Purification method

Abstract

The invention relates to methods and apparatus for purifying a radiolabelled compound. The method comprises (i) passing a crude reaction mixture comprising the desired radiolabelled compound and one or more contaminants in a solvent through a narrow bore vessel at elevated temperature such that the organic solvent and either the radiolabelled compound or one or more contaminants is vaporised forming a vaporised component, and (ii) collecting the resulting vaporised component by condensing into a collection vessel.

What is claimed is: 
     
         1 .- 8 . (canceled) 
     
     
         9 . Apparatus for purifying a radiolabelled compound which comprises a narrow bore vessel containing a crude reaction mixture which crude reaction mixture comprises the desired radiolabelled compound and one or more contaminants in a solvent, wherein the internal diameter of the narrow bore vessel is in the range of about 1 micrometre to 1.5 mm and wherein the radiolabelled compound has a boiling point of 200° C. or more. 
     
     
         10 . Apparatus according to  claim 9  wherein the narrow bore vessel is an HPLC loop with no solid support packing. 
     
     
         11 . Apparatus according to  claim 9  wherein the internal diameter of the narrow bore vessel is 40 to 200 μm. 
     
     
         12 . Apparatus according to  claim 9  wherein the radiolabelled compound is a radiolabelled tracer is either a [ 18 F]-tracer wherein said [ 18 F]-tracer is-[ 18 F]-FDG, [ 18 F]-FLT, [ 18 F]-FET, [ 18 F]-FES, or [ 18 F]-FHBG, or a [ 11 C]-tracer wherein said [ 11 C]-tracer is [ 11 C]-PIB, [ 11 C]-CFT, [ 11 C]-Raclopride, or [ 11 C]-thymidine.