Mass Spectroscopy

Question 1

what does a mass spectrometer do

Answer 1

separates individual isotopes in an element

determines the mass of each isotope relative to carbon 12

calculates relative isotopic abundance of each isotope

Question 2

how does a mass spectrometer work (step 1)

Answer 2

the sample is vaporised and then ionised using high energy electrons

Question 3

how does a mass spectrometer work (step 2)

Answer 3

the ions are separated and accelerated according to their mass to change ratio (m/z)
- particles with larger mass experience less deflection due to inertia
- particles with a larger charge experience a larger deflection

Question 4

how does a mass spectrometer work (step 3)

Answer 4

the ions that have a particular mass to charge ratio are detected by a device that counts the number of ions that it it

Question 5

what is the information given out by a mass spectrometer

Answer 5

mass spectrum

Question 6

what is the mass spectrum/mass spectra

Answer 6

it is a graph of relative substance vs mass to charge ratio (m/z)

most ions have one charge to m/z is just m

Question 7

how do we use mass spectra to get % adundance

Answer 7

measure height of each peak

add the heights together to get total height of peaks

then peak height/total peak height x 100 = abundance %

Question 8

what is a mass spectrometry

Answer 8

technique used to measure mass of atoms or molecules

helps us to determine relative abundance and presence of isotopes