Introduction: Analysis of the radioactive components in plasma taken during positron emission tomography (PET) measurements is often vital for the correct quantification of the PET data. The described high-performance liquid chromatography (HPLC) method has been developed to provide a fast, sensitive and robust method for the measurement of plasma samples from PET studies using [(11)C]-labeled radiopharmaceuticals.
Methods: Unadulterated plasma samples were analyzed directly, following a simple filtration, by the use of a small extraction column, containing a restricted access material, combined with a monolithic analysis column in a column-switching HPLC system.
Results: Up to 4 ml of plasma was analyzed by this method within 4.5-7 min in a fully automated process. Because of the rapid analysis, a large number of samples could be analyzed during a 90-min PET scan. The extraction column could be used for analysis of up to 500 ml of plasma before replacement was required.
Conclusions: The described method is fast and robust and the large sample volumes allow for accurate determination of the radioactive components in plasma even at 90 min after injection of a [(11)C]-labeled radiopharmaceutical.