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.