16种多环芳烃的结构式教学文案

16种多环芳烃结构-回复题目：16种多环芳烃结构的特征及其对环境的影响导言：多环芳烃（Polycyclic Aromatic Hydrocarbons，简称PAHs）是一类由两个以上的苯环通过共边共轭连接而成的有机物。

它们广泛存在于自然界和工业化学品中。

本文将详细探讨16种多环芳烃结构的特征及其对环境的影响。

第一节：多环芳烃结构的特征1.2环芳烃：衍生物：字母[a]对位二苯并蒽、字母[b]对位二苯并蒽、蒽、见血解剖达决战、萘、菲特征：具有两个苯环，对位相连，可通过横向扩展形成其他环芳烃。

2.3环芳烃：衍生物：呋喃、芴、十字花苷、哌啶、莰特征：具有两个苯环和一个非对位连接的环，形态多样且具有不同的生物活性。

3.4环芳烃：衍生物：麦基威廉斯氏硬脂煤催化剂、花菜花城堡、黄莺浓缩、咖啡、蘑菇、玉米丝、鸡尾酒、艾滋病新鲜馅饼、巧克力蛋糕特征：具有四个苯环，形状各异，对环境影响较大。

4.5环芳烃：衍生物：苯并螺并苯并邻苯并传帮带啉、差不多隆老批螺乙烯、女珍珠、柳宗元、人丁大帝橙酸、12位旅行家特征：具有五个苯环，多具有毒性，对环境和生物造成较大危害。

第二节：多环芳烃的环境污染1. 来源：a. 自然源：包括火山喷发、森林火灾和化石燃料的燃烧，如煤、石油和天然气的燃烧。

b. 人工源：工业废水、大气颗粒物、污染土壤。

2. 影响环境：a. 水环境污染：多环芳烃污染会导致水生生物的死亡、生殖系统受损、癌症发生率上升等。

b. 大气环境污染：多环芳烃是空气中的重要污染物，通过空气传播进入人体呼吸系统，对人体健康有害。

c. 土壤环境污染：多环芳烃在土壤中的滞留时间长，对土壤微生物和植物生长产生负面影响。

第三节：多环芳烃的治理和防控1. 监测与评估：a. 多环芳烃的测量技术研发与完善；b. 环境中多环芳烃的监测与评估；c. 风险评估和环境质量标准的制定。

2. 污染物治理：a. 政策法规的制定和落实；b. 工业污染的控制和减排；c. 生态修复和环境整治。

16种多环芳烃的结构式多环芳烃 (Polycyclic Aromatic Hydrocarbons, PAHs) 是由两个或两个以上的芳香环连接而成的有机化合物。

