DeltaMass linker attached to peptide in Fmoc peptide synthesis From DeltaMass: Average Mass: 162 Average Mass Change:162 Notes: (from the ABRF discussion list archive) There may be ... things in the reagent K that would allow cleavage of the peptide to occur at the wrong place...in this case it removes the dimethoxybenzyl group first inactivating that site for cleavage, and it goes after tne next amide bond closer to the resin. Try the TFA/TIS/water/EDT cocktail...TFA = 92%, TIS =3%, and water is at 5%. .. had this issue on longer peptides.. and by increasing the amount of water a little bit... able to elminate this problem. MOD:01067 PSI-MOD artifact modification from DeltaMass