has material input material output of role of has role ion material output role mass spectrometry role product ion role product Ion formed as the product of a reaction involving a particular precursor ion. [IUPAC] product ion role K. K. Murray, R. K. Boyd, M. N. Eberlin, G. J. Langley, L. Li and Y. Naito, Pure Appl. Chem., 2013, 85, 1515-1609 product ion precursor ion role ion role process