Molecules, Vol. 28, Pages 4978: Ultrasound-Assisted Extraction, Followed by Gas Chromatography & ndash;Mass Spectrometry for the Simultaneous Quantification of Ethinyl Estradiol and Drospirenone in Contraceptive Formulations

In this study, we have developed the first gas chromatography–mass spectrometry (GC–MS) method for the simultaneous quantification of 17α-ethinyl estradiol (EE) and drospirenone (DP) in contraceptive formulations. Under the final working conditions, analytes were extracted from the solid by ultrasound-assisted extraction (15 min) in methanol. The resulting suspension was diluted in ethyl acetate, subjected to centrifugation and, finally, the supernatant was directly injected into the GC–MS system. No derivatization reagents were utilized. To correct for instrumental variations, calibration was performed using the internal standard method, with cholesterol as the internal standard. A good linearity was achieved throughout the calibration range for both EE (3–12 µg mL−1) and DP (300–1200 µg mL−1), with R2 values exceeding 0.99. Trueness, assessed in terms of percentages of recovery, was also found to be satisfactory for both analytes, with recovery rates of 106 ± 8% for EE and 93 ± 9% for DP. Furthermore, intra-day and inter-day precision studies yielded relative standard deviation values below 6% for both analytes. In terms of sensitivity, the instrumental limits of detection were 0.25 µg mL−1 for EE and 6.6 µg mL−1 for DP, and the instrumental limits of ...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research