Estrogens as a kind of steroidal sex hormone are widely used in humans, especially quinestrol(QS),dienestrol(DS) and norethindrone(NET, 19-nor-17-alphaethinltestoster-one), which cannot be completely degraded after application. Steroidal estrogens at low concentration pulling into environment can disturb the normal biological function of wide life and thus lead to great threat to humans. So it is important to explore its degradation mechanism and its behavior in the environment. In this study, we investigated the oxidation or reduction system under gamma irradiation for reducing estrogenic activity in the aqueous solutions as well as degradation kinetics, its by-products and yield of transformation by different analytical methods such as GC–MS and HPLC. Gamma irradiation could effectively degrade estrogens in aqueous solution. The degradation reaction of estrogens could be depicted by first-order reaction kinetics. The total organic carbon of solution decreased with an increasing absorbed dose with the order: quinestrol [ norethindrone [ dienestrol. The toxicity of the three estrogens was declined after irradiation. Mono- and quadric-hydroxylated intermediates as well as organic acids were formed after gamma irradiation.
Estrogens as a kind of steroidal sex hormone are widely used in humans, especially quinestrol (QS), dienestrol (DS) and norethindrone (NET, 19-nor-17-alpha- ethinltestoster-one), which cannot be completely degraded after application. Steroidal estrogens at low concentration pulling into environment can disturb the normal biological function of wide life and thus lead to great threat to humans. So it is important to explore its degradation mechanism and its behavior in the environment. In this study, we investigated the oxidation or reduction system under gamma irradiation for reducing estrogenic activity in the aqueous solutions as well as degradation kinetics, its by-products and yield of transformation by different ana- lytical methods such as GC-MS and HPLC. Gamma irra- diation could effectively degrade estrogens in aqueous solution. The degradation reaction of estrogens could be depicted by first-order reaction kinetics. The total organic carbon of solution decreased with an increasing absorbed dose with the order: quinestrol 〉 norethindrone 〉 diene- strol. The toxicity of the three estrogens was declined after irradiation. Mono- and quadric-hydroxylated intermediates as well as organic acids were formed after gamma irradiation.