I'm working with peptides.
I've got a problem with one of them. During the analysis by LCMS, some adducts have emerged with a difference of +111 mass units
This peptide is TFA salt and the mobile phases are 0.1%TFA/H2O and 0.1%TFA/CH3CN.
I am convinced that these adducts ions are created by the TFA but usually, TFA cause a mass difference of +96 (+TFA with -H2O) or just +114 (+TFA). Maybe i'm wrong...
Does anyone have had this type of adducts?
Does anyone know the answer?
Thanks for reply.