to the degree needed for this technique
The answer is:
C