Figure 3. Deisotoped mass spectra of the discrete m-dPEG®24-NHS ester adducts (top; zero-charge masses of (M•NH3) = 1230.6910 Da and (M•2NH3) = 1247.7180 Da) and mPEG 1K- NHS (SC) (bottom; hydrolyzed NHS ester Ex. C56H111O30 = 1263.7140 Da) and +NH3 adduct series of the intact (Ex. C60H115O32N•NH3 = 1378.7660 Da).