这些化合物通常由碳和氢原子组成，具有一定的环状结构和共轭体系，因此在化学性质和生物学活性上具有独特的特点。

在环境中，PAHs是一类普遍存在的化合物，它们可以来自燃烧、化石燃料的使用、工业排放、车辆尾气和污水处理厂等源头。

下面将介绍其中的16种典型多环芳烃及其结构式。

1. 苯 (Benzene, C6H6)苯是最简单的多环芳烃，由一个六元芳香环组成。

它是一种无色液体，具有刺激性气味。

苯具有很高的环境稳定性和易挥发性，且对人体有毒性。

2. 萘 (Naphthalene, C10H8)萘由两个共轭苯环组成，是一种无色固体，有特殊的芳香气味。

它主要用作防蛀剂和染料的前体物质，也广泛应用于塑料和橡胶等工业。

3. 菲 (Phenanthrene, C14H10)菲是一种具有三个对位芳香环的多环芳烃。

它是一种固体物质，在环境中存在且具有显著的毒性。

菲也是石油污染的指示物质之一4. 蒽 (Anthracene, C14H10)蒽是由三个对位苯环连接而成的多环芳烃，是一种白色结晶固体。

它广泛用于染料、橡胶和塑料工业。

5. 蒽醌 (Anthraquinone, C14H8O2)蒽醌是蒽的衍生物，具有两个酮基（O=C）的结构。

它是一种重要的有机合成原料，广泛应用于染料、药物和化妆品等领域。

6. 芘 (Pyrene, C16H10)芘由四个共轭苯环连接而成，是一种固体物质。

它具有很高的环境稳定性和毒性，是一种常见的环境污染物。

7. 苊 (Chrysene, C18H12)苊是一种具有四个对位芳香环的多环芳烃，是无色结晶固体。

它是一种常见的环境污染物，具有较高的生物累积性。

8. 梦菲 (Fluoranthene, C16H10)梦菲由四个共轭芳香环连接而成，是一种白色固体。

Determination of16polycyclic aromatic hydrocarbons in seawater using molecularly imprinted solid-phase extraction coupled with gas chromatography-mass spectrometryXingliang Song a,b,1,Jinhua Li b,1,Shoufang Xu b,d,Rongjian Ying a,Jiping Ma c,Chunyang Liao b, Dongyan Liu b,Junbao Yu b,Lingxin Chen b,na School of Chemistry&Chemical Engineering,Linyi University,Linyi276005,Chinab Key Laboratory of Coastal Zone Environmental Processes,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Chunhui Road17,Laishan District,Yantai264003,Chinac Key Laboratory of Environmental Engineering of Shandong Province,Institute of Environment&Municipal Engineering,Qingdao Technological University,Qingdao266033,Chinad Graduate University of Chinese Academy of Sciences,Beijing100049,Chinaa r t i c l e i n f oArticle history:Received8April2012Accepted30April2012Available online21May2012Keywords:Polycyclic aromatic hydrocarbonsMolecularly imprinted polymersSolid-phase extractionSeawater samplesSol–gel processGas chromatography-mass spectrometrya b s t r a c tA method of solid-phase extraction(SPE)using molecularly imprinted polymers(MIPs)as adsorbentcoupled with gas chromatography-mass spectrometry(GC–MS)was developed for the determination of16types of polycyclic aromatic hydrocarbons(PAHs)in seawater samples.The MIPs were preparedthrough non-covalent polymerization by using the16PAHs mixture as a template based on sol–gelsurface pared with the non-imprinted polymers(NIPs),the MIPs exhibited excellentaffinity towards16PAHs with binding capacity of111.0–195.0m g gÀ1,and imprinting factor of1.50–3.12.The significant binding specificity towards PAHs even in the presence of environmentalparameters such as dissolved organic matter and various metal ions,suggested that this newimprinting material was capable of removing93.2%PAHs in natural seawater.High sensitivity wasattained,with the low limits of detection for16PAHs in natural seawater ranging from5.2–12.6ng LÀ1.The application of MIPs with high affinity and excellent stereo-selectivity toward PAHs in SPE mightoffer a more attractive alternative to conventional sorbents for extraction and abatement of PAH-contaminated seawater.&2012Elsevier B.V.All rights reserved.1.IntroductionPolycyclic aromatic hydrocarbons(PAHs),among the group ofpersistent organic pollutants(POPs),have received great concerns inrecent years because of their high lipophilicity,carcinogenicity andubiquitousness in the environment[1–5].The prolonged accumula-tion of PAHs has posed severe threats to the environment andhuman health.So,identification and measurement of PAHs hasmicroextraction(LPME)[9],solid-phase extraction(SPE)[10,11],stirring bar sorptive extraction(SBSE)[12],and solid-phase micro-extraction(SPME)[13].SPE,due to its advantages[10,14],has beenwidely employed for concentration of PAHs in water samples[10,11,15,16].Meanwhile,it is well known that low selectivity andlow adsorption capacity are existing main problems associated withtraditional sorbents of SPE.A new type of high efficiency sorbent,molecularly imprinted polymers(MIPs),owing to high sample loadcapacity,high selectivity,high mechanical and thermal stability,lowcost and easy preparation,have been increasingly used(e.g.SPEsorbent)for preconcentration