The resulting fragments are usually a- and x-type product ions.

This population is then fragmented to yield product ions whose signal abundances are indicative of the abundance of the peptide in the sample.

The application of selected reaction monitoring to multiple product ions from one or more precursor ions.

From this spectrum, one can select a prominent product ion which can be the product ion for the chosen precursor ion.

Associative ionization is a gas phase reaction in which two atoms or molecules interact to form a single product ion.

The product ion is selected in the second mass analyzer, and the precursor masses are scanned in the first mass analyzer.

Note that precursor ion is synonymous with parent ion and product ion with daughter ion; however the use of these anthropomorphic terms is discouraged.

If the product ions persist in their non-equilibrium state for a moderate amount of time before auto-dissociation this process is called metastable fragmentation.

Liberation of the electric potential energy results in fragmentation of the product ion.

The product ions and rate coefficients have been derived in this way for well over 200 volatile compounds, which can be found in the scientific literature.