INDIRECT PHOTODETECTION OF PREGNANOLONE ON A CYCLOBOND COLUMN BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The chromatographic properties of eight steroids were studied on a Cyclobond column in order to select those which can be used as markers for the indirect photodetection of pregnanolone. Testosterone was shown to be the best compound, enhancing the pregnanolone detection by a factor of 6.5 with respect to the direct detection of pregnanolone at 280 nm under the optimum conditions: 0.0085 mM testosterone with methanol-water (65:35) as mobile phase. The influence of the percentage of methanol and the marker concentration in the mobile phase was studied. The models developed previously on a reversed-phase column were successfully applied and the apparent inclusion constants for progesterone and testosterone in the beta-cyclodextrin cavity were determined. They were 103 and 2200 l mol(-1) for progesterone and testosterone, respectively, with methanol-water (65:35) and 50 and 780 l mol(-1) with methanol-water (75:35) as mobile phase.