冰中9-羟基芴的光化学降解  

Photochemical degradation of 9-hydroxyfluorene in ices

作　　者：葛林科[1,2] 任红蕾[1,2,2] 霍城[1,2] 那广水[1,2] 王莹[1,2] 李凯[1,2,3] 张蓬[1,2] 姜华[2] 

机构地区：[1]国家海洋局近岸海域生态环境重点实验室 [2]国家海洋环境监测中心,大连116023 [3]大连海洋大学海洋科技与环境学院,大连116023

出　　处：《中国科学：化学》2015年第6期655-661,共7页SCIENTIA SINICA Chimica

基　　金：极地科学战略基金(20120320);国家自然科学基金(21007013,41106079,21207025);南北极环境综合考察与评估专项(CHINARE2012-02-01);海洋局青年海洋科学基金(2012501);近岸海域生态环境重点实验室开放基金(201007)资助

摘　　要：羟基多环芳烃(OH-PAHs)是PAHs羟基化的一类新型污染物,广泛存在于水、大气等环境介质中,并潜在存在于极地冰雪中,研究其环境行为和毒理效应具有重要意义.以9-羟基芴(9-OHFL)为模型化合物,考察了光照(λ>290 nm)作用下冰中9-OHFL的光降解动力学、影响因素、转化产物及光修饰毒性.9-OHFL的光降解遵循准一级反应动力学,纯水冰中速率常数为0.0092 min-1,表观光解量子产率为0.022.外推至实际环境,南极长城站附近夏天中午冰雪表面9-OHFL的半减期为54 h.与纯水冰中相比,海水冰、淡水冰中光降解较快,这归因于水中主要溶解性物质的影响,Cl-,NO3-,Fe(III)及低浓度腐殖酸均可促进9-OHFL的光降解.通过GC-MS/MS分析,纯水冰中9-OHFL光化学转化生成了5种主要产物,涉及的转化路径为脱氢氧化、异构化和苯环羟基化.毒性实验表明,9-OHFL对发光菌(Vibrio fischeri)表现为光修饰毒性.本研究所揭示的9-OHFL光降解规律和光化学转化风险对于极地冰雪环境中OH-PAHs类污染物的归趋和风险评价具有重要意义.Hydroxyl polycyclic aromatic hydrocarbons （OH-PAHs） are derived from hydroxylated PAHs as new contaminants. They are ubiquitous in the aqueous and atmospheric environment and may exist in the arctic snow and ice, so it is of great significance to investigate their environmental transformation and toxicity. In this study, simulated-solar （2〉290 nm） photodegradation kinetics, influencing factors, products and photoinduced toxicity of 9-hydroxyfluorene （9-OHFL, a representative OH-PAHs） in ices were investigated. The photodegradation follows the pseudo-first-order kinetics. It photodegrades with a rate constant of 0.0092 min-1 and a quantum yield of 0.59 in pure water. Extrapolation of these data to the real environment is expected to provide a half-life of 54 h in surface snow and ice at mid-summer noon of China Greatwall Station, the Antarctic. The 9-OHFL photodegrades faster in freshwater ice and seawater ice than in pure water ice, which is attributed to the effects of main aqueous dissolved matter （e.g., CI-, NO3-, Fe（III） and hnmic acids） that accelerate the photodegradation. Based on GC-MS/MS, 5 main intermediates are generated from the 9-OHFL photodegradation in pure water ice, which suggests that the OH-PAH undergo oxidization, isomerization and hydroxylation when photolyzed. A toxicity test using Vibrio fischeri revealed the photomodified toxicity of 9-OHFL. These results are of importance toward the goal of assessing the persistence and risk of OH-PAHs in the arctic snow and ice.

关 键 词：9-羟基芴 光降解 动力学 转化产物 光修饰毒性 

分 类 号：O644.1[理学—物理化学] O625.153[理学—化学]