Fragmentation pattern coefficient - ESCO, Ltd.

Fragmentation pattern coefficient

The desorbed gases are ionized by the accelerated electrons emitted from the filament of the quadrupole mass spectrometer (QMS).

Since the accelerated electrons have a large energy, cleavage occurs for some of the ions.

For example, the following ions are generated from water (H₂O): H₂O⁺, OH⁺, O⁺, H⁺. The molecules that are simply ionized (H₂O⁺) are called molecular ions. The ions generated by cleavage of the H₂O⁺ (OH⁺, O⁺, H⁺) are called fragment ions.

The ratio of molecular ions to fragment ions generated under the same conditions is a fixed value.

Fragmentation pattern coefficient

* The fragmentation pattern coefficient varies slightly depending on the ionization energy and the mass spectrometer.