Optimization of the reaction conditions quickly increased both RCY and RCP (Table ). After adjustment of the reaction temperatures and reaction mixture volumes, [ 18 F]FSPG was obtained 31 ± 4% (n = 6) RCY and >96% RCP. Subsequently, optimization of the automated process focused on decreasing the synthesis time. Careful adjustment of the elution flow rate and reduction in the volume of water used to wash the cartridge-bound radiotracer reduced the synthesis time by 18 min without compromising on the RCP (>96%) and led to an improved RCY of 38.4 ± 2.6% (n = 3).