Improved methods to determine radionuclidic purity of F-18 compounds

Current revisions of monographs for F-18 pharmaceuticals in the European Pharmacopoeia (Ph. Eur.) (Ph. Eur., 2011) call for a radionuclidic purity (RNP) of or better than 99.9%. However, the current method is not sufficient nor effective for testing this required RNP level.We present a theoretical model leading to a practical procedure for a simple test of RNP for F-18 compounds that tells whether or not the sample is pure with a statistical confidence of 97.5% (P=0.975).

► We examine the method for testing Radionuclidic Purity (RNP) of F-18 compounds.
► The current method is not sufficient for testing the required RNP level.
► We present a simple test that can   determine RNP for F-18 compounds.
► The test answer is given with a statistical confidence of 97.5%.
► Contaminations with half-lives shorter than ∼165min cannot be found for RNP=99.9%.