Ion-attachment mass spectrometry is a form of mass spectrometry that uses a "soft" form of ionization similar to chemical ionization in which a cation is attached to the analyte molecule in a reactive collision: M + X + + A ⟶ MX + + A {\displaystyle {\ce {{M}+ {X+}+ A -> {MX+}+ A}}} Where M is the analyte molecule, X+ is the cation and A is a non-reacting collision partner. {MX+}+ A}}} Where M is the analyte molecule, X+ is the cation and A is a non-reacting collision partner." data-audio-language="EN"> Wikipedia