Mass Spectroscopy Flashcards
What are the three main things that can be determined by mass spectroscopy?
The molecular mass
The molecular formula
Certain structural features of the compound
What are the three steps in mass spectroscopy?
Ionisation of the sample
Separation of the resulting ions
Detection of the ions
What is the process of mass spectroscopy in an abbreviation form?
ABC-Electron Gun->ABC+-Ion Shakes Apart->AB+, C+; or A+, BC+
What is the process of mass spectroscopy in worded form?
Molecule-Electron Gun->Molecular Ion-Ion Shakes Apart->Fragmentation ions or neural particles
What does mass spectrometry report?
The mass to charge ratio (m/z)
Does mass spectrometry report molecular weight?
No
What does z usually equal in m/z?
1
What two things do we look for in mass spectrometry?
The highest m/z
Fragents
Why do we look for the highest m/z in mass spectrometry?
It represents the molecular ion (M)
Why do we look for fragments m/z in mass spectrometry?
We can often identify functional groups by fragmentation patterns
What are the two rules for preference in bond breaking?
Weak bonds break in preference to strong bonds
Bonds that break to form more stable fragments break in preference to those that form less stable fragments
What is the mass of a H2O fragment in mass spectrometry?
18
What is the mass of an NH3 fragment in mass spectrometry?
17
What is the mass of a Cl fragment in mass spectrometry?
35
What is the mass of a C=O fragment in mass spectrometry?
28