and high efficient separation ofvarious trace analytes in diverse matrices[17–21],based on theirunique imprinting and recognition properties.On the other hand,it is well known that PAHs are a class ofhighly lipophilic compounds without any pronounced functionalgroups in their molecules,and the non-covalent interactions likehydrogen bond,dipolar and/or ionic interactions between PAHsand functional monomer cannot be formed.So,it seems mostdifficult to imprint PAHs since the only available interactions inthe imprinting and recognition process are the hydrophobicContents lists available at SciVerse ScienceDirectjournal homepage:/locate/talantaTalanta0039-9140/$-see front matter&2012Elsevier B.V.All rights reserved./10.1016/j.talanta.2012.04.065n Corresponding author.Tel./fax:þ865352109130.E-mail address:lxchen@(L.Chen).1Equally contributed to this work.Talanta99(2012)75–82interaction,steric cavity,and p–p interaction,which are one or two orders of magnitude weaker than the electrostatic forces[22]. To the best of our knowledge,only several publications have reported PAHs determination based on MIPs by using PAHs as template/analyte.For instances,Benzo[a]pyrene(BaP)was used as a template molecule to synthesize six kinds of MIPs using different functional monomers and cross-linkers for enrichment and separation of BaP from water and coffee samples[23],as well as,pyrene was used as a template molecule to prepare MIPs with molecular recognition properties towards many PAHs[24].The double molecular imprinting for measurements of PAHs in water was performed with quartz crystal microbalance[25].Besides, the double template imprinting was employed for dispersive solid-phase microextraction and attained satisfactory cleanup and enrichment efficiency for three PAHs in seawater[26].The multi-molecular imprinting technique was proposed that the MIP-particles were prepared by using six PAHs mix as a template, and successfully applied for selective adsorption of PAHs[27,28]. Furthermore,the MIPs-SPE withfive-PAH mix as template was employed,and thereby highly sensitive determination of PAHs in ambient air dust was attained by GC–MS[29].However, most of the fabrication processes used above in molecularly imprinting is still complex,removing the template is difficult, and the kinetics of the sorption/desorption process is often unfavorable[18,30,31].To solve these problems,surface imprinting[30,31]has been used herein,and an ultrathin polymer coating on a solid support substrate through the surface imprinting approach can conduce to easy removal of template as well as improved mass transfer of PAHs.A multi-molecular imprinting approach for PAHs was demonstrated,based on a surface imprinting sol–gel process. The MIPs sorbents were synthesized in acetonitrile by using16 PAHs mix standards as a template,phenyltrimethoxysilane as the functional monomer,and tetraethoxysilane as the cross-linker. Numerous binding cavities were produced in the polymer matrix because of the advantages of PAHs with condensed benzene rings and non-reactivity between PAHs molecules.Binding selectivity and matrix effects of the MIPs were investigated in detail.The molecularly imprinted SPE(MISPE)was successfully applied to enrich16PAHs from spiked samples such like artificial and natural seawater.2.Experimental2.1.Materials and instrumentationSixteen standard PAHs,i.e.,naphthalene(Nap),acenaphthy-lene(Acy),acenaphthene(Ace),fluorene(Fl),phenanthrene(Phe), anthracene(Ant),fluoranthene(Flu),pyrene(Py),benz[a]anthra-cene(BaA),chrysene(Chr),benzo(b)fluoranthene(BbF),benzo[k]-fluoranthene(BkF),benzo[a]pyrene(BaP),indeno[1,2,3–cd]pyrene(IPy),dibenz[a,h]anthracene(DahA)and benzo[ghi]-perylene(BghiP),nominated as priority pollutants by United States Environmental Protection Agency(EPA),dissolved in methylene dichloride,were purchased from Supelco(Bellefonte, PA,USA),individual at2000mg LÀ1.The related information such as structures and physicochemical properties of the16PAHs can be found in our previous work[9].Stock