【作者】 李瑞波；

【导师】 林金明；

【作者基本信息】 北京化工大学 ， 化学， 2012， 博士

【摘要】 多环芳烃广泛存在于水，大气，土壤等环境介质中。由于其致畸，致癌，致突变性，所以越来越受到人们的关注。检测和控制环境中的多环芳烃具有重要的意义。化学发光是一种灵敏度高，仪器简单，操作简便的分析方法。本研究建立了亚硫酸氢钠-过氧化氢化学发光体系检测含氧多环芳烃的分析方法。并且对反应机理进行了研究。主要内容如下：1、在这项工作中，我们观察到亚硫酸氢钠和过氧化氢反应产生超微弱的化学发光现象。羟基自由基和亚硫酸根自由基是这个反应中产生的两个重要的中间体。自由基抑制剂硫脲、卤素离子、NBT、DMPO对化学发光强烈的抑制作用，表明了羟基自由基和亚硫酸根自由基的存在。在NaHSO3-H2O2化学发光体系中，SO*2和1O2是发光体。通过DABCO和NaN3的抑制作用可以证明1O2的存在。除此之外，我们还通过ESR谱检测到了.OH和1O2的存在。醇溶剂，特别是正丁醇对化学发光强度有增强作用。醇溶剂的增强作用主要是由于醇在水溶剂中形成了类似于表面活性剂胶束的溶剂笼，这种溶剂笼能保护化学发光中间体和自由基不会受到水的猝灭作用。体系的最大发光波长在490nm左右，这说明了1O2的存在。2、NaHSO3-H2O2反应产生超微弱的化学发光，发光体是SO*2。加入OH-PAHs之后，SO₂^-将能量转移给OH-PAHs，从而增强化学发光。根据这个原理，我们建立了检测OH-PAHs的分析方法。并且将这个方法成功的应用于检测大气颗粒物中的1-羟基芘。该方法的检测线性范围是0.5-50pmol （R2=0.9983）,检测限是100fmol。该方法成功应用于检测日本金泽市大气颗粒物中的1-OHP的浓度。2010年8月金泽市大气颗粒物中1-OHP的平均浓度大约为2.0pg/m³。3、7,10-BaPQ自身没有荧光，但是，当加入到NaHSO₃-H₂O₂化学发光体系中，化学发光得到明显的增强。化学发光动力学曲线研究发现NaHSO₃-H₂O₂大约0.1秒就达到最大发光值，2秒左右就降至基线。7,10-BaPQ的存在并没有改变NaHSO3-H2O2化学发光速率。通过自由基抑制剂的抑制作用、ESR谱图、HPLC等手段，可以推测出.OH，.O₂^-和.SO₃^-自由基的存在。.O-2能氧化7,10-BaPQ生成激发态的半醌，从而产生化学发光现象。NaHSO_3-7,10-BaPQ-H₂O₂化学发光体系的大发光波长在440nm左右，可能是激发态的半醌的发光。另外，ESR图也检测到了半醌自由基的存在。根据这个原理，建立了一种高灵敏度得检测大气颗粒物中7,10-BaPQ的分析方法，线性范围是50fmol-20pmol （R2=0.9995）,检测限是30fmol。2010年12月日本金泽市和轮岛市大气颗粒物中的7,10-BaPQ的平均浓度大约为2.0和1.6pg/m3.更多还原

【Abstract】 Polycyclic aromatic hydrocarbons （PAHs）are distributed in thewater, airborne particulates and soil samples. More and more attentionshave been paid on PAHs. It is very important to monitor and controlvariations of PAHs in environment. Chemiluminescence is one kind ofvery sensitive method. The instrument is simple and easy to be operated.In this research, we established a very sensitive chemiluminescencemethod to determine oxygenated polycyclic aromatic hydrocarbons inairborne particulates. In addition, we study the mechanism ofNaHSO₃-H₂O₂. The main works of this research are shown as follow:1. In this work, a chemiluminescence （CL） reaction between hydrogenperoxide （H₂O₂） and sodium hydrosulfite （NaHSO3） was developed.Hydroxyl radical （.OH）, and sulfite radical （.SO₃^-） were the mainintermediates generated in NaHSO3-H2O2CL system. Inhibition effects of radical scavengers such as thiourea, chloride ion, nitro blue tetrazoliumchloride （NBT）, and5,5-dimethyl-1-pyrroline N-oxide （DMPO）indicated the existence of these two radicals. Singlet oxygen （1O2） andexcited sulfur dioxide （SO₂*） were emitting species involved inNaHSO3-H2O2CL system.1O2were confirmed by1,4-diazobicyclo [2,2,2] octane （DABCO） and sodium azide （NaN3）, which were specific1O2scavengers. In addtion, electron spin resonance （ESR） spectra clearlyshow the existence of1O.2andOH. Alcoholic solvent, especiallyn-butanol, enhanced the ultra-weak CL emission more than forty times.The enhancing effect of alcoholic solvent on NaHSO3-H2O2CL systemwas ascribed to the formation of solvent cage, which can accelerate thereaction rate and protect the emitting species from quenching by water.CL emission of NaHSO3-n-butanol-H₂O₂system was measured by cut-offfilters. The maximum wave length was located around490nm, whichbelongs to¹O₂. The wide peak from400nm to600nm is thecharacteristic peak of SO₂^-.2. In this research, a highly sensitive chemiluminescence methodbased on a sodium hydrosulfite （NaHSO3）-hydrogen peroxide （H2O2）reaction for the determination of OH-PAHs was developed. The proposedmethod was applied to determine the concentrations of1-OHP in airborneparticulates. The response of this system was linear in the range from0.5to50pmol （R²=0.9983）. The limit of detection for1-OHP was100fmol （S/N=3）.1-OHP in airborne particulates was well separated frominterfering compounds using an ODS column with75%methanol as themobile phase in isocratic mode. The proposed method was successfullyused to determine the1-OHP in airborne particulates collected inKanazawa, Japan. The average concentration of1-OHP in the atmospherewas2.0pg/m³.3. An ultra-weak chemiluminescence （CL） was observed whensodium hydrosulfite （NaHSO3） reacts with hydrogen peroxide （H₂O₂）,and enhanced70times by adding10pmol benzo[a]pyrene-7,10-quinone（7,10-BaPQ）. The CL reaction is fast and it reached maximum intensity in0.1s, and then decayed to base line in3s. Mechanism of NaHSO3-7,10-BaPQ-H₂O₂system were investigated by CL spectrum, radicalscavengers and electron spin resonance （ESR）. Hydroxyl radical （.OH）,super oxide anion radical （.O₂^-）, and sulfite radical （.SO₃） were generatedin the NaHSO3-7,10-BaPQ-H₂O₂system. Reduction of7,10-BaPQby.O-2radical gave excited semiquinone, which showed strong CLemission when decayed to its ground state. Maximum CL emissionwavelength was located at440nm, which may belong to the excitedsemiquinone. This CL system was developed as post column detection ofhigh performance liquid chromatography for the determination of7,10-BaPQ. Linearity ranged from50fmol to20pmol （R2=0.9995） withlimit of detection of30fmol （S/N=3）. The proposed method was used to determine7,10-BaPQ in airborne particulates. Average atmosphericconcentrations of7,10-BaPQ in Kanazawa in December2010andWajima in October2007were2.0and1.6pg/m3, respectively.更多还原