partial isotopic scrambling

https://doi.org/10.1351/goldbook.12514
Partial random mixing of isotopes among specified atom positions in an ion or neutral species.
Note: In mass spectrometry, this term usually refers to the partial random mixing of isotopes in isolated ions that were formed with a fixed isotopic composition.
Source:
PAC, 2013, 85, 1515. (Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)) on page 1574 [Terms] [Paper]