Liu Ze-hua, Kanjo Yoshinori, Mizutani Satoshi
Department of Urban Engineering, Graduate School of Engineering, Osaka City University, Sumiyoshi-ku, 558-8585, Osaka, Japan.
J Environ Monit. 2010 Aug 5;12(8):1594-600. doi: 10.1039/c002952a. Epub 2010 Jun 17.
Deconjugation reactions of natural estrogen conjugates were studied here by three different solutions of 1 M hydrochloric acid (HCl) in methanol. Estrogen sulfates could be easily deconjugated even at low temperature, while deconjugation conditions of estrogen glucuronides required a higher temperature and longer time. For 1 M HCl in methanol with 8% water, the deconjugation efficiencies of the three studied estrogen glucuronides were below 59.4% at 80 degrees C for 360 min, while the corresponding deconjugation efficiencies were above 80.6% for anhydrous HCl methanol at 80 degrees C for 210 min, which suggested trace water in the solution of 1 M HCl methanol retarded the deconjugation rates of estrogen glucuronides. On the other hand, their corresponding deconjugation rates increased with the addition of ethyl acetate, and their corresponding deconjugation efficiencies were above 86.7% at 80 degrees C for 120 min. As water is a highly polar solution, and the polarity of ethyl acetate is lower than that of methanol, this may suggest that a low polar substance would favor the reaction, while a highly polar solution would prohibit the reaction. All reactions were in pseudo first-order, and higher temperature increased the reaction rate. Finally, a GC-MS method for simultaneous analysis of free estrogens and estrogen conjugates in wastewater with acid-catalyzed solvolysis was developed, and satisfactory recovery efficiencies were obtained by spiking the standard target chemicals into the influent and effluent of one municipal wastewater treatment plant (WWTP), which demonstrated the feasibility of the developed method. Compared with enzymatic hydrolysis, the acid-catalyzed solvolysis method developed here to deconjugate estrogen conjugates is cost effective and time-saving, giving it a greater potential for use with environmental samples.
本文采用三种1M盐酸（HCl）的甲醇溶液研究了天然雌激素缀合物的去共轭反应。即使在低温下，雌激素硫酸盐也能很容易地去共轭，而雌激素葡萄糖醛酸苷的去共轭条件需要更高的温度和更长的时间。对于含8%水的1M HCl甲醇溶液，在80℃下反应360分钟，三种研究的雌激素葡萄糖醛酸苷的去共轭效率低于59.4%，而对于无水HCl甲醇，在80℃下反应210分钟，相应的去共轭效率高于80.6%，这表明1M HCl甲醇溶液中的微量水会延缓雌激素葡萄糖醛酸苷的去共轭速率。另一方面，加入乙酸乙酯后它们相应的去共轭速率增加，在80℃下反应120分钟时相应的去共轭效率高于86.7%。由于水是一种高极性溶液，而乙酸乙酯的极性低于甲醇，这可能表明低极性物质有利于反应，而高极性溶液会抑制反应。所有反应均为拟一级反应，温度升高会加快反应速率。最后，建立了一种气相色谱 - 质谱联用（GC - MS）方法，用于同时分析酸性催化溶剂解作用下废水中的游离雌激素和雌激素缀合物，通过向一个城市污水处理厂（WWTP）的进水和出水中添加标准目标化学物质，获得了令人满意的回收率，这证明了所开发方法的可行性。与酶水解相比，本文开发的用于使雌激素缀合物去共轭的酸催化溶剂解方法具有成本效益且节省时间，在环境样品分析中具有更大的应用潜力。
