Modern Analytical Techniques Flashcards
What sized samples are used for mass spectrometry?
Small samples.
What are the four stages of mass spectrometry?
Ionisation.
Acceleration.
Deflection.
Detection.
What happens in the ionisation stage of mass spectrometry?
The sample is subject to a beam of high energy electrons.
Only particles with what charge can be deflected and detected in a mass spectrometer?
A positive charge.
The final M+ peak shows what?
The molecular ion which indicates the molecular mass.
What causes the peaks other than the molecular ion peaks on a mass spectrum?
Ionised fragments.
What do tall fragment peaks mean on a mass spectrum?
Taller peaks mean the fragments are more stable.
What is a typical organic fragment that makes a peak at 49 on a mass spectrum?
C2H5+
What is the infrared spectroscopy peak for a OH bond?
A broad peak at around 3000cm^-1.
Sharp if C=O is also present in molecule.
Round if only OH bond.
