T.o.f - Mass Spectrometer Flashcards
What is ionisation stage 1 of low Mr elements?
The electron gun fires high energy electrons therefore electrons are knocked off each particle by the high energy electrons to form 1+ ions.
What does low Mr elements become when an electron is kicked off?
Gaseous state
What happens during stage 1 ionisation of high Mr compounds?
The compound gains a proton and becomes a positive ion when they leave the needle.
How do positive ions accelerate?
By a negative electric plate.
What causes a fine mist?
They are all positive ions therefore repel each other.
What happens at stage 2 of acceleration?
All the particles have the same kinetic energy
What happens at stage 3 flight tube?
Lighter particles move faster therefore shorter time of flight.
Ke = 1/2mv2
What happens during stage 4 of detection?
+ve ions hits -ve plate ad produce electric current. The electrons move from plate to the ion. The size of current is proportional to number of ions.
How do you gain an electron with the mass spectrum spray?
You take 1 away.
What is the hypodemic needle attached to?
A positive terminal of high-voltage power supply.
