N-ethyl iodoacetamide-d5 90.08414459228515625 90.08414459228515625 90.1399993896484375 90.1399993896484375 artifact none NEIAA:2H(5) modification from Unimod Isotopic label C 4 H 2 (2)H 5 N 1 O 1 N-ethyl iodoacetamide-d5 MOD:00562 C 4 H 2 (2)H 5 N 1 O 1 PSI-MOD X (2)H deuterium tagged reagent