Chiang Mai Journal of Science

In this research, reverse-phase high performance liquid chromatography using green mobile phase utilizing short column was developed for the determination of some contraceptive drugs such as ethinyl estradiol (EE), cyproterone acetate (CPA), gestodene (GES) and levonorgestrel (LNG). This Zorbax SB-C18 (12.5´4.6 mm i.d., 5 mm) that commonly used as guard column has been used instead of the expensive and conventional analytical column. The chromatographic behaviors were studied to confirm the performance of this short column and it was found that the reciprocal value of capacity factor of each analyte was linear to micellar concentration. The optimum conditions were 0.05 mol L-1 sodium dodecyl sulfate (SDS) and isopropanol (95:5, v/v) as micellar mobile phase with a flow rate of 1.0 mL min-1. The detection wavelengths were 281, 281, 240 and 240 nm for EE, CPA, GES and LNG, respectively. A green extractant was used in this method instead of organic solvent to extract the analytes. The calibration curves of each contraceptive drug were linear with R2 > 0.9990 and detection limits were 0.003, 0.06, 0.025 and 0.05 mg mL-1 for EE, CPA, GES and LNG, respectively. The proposed method was applied successfully for the determination of contraceptive drugs in oral contraceptive pills. The developed system is not only a green analytical approach but also an effective and inexpensive method for this type of analysis.