has value type peak isotopomer peak true OBSOLETE Identifies a peak when no de-isotoping has been performed. The value slot reports the isotopomer peak, e.g. '2H', '13C', '15N', '18O', '31P'. This term was obsoleted because it was replaced by the more exact terms MS:1002956 'isotopic ion MS peak', MS:1002957 'isotopomer MS peak' and MS:1002958 'isotopologue MS peak' instead. MS MS:1002897