FIGURE 4. HPLC of methanol-water layer after incubation of 18F-FECh with Ehrlich ascites tumor cells. No-carrier-added 18F-FECh chloride was incubated with Ehrlich ascites tumor cells (approximately 106 cells/mL) in glucose-fortified Hanks’ solution for 30 min. Methanol-water–soluble component was separated from incubated cells and divided into halves. One half was analyzed on HPLC using cation-exchange resin and other half was analyzed on HPLC using anion-exchange resin. 18F radioactivity was measured in every fraction.
