Fichas
mass spectrometry
Fichas del conjunto (18)
- 1What does mass spectrometry determinethe mass of separate atoms or molecules
- 2At first what does mass spectrometry form?ions which are then operated according to their mass to charge ratio
- 3Why is the whole process kept in a vacuumto prevent the ions which are produced from colliding with the air molecules
- 4At the ionisation stage what is the sample dissolved in and forced throughdissolves in a volatile solvent and forced through a hollow needle which is connected to the positive terminal of a high voltage supply.
- 5what does this then producetiny positive charged droplets which have lost electrons to the positive charge of the supply
- 6What then happens to the solvent?the solvent evaporates from the droplets into the vacuum and then the droplets get smaller and smaller until they are no more than a single positively charged ion .
- 7What happens during the acceleration stagethe positive ions are attracted towards a negatively charged plate and accelerate towards it.
- 8what sort of ions achieve a higher speedlighter ions and more high charged ions
- 9what happens during ion driftions pass through a hole in the negatively charged plate forming a beam and travel along a tube to the detector
- 10whats the tube calledflight tube
- 11what is the detection stageions with the same charge arrive at the detector, lighter ones first as they have higher velocities. The flight times are recorded. The positive ions pick up an electron from the detector which causes a current to flow.
- 12what happens at the data analysis stagesignal from the data is passed to a computer which generates a mass spectrum
- 13what can a mass spectrometer be used to identifydifferent isotopes that make up an element
- 14Mass spectrometry detect individual ions so what does this meandifferent isotopes are detected separately because they have different masses
- 15What is high resolution mass spectrometrywhen it can measure relative atomic masses to one five decimal places of an atomic mass unit.
- 16when the work is done to one decimal place what is it calledlow resolution mass spectrometry
- 17how to work relative atomic mass(mass x percentage)/100
- 18what is mass spectrometry used in space forused in space probes to identify elements in rock samples.
Información
- Descripción
- mainly time of flight mass spectrometry
- Creado por
- reegan.oravecz
- Visitas
- 4
- Valoración