Synthesis of no-carrier-added [F-18]fluoroacetate

To synthesize no-carrier-added potassium [F-18]fluoroacetate, O-mesyl glycolate ethyl ester and O-tosyl glycolate ethyl ester were synthesized as precursors. These precursors were radiolabeled by reacting with dried tetrabutylammonium [F-18]fluoride in the presence of tetrabutylammonium bicarbonate. O-Mesyl glycolate ethyl ester showed higer F-18 incorporation (77.6% at 100 degrees C) than O-tosyl glycolate ethyl ester (63.2% at 100 degrees C). Resulting [F-18]fluoroacetate ethyl ester was hydrolyzed quantitatively by heating in 1 M potassium hydroxide solution. The [F-18]fluoroacetate was adsorbed to strong anion exchange resin and washed with excess water. Following elution with 1 M sodium bicarbonate solution and passing through Sep-Pak neutral alumina column, the [F-18]fluoroacetate was obtained with 24.5% recovery (non-decay-corrected). Total labeling time from drying F-18 to final product was 70 to 90 min.