Determination of medroxyprogesterone in water samples using dispersive liquid-liquid microextraction with low solvent consumption

A simple, rapid and efficient extraction procedure, dispersive liquid-liquid microextraction with low solvent consumption, has been developed in combination with high-performance liquid chromatography-ultraviolet detection for the extraction and determination of medroxyprogesterone from aqueous samples. For this technique, 120 mu L of the mixture of extraction solvent and dispersive solvent at a ratio of 3:7 was injected into the aqueous sample with a syringe. Then a cloudy solution forms while manually shaking the conical centrifuge tube. After centrifuging, the extractant settled at the bottom of the conical centrifuge tube and part of it was introduced into the HPLC system. Some key parameters, including the type and volume of extraction solvent and dispersive solvent, extraction time and salt effect were investigated. Under optimum conditions, good linear behavior (R > 0.9982) over the investigated concentration ranges were obtained. The method was successfully applied to tap water, farm water and river water samples.