solutions at the concentration of10mg LÀ1were prepared in acetonitrile,and working solutions were prepared daily by appropriate dilution of the stock solutions with seawater before use.Silica gel(400–600 mesh,Qingdao Ocean Chemical Co.,Qingdao,China)was used as the carrier of MIPs.Phenyltrimethoxysilane(PTMS)and tetra-ethoxysilane(TEOS),obtained from Tianjin Chemical reagent Co. Ltd(Tianjin,China),were used as functional monomer and cross-linker,respectively.Acetonitrile(HPLC grade,Tianjin Chemical, Tianjin,China)was used as solvent,and acetic acid(analytical grade,Ji’nan Chemical,Ji’nan,China)was used as polymerization initiator.Acetone(analytical grade,Laiyang Xinglin Chemical Co., Ltd,Laiyang,China),methanol(HPLC grade,Ji’nan Friend Chemi-cal Co.,Ltd,Ji’nan,China)and dichloromethane(DCM)were used for elution of the template.Other affiliated chemicals and materi-als were all obtained from Sinopharm Chemical Reagent Co.Ltd. (Shanghai,China)and local suppliers(Linyi,China).All other solvents and reagents were of analytical grade and used without further purification.Doubly deionized water(DDW)obtained by a Milli-Q Ultrapure water system(Shanghai Yarong Instrument Co., Ltd,Shanghai,China)was used throughout the experiments.GC/MS QP2010coupled with a split/splitless injector system and a quadrupole mass spectrometer(Shimadzu,Japan)was used for separation and determination of PAHs.High-speed Centrifuge (G16-WS,Hunan Xiangyi Laboratory Instrument Development Co.,Ltd,China)was employed for centrifugation.Super Digital Display Thermostatic Bath(SYC-15,Nanjing,China)was used for heating.Vacuum Drying Chamber(DZF-6051,Nanjing,China)was used for drying of MIPs.Solid Phase Extraction Vacuum Manifolds (Mate-24,Shanghai Quandao Technical Company,Shanghai, China)was employed for SPE process.Digital Full-Temperature Oscillator(HZQ-2,Jiangsu Jintan Medical Instrument Factory, China)was used for oscillation.2.2.Preparation of molecularly imprinted sol–gel adsorbentThe procedure for activating the silica gel(400–600mesh)was referred to that reported in reference[32]with necessary mod-ification.The MIPs sorbent was synthesized in a250mL glass vessel using25mL acetonitrile as a solvent.500mg mLÀ116 standard PAHs solution(1mL)and5.0mL PTMS were dissolved in acetonitrile,then the mixture was incubated for30min at51C in a water bath.Into the activated silica gel(1.0g),TEOS(4mL) and acetic acid(2.00mL)were added and stirred for another 20min.The acetic acid was used as a polymerization initiator(2.0mL),while PTMS was used as a functional monomer,TEOS asa cross-linking agent and the16standard PAHs as template molecules.The mixture was incubated while stirring at400rpm for24h at601C in a water bath.The resulting particles were collected on a glassfilter,washed extensively with50mL of methanol overnight continuously,washed with15mL of metha-nol for1h,and dried at1001C for12h.Cleaned beads were extracted by DCM in a soxhlet extractor,and this procedure was repeated until the template molecules could not be detected in the washed solvent by GC–MS.The corresponding non-imprinted polymers(NIPs)were prepared in parallel in the absence of template and treated in the same manner.2.3.Characterization of the polymersThe prepared polymers were characterized by scanning elec-tron microscopy(SEM),nitrogen adsorption experiments and Brunauer-Emmett-Teller(BET)analysis,Fourier transform infra-red spectroscopy(FT-IR)and gas chromatography-mass spectro-metry(GC–MS).SEM images were recorded using a scanning electron micro-scope(SEM,Hitachi S-4800,operating at an accelerating voltage of5kV and a magnification200000Â).All samples were sputter-coated with gold before SEM analysis.Nitrogen adsorption-desorption results were recorded using AUTOSORB1(Quantachrome Instruments,Germany).The BET method was used to determine the specific surface area,perform-ing for N2relative vapor pressure of0.05–0.3at77K.The samplesX.Song et al./Talanta99(2012)75–82 76were degassed in a vacuum at3001C prior to adsorption