title: The influence of temperature on the multiple separation of estrogenic steroids using mobile phases modified with beta-cyclodextrin in high-performance liquid chromatography.
abstract: The effect of temperature on the retention and multiple separation of six estrogenic steroids in reversed-phase liquid chromatography has been studied. Capacity factors (k') of estriol, 17 beta-estradiol, 17 alpha-estradiol, d-equilenin, equilin and estrone were measured using mobile phase modified with different concentrations of beta-cyclodextrin (from 0-16 mM), a fixed solvent composition (acetonitrile-water) and a wide range of column temperatures (from 5 to 80 degrees C). The plots of capacity factors vs. reciprocal of absolute temperature are nonlinear in each case when mobile phase modified with beta-cyclodextrin was used. Particularly strong nonlinearity was observed at lower temperature and at higher beta-cyclodextrin concentration. The complex chromatograms were evaluated using optimization parameters such as capacity factor of the last-eluted peak (k'max), the smallest resolution between adjacent peaks (Rs,min) and relative resolution product (r). The results presented describe precisely the role of temperature in high-performance liquid chromatography systems in which mobile phases modified with cyclodextrin were used. Moreover, the elution order of estrogenic steroids on modified and unmodified mobile phases has been discussed.
authors.affiliation: Medical University of Gdansk, Faculty of Pharmacy, Poland.
authors.forename: P K
authors.initials: PK
authors.lastname: Zarzycki
authors.forename: M
authors.initials: M
authors.lastname: Wierzbowska
authors.forename: H
authors.initials: H
authors.lastname: Lamparczyk
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003505:Cyclodextrins; D004967:Estrogens / Q000302:isolation & purification*; D013696:Temperature; D047392:beta-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D004967:Estrogens; D047392:beta-Cyclodextrins; C031215:betadex