Zusammenfassung der Ressource
Mass Spectrometer
- Vaporisation
- Atoms must be vaporised to be to be turned into
their gaseous state, if not in it's gaseous state
already.
- Ionisation
- A beam of e- from an "e- gun" knocks out
e-'s from atoms or molecules so they can
become +ve ions
- Acceleration
- The +ve ions are attracted towards
-vely charged plates and are
accelerated to a high speed. The lighter
the ions, the faster they go. Some ions
pass through slits in the plates, forming
the ions into a beam.
- Deflection
- Beam of ions moves into magnetic field at right
angles to the direction of travel. Magnetic field
deflects beam of ions into an arc of a circle. The
deflection of an ion depends on the mass to
charge (m/z). Heavier ions are deflected less than
lighter ones. The deflection also depends on the
magnetic field strength. The stronger the field, the
greater the deflection.
- Detection
- The magnetic field is gradually
increased, so the ions of increasing
mass enter the detector one after
another. Ions strike the detector,
accept electrons, lose their charge,
and create a current - proportional to
the abundance of each ion.