Purity Determination of Five Typical Endocrine Disrupting Compounds by Differential Scanning Calorimetry

As endocrine-disrupting compounds, 4-octylphenol, 4-nonylphenol, ethinylestradiol, hexestrol, and dienestrol have been detected in water, soil and food, and their certified reference materials are in wide market demand. In this paper, the purity of the five organic compounds was analyzed by differential scanning calorimetry (DSC), and joint research was carried out by high-performance liquid chromatography (HPLC) and thermal gravimetric analysis (TGA). The results showed that the purity of 4-octylphenol, 4-nonylphenol, ethinylestradiol, and hexestrol could be determined by DSC, and the results were in good agreement with those of the HPLC method. Since there was no obvious endothermic curve of dienestrol observed by DSC combined with TGA which revealed the decomposition of dienestrol during melting. It is concluded that the DSC method is not applicable for the purity analysis of dienestrol.