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

Figure 6

Typical HPLC chromatogram of [¹⁸F]FES product. (a) showed radiation peak of the [¹⁸F]FES product without coinjection of authentic standard. (b) showed UV absorbance at 280 nm of [¹⁸F]FES product along with coinjected authentic standard FES. (c) showed radiation peak of the co-injection. There is tubing between the UV and radiation detectors so that the FES is eluted at ~9.3 min for UV and ~9.5 min for radiation. UV peaks before 4 min are the UV absorption of formulation buffer of the product and acetonitrile solvent for authentic standard.

(a)

(b)

(c)