isotope pattern

in mass spectrometry
https://doi.org/10.1351/goldbook.I03330
Set of peaks related to ions with the same chemical formula but containing different isotopes; e.g. the 16 and 17 mass/charge peaks in a CH4 sample arising from 12CH4+ and 13CH4+ ions.
Source:
PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2198 (https://doi.org/10.1351/pac199062112167)