Figure 2: Chromatograms at m/z 569.4, m/z 573.4, and m/z 593.5 for the M-CSF sample processed for F4-NPs analysis and the 4 subsequent injections of undecane alone (Wash-1 to Wash-4). The chromatograms in the range of 3.6 min to 8.6 min (the end of data acquisition) were compared. The peak of F2-IsoPs is indicated by the arrow. The peak of [2H4]-15-F2t-IsoP is indicated by the asterisk. Peak and peak indicated in the text were peaks of the retained substances from the sample with very high abundance. The range of retention time for quantification of F4-NPs peaks at m/z 593.5, which is defined by that for the peaks of oxidized DHA, is indicated by the brace.