Relative mass and mass Spectrometer Flashcards
How is the sample ionised?
It’s injected through a fine hypodermic needle and a very high voltage is applied to the end of the needle
What happens after the solvent is ionised ?
The solvent evaporates leaving 1+ ions
How are the ions accelerated ?
Electric field accelerates them.
What does the acceleration give the ions ?
Constant kinetic energy
After acceleration what is the name of the next stage?
Ion drift
When the ions leave the electric field what do they have ?
A constant speed and kinetic energy.
What is there none of which makes them drift ?
No electric field
Ions with lower mass/charge rations do what ?
Drift at higher speeds
What is the detector ?
A negatively charged plate.
What is produced when the ions hit the plate ?
A current. The more ions that hit the detector the bigger the current
The mass of the ion hitting the detector can be calculated from what ?
The time it takes to reach the detector
What is the relative atomic mass ?
The average mass of 1 atom compared to 1/12 mass of the carbon-12 isotope.
Average mass of an atom
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1/12 mass of carbon 12
How do u work out average mass/ relative atomic mass ?
Total abundance
How do u find the mr for a molecule on the mass spectra ?
The molecular ion is the peak on the right hand side with the larger m/z value.
What does the mass spectrometer give us ?
Accurate information about relative isotopic masses and relative abundance of isotopes
