title: An automated SPE-based high-yield synthesis of [11C]acetate and [11C]palmitate: no liquid-liquid extraction, solvent evaporation or distillation required.
abstract: BACKGROUND
  An automated method is described for the rapid and high-yield synthesis of two of the most commonly used radioactive fatty acids: [(11)C]acetate and [(11)C]palmitate.
  
  
  METHODS
  Reaction of [(11)C]CO(2) with the respective Grignard reagents in diethyl ether solution proceeded for 2 min at 40°C. Quenching of the reaction and liberation of nonreacted [(11)C]CO(2) occurred upon addition of a fourfold molar excess of aqueous 0.1 M HCl (acetate) or nonaqueous HCl/Et(2)O (palmitate). Labeled products were then purified by adsorption to an Alumina-N Sep-Pak Plus cartridge and eluted with either aqueous NaH(2)PO(4) solution (acetate) or 100% ethanol (palmitate).
  
  
  RESULTS
  High-performance liquid chromatography analysis confirmed that the radiochemical purity of each product was >98%, and decay-corrected radiochemical yields averaged 33% for [(11)C]palmitate and 40% for [(11)C]acetate.
  
  
  CONCLUSIONS
  The method requires no liquid-liquid extraction, solvent evaporation or distillation capabilities and can be readily adapted to existing radiosynthesis modules.
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202-2111, USA.
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Mock
authors.forename: Clive
authors.initials: C
authors.lastname: Brown-Proctor
authors.forename: Mark A
authors.initials: MA
authors.lastname: Green
authors.forename: Brandon
authors.initials: B
authors.lastname: Steele
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Glick-Wilson
authors.forename: Qi-Huang
authors.initials: QH
authors.lastname: Zheng
mesh_terms: D000085:Acetates / Q000138:chemical synthesis*; D000818:Animals; D002250:Carbon Radioisotopes / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007553:Isotope Labeling / Q000379:methods*; D010168:Palmitates / Q000138:chemical synthesis*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis*; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; D010168:Palmitates; D019275:Radiopharmaceuticals