Synthesis of Clinical-Grade [¹⁸F]-Fluoroestradiol as a Surrogate PET Biomarker for the Evaluation of Estrogen Receptor-Targeting Therapeutic Drug

Figure 4

Chromatogram of preparative HPLC separation of [¹⁸F]FES reaction mixture. Red-colored trace is radioactivity and blue-colored trace is UV absorbance at 254 nm. The two vertical solid lines in the trace show the start (leftmost, ~14 min) and end (right, ~15 min) of the product collection. Earlier broad radiation peak is due to the close vicinity of radiation detector to the HPLC column. Detector is sensing radiation while the compound is moving inside the column.