measurements.FT-IR spectroscopic measurements were performed on model Avatar370FT-IR Spectrometer(Thermo Nicolet Corporation,USA) with KBr pellet method.The wave numbers of FT-IR measurement range were controlled from500to4000cmÀ1,and collected at one data point per2cmÀ1with sample scanning for32times.GC–MS conditions employed for PAHs separation and deter-mination were as follows:a quadrupole mass spectrometer was operated in the electron ionization mode at70eV and mass spectra were acquired with a selected ion monitoring(SIM)mode. Separation was carried out on a Rtx-5MS capillary column (30mÂ0.25mm)with a0.25m m stationaryfilm thickness,95% methyl–5%phenyl copolymer column(Shimadzu,Tokyo,Japan). The oven temperature was programmed as follows:initial701C (held for2min),increased to901C(held for4min),afterwards increased to2901C at a rate of101C minÀ1,and eventually held for20min.The total time for one GC run was44min.The injector temperature was set at2501C,and the injection was performed in a splitless mode for1min.Helium(purity99.999%)was employed as carrier gas at aflow rate of1.0mL minÀ1.2.4.Adsorption capacity of the polymersTo evaluate the adsorption capacity of the obtained polymers, a dynamic adsorption test and a static adsorption test for PAHs were carried out in the artificial seawater and natural seawater samples,respectively.By monitoring the temporal amount of PAHs in the solutions,the procedures of the dynamic adsorption test were performed as follows:50mg of MIPs were dissolved in 10mL of seawater spiked with2m g LÀ1individual PAH standards, and then the mixture was continuously oscillated in a thermo-statically controlled water bath at room temperature for1–24h; the polymers were removed centrifugally,and then the5mL of supernatant was extracted by using dispersive liquid-liquid microextraction(DLLME)procedure[9,33,34]into a10mL glass-centrifuge tube;and then the analytes were located in the bottom of the tube,1m L of which was sampled for GC–MS analysis.For each adsorbent,these experiments were repeated at least triplicates.Meanwhile,the static adsorption test was carried out by allowing a weighted amount of MIPs to reach the equilibrium (the adsorption equilibrium would be obtained within20h)with PAHs standard solution of known concentration from 1.0to 10.0m g LÀ1.The same procedure was used to test the adsorption amounts of NIPs.Equilibrium amounts of PAHs bound to the MIPs(B)were calculated by the following equation:B¼ðF0ÀF tÞVwhere,F0and F t are the concentrations(m g LÀ1)of PAHs mea-sured at initial and after interval time for equilibrium,respec-tively;V and W are the volumes of the PAHs solution and the weight of the dried polymers used for the binding experiments, respectively.2.5.Molecularly imprinted solid-phase extraction(MISPE) procedureThe polymers of0.15g were packed into an empty SPE cartridge of3.0mL(purchased from Agilent Technologies,USA) between two PTFE frits with10m m in porosity size.Prior to loading the sample,the cartridge was washed with a mixture of DCM/acetic acid(9:1,v/v)until PAHs could not be detected by GC–MS in thefiltrate,and then5mL artificial seawater was used for activation.A30.0mL seawater solution spiked with a known concentration of PAHs was percolated through the MIPs or NIPs cartridge.The cartridge was washed with2.0mL methanol/H2O (1:9,v/v).Then the analytes were eluted from the cartridge by using 2.0mL of DCM/acetic acid(9:1,v/v)forfive times.This fraction was then collected and concentrated up to0.5mL under an ice-water bath in nitrogen stream.One microliter(1m L) samples were analyzed by GC–MS to quantify the recovered PAHs.3.Results and discussion3.1.Preparation and characterization of MIPs for PAHsNon-covalent molecular imprinting method was adopted to prepare MIPs for PAHs.Theoretically,the imprinting effect of MIPs towards its template mainly depends on the interaction between the template and the functional monomer.PAHs are poly-electronegative molecules with condensed benzene rings, and have no distinct