Masss Spectrometry

Created by: samya_
Created on: 18-12-17 13:56

what are the 6 stages of TOF mass spectrometry

1) vaporization/Vaccum 2) IONISATION 3)ACCELERATION 4)ION DRIFT 5)DETECTION 6)DATA ANALYSIS

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Explain Stage 1 Vaporisation/vaccum?

Sample vaporised so can't trave through tof mass spectrometer *whole apparatus kept under vacuum so no air is present. This stops ions formed in apparatus from collliding with molecules in air

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Explain stage 2 ionisation?

Sample passed through nozzle making "high pressure jet" Highg voltage passed causing loss of an electron.high vol causes each particles to gain h+ ion A gaseous positive charged sample produces. We call this 'ELECTROSPRAY IONISATION

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explAIN electron impact ionisation, WHICH IS ANOTHER METHOS DIFFERENT TO E;ECTROSPRAY IONISATION

THE SAMPLE IS VAPORISED AND AN 'ELECTRON GUN' IS USED TO FIRE HIGH ENERGY ELECTRONS ON IT THIS KNOCKS ONE ELECTRON OFF EACH PARTICLE, SO THYE BECOME +1 IONS

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Explain stage 3 acceleration

Positve ions passed through an electric field. Lighter ions accelerate faster . The positive ions are all accelerating towards the negatively charged plate

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Explain stage 4 ion drift?

Ions Enter region with no electric field so just drift through. The particles travel through with constant speed and KE

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Explain stage 5 detection?

Ions detected as electric current is made when the pos particles hit neg plate . Lighter ions reach ion detecter first

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Explain stage 6 data analysis?

Info from detector sent to computer which produces mass spectrum

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What is relative atomic mass?

The average mass of an atom of an element on a scale where an atom of carbon-12 is 12

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What is the relative isotopic mass?

Info from detector sent to computer which produces mass spectrum

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What does the relative abundance show?

The proportion of each isotope present in the sample

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Other cards in this set

Card 2

Front

Explain Stage 1 Vaporisation/vaccum?

Back

Sample vaporised so can't trave through tof mass spectrometer *whole apparatus kept under vacuum so no air is present. This stops ions formed in apparatus from collliding with molecules in air

Card 3

Front

Explain stage 2 ionisation?

Back

Card 4

Front

explAIN electron impact ionisation, WHICH IS ANOTHER METHOS DIFFERENT TO E;ECTROSPRAY IONISATION

Back

Card 5

Front

Explain stage 3 acceleration

Back

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Masss Spectrometry