Patent ID: 7897935

Claim:
A method for use in an apparatus for purifying the product of a reaction to synthesise a radiopharmaceutical compound, wherein the apparatus includes a chromatography separating device, a UV-absorption detector located at a UV-monitoring location, a radioactivity detector located at a radioactivity monitoring location, and a collection container having a collection inlet valve located at a collection location, the method comprising: determining a first eluent propagation time between the UV-monitoring location and the radiation-monitoring location; determining a second eluent propagation time from at least one of the UV-monitoring location and the radioactivity-monitoring location to the collection location; passing the synthesis product through the chromatographic separating device to produce a corresponding eluent; monitoring UV-absorption of the eluent to identify a first time period in which a substantially pure sample of the radiopharmaceutical compound is present at the UV-monitoring location; monitoring radioactivity of the eluent to identify a second time period in which a substantially high concentration of the radiopharmaceutical compound is present at the radioactivity-monitoring location; determining a third time period in which a substantially pure sample of the radiopharmaceutical compound is present at the collection location in a substantially high concentration, based upon said first time period, said second time period, said first eluent-propagation delay, and said second eluent-propagation delay; and opening the collection inlet valve during the third time period to collect the purified radiopharmaceutical compound in the collection container.