甲砜霉素与氟苯尼考的辐照降解机理研究  

Degradation Mechanism Study of Thiamphenicol and Florfenicol by Radiolysis

作　　者：周佳欣[1] 吴明红[1] 姚思德[2] 

机构地区：[1]上海大学射线应用研究所,上海200444 [2]中国科学院上海应用物理研究所,上海201800

出　　处：《化学学报》2011年第20期2479-2485,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.40973073;40830744);上海重点学科项目(No.S30109);"十一五"国家科技支撑计划重点项目(Nos.2008BAC32B03;2009BAA24B04)资助项目

摘　　要：对甲砜霉素(THA)和氟苯尼考(FLO)的辐照降解进行了瞬态产物和稳态产物的分析.利用脉冲辐解技术研究了THA/FLO水溶液在各种条件下与·OH,e-aq和·H的反应机理,研究表明:THA/FLO与·OH反应途径与pH有关:中性条件下主要发生苯环上的加成反应,其速率常数分别为为1.09×108 L·mol-1·s-1(THA)和3.14×108 L·mol-1·s-1(FLO);碱性条件下,则断裂产物在·OH催化下的去OH-反应.e-aq的进攻导致THA/FLO脱Cl-和F-,该反应中性条件比碱性条件更易进行.THA/FLO与·H发生加成反应,生成较稳定的氢加成产物,反应速率分别为3.52×107 L·mol-1·s-1(THA)和2.43×108 L·mol-1·s-1(FLO).利用GC/MS对电子束辐照的稳态产物分析,得出自由基反应生成的小分子碎片.结合瞬态反应过程,得出THA/FLO降解途径.Steady-state and pulse radiolysis experiments have been performed to gain insight into the mechanism of Thiamphenicol（THA） and Florfenicol（FLO） degradation in aqueous solutions.Redox reac-tions of aqueous THA and FLO solutions with ·OH,e-aq,and ·H were studied by using pulse radiolysis techniques.The results indicated that the reaction pathway between THA/FLO and ·OH was dominated by the initial solution pH value.In neutral condition,the addition reaction happened between ·OH and benzene ring.The rate constants for the reactions of ·OH with THA and FLO were found to be 1.09×108 L·mol-1· s-1 and 3.14×108 L·mol-1·s-1 respectively.But in alkaline condition,the organic bond OH-was removed by ·OH.The dechlorination of THA and FLO was caused by e-aq attacking.The ·H added on the benzene ring forming relative stable products,and the rate constants for the reactions of ·OH with THA and FLO were 3.52×107 L·mol-1·s-1 and 2.43×108 L·mol-1·s-1,respectively.The reaction in alkaline solution was also discussed.The radiolysis degradation by-products were identified by GC/MS analysis and their degra-dation pathway were also conducted.

关 键 词：甲砜霉素 氟苯尼考 脉冲辐解 降解机理 

分 类 号：X13[环境科学与工程—环境科学]