Methanol, acetonitrile (HPLC grade) and ethanol (HPLC grade) were purchased from Rathburn Chemicals UK Ltd. All the reagents, ammonium tetrafluoroborate, anhydrous acetonitrile, and anhydrous methanol were purchased from Sigma Aldrich (UK). Sep-Pak Accell Plus QMA Carbonate Plus Light Cartridge (46 mg of sorbent per cartridge, 40 μm particle size), Sep-Pak alumina N Plus Light Cartridge, Oasis WAX Plus short cartridge (225 mg sorbent per cartridge, 60 μm particle size), and Sep-Pak Florisil Plus Light Cartridge were purchased from Waters UK. 0.9 % saline was purchased from Greater Glasgow & Clyde NHS Pharmacy Distribution Centre. All Sep-Pak cartridges were used without prior conditioning.
Boron trifluoride acetonitrile complex solution, 15.2–16.8% BF3 basis; boron trifluoride-methanol solution, ~ 10% (~ 1.3 M), for GC derivatization; boron trifluoride dihydrate, 96% and aqueous ammonium hydroxide (25%) were purchased from Sigma-Aldrich. Precursors for [18F]TFB radiolabelling were diluted in an anhydrous solvent to the desired concentration as described in the "Results " and Discussion " sections. To obtain 1/500 dilution 3 µL of 10% boron trifluoride methanol solution was withdrawn from the original 10 mL shipment bottle by means of the 10 µL glass GC syringe and dissolved in 1500 µL of anhydrous acetonitrile in a sealed 2mL glass HPLC sample vial.
Boron trifluoride acetonitrile complex solution, 15.2–16.8% BF3 basis; boron trifluoride-methanol solution, ~ 10% (~ 1.3 M), for GC derivatization; boron trifluoride dihydrate, 96% and aqueous ammonium hydroxide (25%) were purchased from Sigma-Aldrich. Precursors for [18F]TFB radiolabelling were diluted in an anhydrous solvent to the desired concentration as described in the "