本文运用脉冲辐解探究了不同自由基与药物氟西汀(FLX)之间的反应.羟基自由基(·OH)与FLX反应生成苯环上的羟基加成物,而硫酸根阴离子自由基(SO4·-)则通过单电子氧化FLX生成苯阳离子自由基,该中间产物再进一步与水反应生成苯环上的羟基加成物.本研究测定了三种自由基·OH,水合电子(eaq-)以及SO4·-与FLX反应的反应速率常数分别为:7.8×109,2.3×109和1.1 x 109 mol·L-1·s-1.本文还运用电子束辐照技术探究了不同辐照条件下的FLX降解效果,结合HPLC和紫外可见光谱仪进行分析.在N2O和空气饱和的两种条件下,FLX溶液经1.5 kGy辐照后降解效率均达到90％以上,而N2饱和条件下,加入0.1 mol·L-1的叔丁醇的FLX溶液经1.5 kGy辐照后仅有43％分解.此外,酸性和中性条件下FLX的降解效率均大于碱性条件下的.结果阐明了饱和空气的FLX溶液在中性条件下的降解效果最佳,且·OH诱导的反应比SO4·-更有利于FLX的分解.本研究期望对于进一步探究FLX的降解反应提供有益的帮助.%The reactions of the pharmaceutical fluoxetine (FLX) with different radicals were investigated by pulse radiolysis.The reaction of hydroxyl radical (· OH) with FLX formed hydroxylated adduct of the aromatic ring,while oxidation of FLX by sulfate radical anion (SO4·-) formed benzene radical cation that further reacted with H2O to yield the · OH adduct.The determined rate constants of · OH,hydrated electrons (eaq-),and SO;with FLX were 7.8 × 109,2.3 x 109,and 1.1 × 109 mol·L-1 ·s-1,respectively.In the steady-state radiolysis study,the degradation of FLX in different radiolytic conditions by electron beam irradiation was detected by HPLC and UV-Vis spectra techniques.It was found that FLX concentration decreased by more than 90％ in both N2O and air-saturated solutions after 1.5 kGy irradiation.In contrast,only 43％ of FLX was decomposed in N2-saturated solution containing 0.1 mol· L-1 tea-butanol.The degradation rates of FLX in acidic and neutral solutions were higher than those in alkaline solutions.Our results showed that the degradation of FLX is optimal in air-saturated neutral solution,and · OH-induced degradation is more efficient than SO4·-oxidation of FLX.The obtained kinetic data and optimal conditions give some hints to understand the degradation of FLX.
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