Topic 7- Modern Analytical Techniques Flashcards
Infrared radiation is absorbed by any…
Polar bond
What does absorbed infrared radiation do to bonds?
Makes bonds vibrate
Why may C-N bonds not absorb the same frequency as each other?
Because although the same bond, they’re in different environments
Name the 4 stages in Mass Spec?
Ionisation
Acceleration
Deflection
Detection
How are ions “ionised”
Bombarded with electrons to form positive ions.
How are ions accelerated?
High electric potential (field)
How does deflection happen?
Powerful magnetic field
What does the detection part mean?
Ions of lowest mass detected first.
Describe the result of bombarding molecules with high energy electrons?
Leaves fragments with a • or a + (or one fragment with•+)
Mass spectrometry only detects the…. (……s are LOST)
Mass spectrometry ONLY detects the + charged ions (radicals are LOST)
Which part of the mass spectrometer separates ions of different mass?
The magnetic field.
What area is known as the fingerprint region?
Wavenumber below 1500cm-1
Which physical methods of chemical analysis are used in modern breathalysers?
Infrared Spectroscopy
In mass spectra what does the peak intensity correlate to?
How stable the ion is (very intense peak=very stable)
Describe IR spectroscopy
bonds in a molecule absorb infra-red radiation at
characteristic frequencies causing the covalent bonds to vibrate
