Simple isocratic high-performance liquid chromatographic method for measurement of iodixanol in human plasma.

A simple isocratic high-performance liquid chromatographic method was developed for the determination of iodixanol in human plasma. Samples containing an internal standard were prepared for analysis using a simple clean-up procedure based on Sep-Pak C18 solid-phase extraction and chromatographed using a size-exclusion column with purified water as a mobile phase. The iodixanol peak was completely separated from the peaks of an internal standard and endogenous substances on this column. Three geometric isomers (exo-exo, endo-exo and endo-endo forms) of iodixanol could be eluted as a single peak. The method was found to be applicable to pharmacokinetic studies of iodixanol in human plasma.