Time of Flight Mass Spectrometry Flashcards
What does mass spectrometry do
Mass Spectrometry is a powerful analytical technique
It is the most useful instrument for accurate determination of the relative atomic mass of an element, based on the abundance and mass of each of its isotopes
It is also used to find the relative molecular mass of molecules
As a sample passes through the mass spectrometer, a spectrum is produced of
mass / charge ratio against abundance
The spectrum can be used to find the
relative isotopic abundance, atomic and molecular mass and the structure of a compound
The peak with the highest mass is the
molecular ion peak, M+,
and the peak which has the largest abundance (tallest peak) is called the
base peak
There are several types of mass spectrometer, but all of them are based on an
ionised sample being accelerated through the mass spectrum, and being separated based on the ratio of their charge to their mass
What is Time of Flight Mass Spectrometry
This is a common form of mass spectrometry, where all particles of the sample to be analysed are ionised to form 1+ ions
These 1+ ions are then
accelerated to high speeds, deflected through the spectrometer and then arrive at the detector
As they hit the detector, the mass spectrum graph is produced
The whole of the apparatus is kept under a
high vacuum to prevent any ions that are produced from colliding with molecules in the air
This is a common form of mass spectrometry, where all particles of the sample to be analysed are ionised to form ….ions
These ions are then ……… to high speeds, deflected through the spectrometer and then arrive at the detector
As they hit the ………, the mass spectrum graph is produced
The whole of the apparatus is kept under a high …….. to prevent any ions that are produced from colliding with molecules in the air
1+
accelerated
vacuum
