Answer to Question #154930 in Bioinformatics for vaibhav

Question

(a) Why must the inside of a spectrometer kept at a high vacuum?

(b) How are molecular ions formed? What information could be obtained from

mass/charge value of a molecular ion?

(c) Define Ion Trap, ICR, Quadrupole and Octapole.

Answer 1

a) Inside of a spectrometer must be kept at a high vacuum since ions must travel in continuous paths towards the detector. If there were gaseous atoms in the mass spectrometer chamber, they might impede the travel of the ions.

b) Molecular ions are formed by the removal from positive ions or addition to negative ions a molecule of one or more electrons without fragmentation of the molecular structure. Information about how to find the relative formula mass (relative molecular mass) from it mass spectrum could be obtained from mass/charge value of a molecular ion.

c) Ion Trap is a combination of electric or magnetic fields used to capture charged particles. That is, ions often in a system isolated from an external environment.

ICR - instantaneous center of rotation is the point fixed to a body undergoing planar movement that has zero velocity at a particular instant of time.

Quadrupole is a type of ion trap that uses dynamic electric fields to trap charged particles.

Octupole is anything having eight poles or electrodes, especially a kind of magnet used for controlling beams of charged particles.