Separation of steroids by micellar electrokinetic capillary chromatography with sodium cholate

Several steroid hormones that are routinely determined in clinical settings are resolved by micellar electrokinetic capillary chromatography (MECC) in phosphate buffer (pH = 7.4, 15 kV). These steroidal compounds are separated by MECC within a short time under physiological conditions via the use of bile salt surfactant (0.04M sodium cholate) in conjunction with an appropriate organic modifier (20% methanol). The elution patterns of seven steroid hormones are determined within 9 min with a voltage of 30 kV. The effect of varying the percentage of added methanol modifier, the applied voltage, and the temperature on the migration behavior of the steroids is examined.