Biomolecular Mass Spectrometry: Applications to Proteins and Peptides - Molecules: Nucleation, Aggregation and Crystallization - page 57

Quadrupole MS

ToF-MS

Hexapole
(Ion Bridge)

Z SPRAY
ion source

Quadrupole
(Ion Bridge)

Hexapole
(Ion Bridge)

MS-MS

REFLECTRON

Fig. 2. The QToF is one of the most versatile configurations for biological mass spec-
trometry. It combines a quadrupole mass filter and a hexapole collision cell with a ToF
analyzer, which allows MS/MS for de novo sequencing and dissociation experiments on
non-covalent complexes. Arrows indicate the trajectory of the ions into the spectrometer.

detects the ions that are separated in the mass analyzer. One of the most
common detectors is the multi-channel plate detector, which is closely
related to electron multipliers. When ions hit the detector, the second-
ary ions produced are accelerated into the continous dynode electron
multiplier, resulting in an electron cascade that gives rise to a measur-
able current at the end of the electron multiplier (de Hoffmann,
Stroobant, 2002).

Proteomics

The most prominent role of MS in biological research today is in the post-
genomic arena. The genome is a mere blueprint of a vastly complex net-
work of interactions orchestrated principally by proteins. The protein
complement of the genome is what we refer to as the proteome and the