One aspect of the present invention relates to a method of purifying radiolabelled compounds comprising a) loading onto a fluorous polymer a radiolabelled compound precursor comprising a fluoroalkyl tin moiety; b) reacting the radiolabelled compound precursor with a radiolabel delivering compound to give a radiolabelled compound, wherein the fluoroalkyl tin moiety is replaced by a radiolabel; and c) eluting the radiolabelled compound from the fluorous polymer.