Mass Spec

Question 1

what are the 4 stages off mass spec

Answer 1

Ionisation
Acceleration
Drift
Detection

Question 2

Name the two types of ionisation

Answer 2

Electrospray and electron impact

Question 3

Explain how electrospray ionisation works

Answer 3

Sample is dissolved in a volatile solvent
Injected through a hypodermic needle
Connected to a high voltage supply
Species gains a proton

Question 4

Explain how electron impact ionisation works

Answer 4

High energy electrons are fired at the species from an electron gun
Which knocks an electron out of orbit in the species
Forming a 1+ ion

Question 5

Explain the acceleration step in mass spec

Answer 5

Positively charged ions are accelerated towards a negatively charged plate. All ions travel at the same speed because they have the same charge

Question 6

Explain the drift stage of mass spec

Answer 6

Ions are left to travel in the drift tube. Lighter ions travel faster

Question 7

Explain the detection stage of mass spec

Answer 7

Species gain an electron at the negatively charged detection plate which induces a charge