Fig. 5.

(A) Comparison of released 2-AB labelled N-glycan from trastuzumab drug product. Quantitation was obtained integrating fluorescence trace (orange) and MS signals from each N-glycan (blue). Quantitation is based on triplicate sample preparation. *In 2-AB trace coeluting A2G1 and A1G1F N-glycans were quantified as a single peak. (B) Comparison of released N-glycan from trastuzumab drug product. Quantitation was obtained from fluorescence trace after labelling with 2-AA (yellow) and 2-AB (purple). Quantitation is based on triplicate sample preparation. **In 2-AB labelled N-glycans M5 elutes at a different retention time, and relative percentage is only relative to coeluting A2G1 and A1G1F species.