Isolation of norgestrel in contraceptive tablets for use as an analytical standard in its quantification in the aquatic environment

Abstract

Steroidal hormones, natural and synthetic, have become a global concern due to the serious effects they pose to the aquatic environment. Although these hormones are found in low dosage levels in contraceptives, it is the great number of people taking them and the frequency they are taken that makes them available in the aquatic environment to cause problems. As standards were not accessible, laboratory work was done to isolate norgestrel in contraceptive tablets so as to make the standard. This was done so as to quantify it in the aquatic environment. Purity of the standard obtained was tested through melting point analysis, UV and IR spectra determination. Melting point of the standard was found to be 204-207˚C and maximum UV absorbance being at 240nm. The IR spectrum showed all the stretches of the bonds available in norgestrel. Norgestrel was extracted from samples of waste water, Lake Chivero and Chinhoyi waste water as well as treated water from Norton and Chinhoyi municipalities. It was then quantified by using High Performance Liquid Chromatography and UV Vis Spectrophotometer instruments. Values of between 16 and 18ppm of norgestrel was found in waste waters using both HPLC and UV Vis instruments. Also, linearity was observed on calibration graphs with R2 values close to 1. It was found that levels of norgestrel in waste water was higher than that in the treated waters, although this is subject to further research. Similar trend was observed in results from the two instruments used. Liquid Chromatography-Mass Spectrometer can be used in the further research so as to confirm the norgestrel standard that was obtained in the study.