Structure-retention relationships of steroid hormones in reversed-phase liquid chromatography and micellar...

Quantitative structure-retention relationship (QSRR) studies are useful in retention prediction, finding the relevant structural descriptors for analytes and estimating the relative biological activities of a series of analytes. Most of the studies have been conducted by RP-HPLC and a few by micellar electrokinetic capillary chromatography (MECC). The aim of this work was to find structural parameters and characteristics related to the RP retention and electrophoretic migration of steroids in order to predict the retention/migration of steroid hormones on the basis of their molecular structure. Retention data were obtained with an ODS column using a mobile phases aqueous methanol-acetonitrile (mobile phase A) and methanol-tetrahydrofuran (mobile phase B). MECC was conducted with a sodium dodecyl sulfate (SDS)-borate system and with a mixed micellar solution of SDS and sodium cholate. Several topological indices, such as the connectivity indices, chi, were used as structural parameters. Steric factors seem to have a great effect on the retention of steroid hormones, especially with the MeCN-containing mobile phase. Retention in mobile phase B could be predicted more accurately. Topological indices can be used in the modelling and prediction of the retention/migration of steroid hormones when the solutes form a congeneric series and stereochemical properties do not govern the separation process.