RESUMO
The effect of varying the operating temperature from 6 to 90 degrees C on the chromatographic performance of the exo-exo and exo-endo isomers of the X-ray contrast agent lodixanol in packed-capillary reversed-phase liquid chromatography shows increasing interconversion rates between the two isomeric conformers with increasing temperature. At 90 degrees C, Iodixanol elutes as one sharp peak due to an increased interconversion rate between the two isomeric conformers. Consequently, increased sensitivity is achieved. Temperature programming from 6 to 40 degrees C is utilized to optimize the resolution and determination of the exo-exo and exo-endo isomers. Temperature programming provides a significant decrease in the retention times in comparison with the isothermal separations while still preserving baseline separation of the isomers.
