fragmentation reaction

in mass spectrometry
A @F02506@ reaction may be written: \[\text{M}_{1}^{+}\rightarrow \text{M}_{2}^{+}+\text{M}_{3}\] The @D01547@ of a @M03872@ ion of mass-to-charge ratio \(\frac{m_{1}}{z_{1}}\) into an ion of mass-to-charge ratio \(\frac{m_{2}}{z_{2}}\) after electric @A00051@ of the @M03872@ ion and before magnetic deflection gives rise to a peak in the @M03749@ at an apparent mass, \(\frac{m_{2}^{2}\ z_{1}}{m_{1}\ z_{2}^{2}}\). The symbol \(m^{*}\) should be used to indicate the apparent mass of the product ions giving rise to this peak. Traditionally, the peak itself has been called a @M03872@ peak and this should preferably be expressed as @M03874@ peak. It is nevertheless recommended that the former term should be retained. The word @M03872@ should never be used as a noun. Its use as an adjective should be limited to such terms as @M03872@ ion, where it is used correctly, and to the special case of @M03872@ peak discussed above. It should never be used in such terms as @M03872@ reaction, @M03872@ @D01547@, @M03872@ studies, etc. It should be clear that the @M03872@ ion is the ion that undergoes @F02506@; it is not detected. When a reaction is written with an asterisk above the arrow as shown: \[\text{M}_{1}^{+}\overset{\text{*}}{\rightarrow }\text{M}_{2}^{+}+\text{M}_{3}\] this means that the reaction has been confirmed by the observation of a @M03872@ peak. The textual description of such a process may be written as, for example, (\(m^{*}\), \(43\rightarrow 28\), calcd. 18.2, obsd. 18.3) meaning 'for the @F02506@ \(\frac{m}{z}\ 43\rightarrow \frac{m}{z}\ 28\) a @M03872@ peak at \(\frac{m}{z}\) 18.3 (calculated 18.2) has been observed'.
PAC, 1991, 63, 1541. (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1557 [Terms] [Paper]