title: Faster and easier radiochemical purity testing for [125I]sodium iothalamate.
abstract: A previous method for determination of the radiochemical purity (RCP) value of [125I]sodium iothalamate uses two paper strips and solvents (total developing time is approximately 2.5 h). To simplify and shorten the RCP testing procedure, our laboratory has developed a single-strip chromatography method that not only distributes free 125I and [125I]sodium iothalamate to different relative front (Rf) locations, but is also faster and easier to perform. RCP of [125I]sodium iothalamate was determined with the use of a 10-cm instant thin-layer chromatography strip impregnated with polysilicic acid gel (ITLC-SA) as the solid phase, and a mobile phase of 2-butanol:acetic acid:water (140:2.5:70, v/v). By using autoradiography and counting the strip segments in a gamma counter, our results indicated that free 125I migrated to Rf = 0.89-1.00 while the [125I]sodium iothalamate moved to Rf = 0.44-0.67. The total developing time for the single-strip ITLC-SA system was approximately 1 h.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Bush
authors.forename: J E
authors.initials: JE
authors.lastname: Coughlin
authors.forename: T J
authors.initials: TJ
authors.lastname: Herold
authors.forename: J C
authors.initials: JC
authors.lastname: Hung
mesh_terms: D001345:Autoradiography; D002855:Chromatography, Thin Layer; D003287:Contrast Media / Q000032:analysis*; D007457:Iodine Radioisotopes / Q000032:analysis*; D007483:Iothalamic Acid / Q000032:analysis*; D011786:Quality Control; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007457:Iodine Radioisotopes; D007483:Iothalamic Acid