Figure 2.
RP-HPLC chromatograms of the IMP466 18F-labeling mix (panel A) and the purified 18F-IMP466 (panel B). Red traces represents radioactivity(left y-axis) and blue traces represents UV signal (right y-axis). In the HPLC chromatogram of the crude mixture, unbound “Al18F” eluted with the void volume (Rt = 0.8 min). Two radioactive peaks correspond to the stereoisomers of radiolabeled peptide times (Rt = 17.4 and Rt = 19.8 min). Finally, the unlabeled IMP466 was present in the UV channel (Rt = 21.4 min). After purification, only two radioactive peptide peaks are observed, indicating the formation of two stereoisomers.