Figure 4.

(A): UV-HPLC chromatograms (288 nm) of reference fluorinated compounds (S)-37, (S)-38 and (S)-39; (B): Radioactivity-HPLC chromatograms of the corresponding radiotracers (S)-[¹⁸F]37 ([¹⁸F]5-fluoro-L-TIC(OH)), (S)-[¹⁸F]38 ([¹⁸F]6-fluoro-L-TIC(OH)) and (S)-[¹⁸F]39 ([¹⁸F]8-fluoro-L-TIC(OH)) obtained after semi-preparative RP-HPLC purification and formulation. The radioactivity detector was connected in series after the UV detector accounting for the slight difference in retention times (≈0.3 min) observed between ¹⁸F and ¹⁹F products.