試題詳解

(AB) An electron multiplier is a vacuum-tube structure, in which a secondary emission process takes place and a single charge can bombard on secondary-emissive material and induce emission of several ions.

(AC) Among different ion sources for molecular mass spectrometry, the most fragmentation is encountered with electron ionization, which does not produce the most complex spectra, though.

(AD) The selection of sample ions in the quadrupole mass analyzer for detection is only made possible through applying a radio frequency voltage to one fixed pair of rods and a de offset voltage to the other.

(AE) An electric voltage and a magnetic field are needed in both FT ICR and TOF mass spectrometers.

(BC)The resolution of a quadrupole is determined by the ratio of the ac to dc voltage and becomes a maximum when this ratio
is just slightly less than 6.

(BD)ICPMS uses an inductively coupled plasma to separate ions and a mass spectrometer to detect them.