CHROMATOGRAPHIC DETERMINATION OF THE RADIOCHEMICAL PURITY OF [I-131] METAIODOBENZYLGUANIDINE INFUSION FLUIDS - A COMPARISON AND DISCUSSION OF THE CHROMATOGRAPHIC CHARACTERISTICS USING 3 DIFFERENT TECHNIQUES

This paper proposes a reproducible and validated assay based on solid phase extraction for the determination of the level of free [I-131]iodide in [I-131]metaiodobenzylguanidine infusion fluids. The method has been compared with HPLC and TLC assays. Furthermore, a TLC system is introduced that allows the separation between metaiodobenzylguanidine, its chemical precursor metaiodobenzylamine and iodide. Attention is paid to the chromatographic characteristics of the analytes, with a discussion of the possible retention mechanisms.