(a) IsoP method
(b) NP method
Figure 1: Comparison on the patterns of chromatograms at m/z 569.4 for the H-CSF sample processed for F2-IsoPs (IsoP method) and for F4-NPs (NP method). Because the amount of samples and internal standard used were different for different methods, the abundance of peaks for the internal standard at m/z 573.4 was also shown. The peaks of F2-IsoPs and [2H4]-15-F2t-IsoP at m/z 569.4 and m/z 573.4, respectively, are indicated by the asterisks.