title: [Separation of levonorgestrel, progesterone and testosterone by micellar electrokinetic capillary chromatography].
abstract: Separation of levonorgestrel, progesterone and testosterone was achieved by using micellar electrokinetic capillary chromatography (MECC). A column of 53 cm (to the detector) x 50 microns i.d. uncoated fused-silica capillary (totally 68 cm in length) and an ultra-violet detector with fixed wavelength at 254 nm were used throughout all the experiments. MECC analysis was optimized by evaluating three different micelle-forming agents, the concentration of SDS and several of organic additives in a 10 mmol/L borate running buffer (pH 9.2). Complete separations were obtained with either 10%-20% acetonitrile or 20 mmol/L 2,6-dimethyl-beta-cyclodextrin (DM-beta-CD) as the modifier in buffer. When the acetonitrile volume fraction was in the range of 0-15%, the migration times of the three steroids increased with the acetonitrile volume fraction, but in the range of 15%-20% acetonitrile concentrations, the situation was opposite. This behavior of the steroids was attributed to the interaction of two opposite effects, an increased mobility due to decreased partition coefficient and a decreased electroosmotic flow (EOF). Both beta-cyclodextrin (beta-CD) and gamma-cyclodextrin (gamma-CD) were found to be inadequate for a satisfactory separation.
authors.affiliation: National Research Institute for Family Planning, Beijing, 100081.
authors.forename: Q
authors.initials: Q
authors.lastname: Xu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Gu
authors.forename: X
authors.initials: X
authors.lastname: Chen
mesh_terms: D020374:Chromatography, Micellar Electrokinetic Capillary; D003505:Cyclodextrins; D016912:Levonorgestrel / Q000302:isolation & purification*; D011374:Progesterone / Q000302:isolation & purification*; D013739:Testosterone / Q000302:isolation & purification*; D047392:beta-Cyclodextrins; D047408:gamma-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D047408:gamma-Cyclodextrins; D013739:Testosterone; D011374:Progesterone; D016912:Levonorgestrel; C031215:betadex; C023792:gamma-cyclodextrin