Changes were made to the automated sequence and cassette layout in order to ensure elution of [ 18 F]FSPG during the automated process (Fig. ). Rather than eluting the [ 18 F]FSPG through the two MCX cartridges, as illustrated in Fig. , the PBS was passed backwards through the MCX cartridges, eluting the radiotracer back off of the top of the cartridge it was loaded on to in a 'reverse elution' (Fig. ). Furthermore, to improve the trapping efficiency of the solid phase extraction, the loading speed of the crude product from the external quenching vial and all subsequent washing and elution steps were reduced from 76 mL/min (the pre-set speed of the syringe FASTlab syringe drives) to 7 mL/min. As the syringe driver could not be directly controlled, this slower elution was achieved by breaking down the syringe movement into multiple programmed stop/start commands (12 × 5 second intervals were used for syringe 2 and 3, with a total volume of 7 mL). These adjustments to the automation resulted in a fully automated synthesis and isolation of [ 18 F]FSPG with an improved radiochemical purity (RCP) of 94%, although the isolated RCY was low, at 6.8% (Table , Entry 2).