Fig. 4.

HPLC radiochromatograms for a plasma sample spiked ex vivo with standard [¹⁸F]flutemetamol, and for the plasma obtained from a representative subject at b 5, c 30 and d 90 min after administration of flutemetamol (¹⁸F) injection. The vertical axis shows “Radioactivity detector response (mV)” while the “Retention time (min)” appears on the horizontal axis. Region 3 corresponds to the [¹⁸F]flutemetamol parent in b, c and d as identified in a. Regions 1 and 2 correspond to metabolites that are more hydrophilic than the parent of Region 3, and Region 4 represents a minor lipophilic metabolite