functional groups.So,PTMS as functional monomer was employed for the imprinting and recognition process,possibly owing to the hydrophobic interaction and p–p interaction.The weakly polar acetonitrile was chosen as porogen because strongly polar solvents could counteract the formation of affinity bonds for templates,and acetic acid was chosen as the activator during the synthesis of molecularly imprinted sol–gel [35].Thus,the imprinting process of PAHs regularly encoded the PAH shape of-SiO–SiO–SiO-conjoined to a functional phenyl group,and the specific cavity was formed after the imprinted molecule was eluted.Fig.1shows the FT-IR spectra of activated silica gel(curve a), non-imprinted silica gel(curve b)and imprinted silica gel(curve c).As seen in Fig.1a,the strong peaks at469,800and1102cmÀ1 can be attributed to the stretching vibration of Si–O–Si,indicating the formation of silica gel;the broad peaks at3439and 1637cmÀ1might represent the stretching vibration oftheFig.1.SEM images of(a)activated silica gel,(b)non-imprinted silica gel and (c)imprinted silica gel.X.Song et al./Talanta99(2012)75–8277associating hydroxyl and the bending vibration of hydroxyl of the silica gel,respectively[36].As illustrated in Fig.1b and c,the peaks at2927and2870cmÀ1can be assigned to the stretching vibration of C–H of methyl;the weak absorbance peak nearby 1636cmÀ1showed the appearance of skeleton vibration absorp-tion of benzene-ring from the non-imprinted and imprinted silica gel.These observations suggested that PTMS was successfully grafted to the surface of silica gel and the thinner silicafilms were fabricated in MIPs and NIPs,respectively,according to the weak signals judgment.Additionally,the hydroxyl bending vibration peaks near3446cmÀ1(Fig.1c)in MIPs showed obvious blue shift relative to that of activated silica gel at3439cmÀ1(Fig.1a), representing the obvious interactions between hydroxyl with strong polarity and benzene rings with weak polarity.The results of FT-IR confirmed that the non-covalent imprintedfilm was successfully introduced onto the surface of silica gel based on sol–gel process.Fig.2shows the SEM images of activated silica gel(a),non-imprinted silica gel(b)and imprinted silica gel(c).As displayed, the MIPs contained pores embedded in the network while NIPs had a relatively smooth surface.Moreover,by BET analysis,the specific surface area of MIPs was attained of289.1m2gÀ1,higher than that of NIPs(270.2m2gÀ1)and activated silica gel (265.8m2gÀ1).So,the coating of imprintedfilm on the activated silica gel increased the specific surface area by using PAHs to create the polymeric microstructure,and thereby could accelerate mass transfer and improve adsorption capacity.3.2.Evaluation of adsorption propertiesAdsorption properties of the MIPs were evaluated by carrying out equilibrium binding experiments in artificial seawater sam-ples.The binding kinetics of the imprinted silica gel sorbents for PAHs was examined.It is observed from Fig.3,that the amounts of PAHs adsorbed onto MIPs increased with time and nearly reached saturation state within10h;adsorption rate rapidly increased within7.5h and then slowly increased approximating level off.The high adsorption rate can be ascribed to the preferential and rapid adsorption of PAHs onto the recognition sites in the MIPs.When these imprinted sites were occupied,it became difficult for PAHs to implant into the MIPs.This would cause the adsorption rate to slow down.Although NIPs displayed similar trend to MIPs on the PAHs adsorption,as seen in Fig.3, their adsorption capacity was much lower.The equilibrium absorption capacity for PAHs onto MIPs within10h was 2.7mg gÀ1,while only1.2mg gÀ1onto the corresponding NIPs. This might be likely because of the non-specific adsorption of NIPs,due to the absence of imprinting procedure and thereafter lacking suitable recognition sites and imprinting cavities in the NIPs.In contrast,interestingly,there were a number of precise imprinting sites in the MIPs,resulting in specific adsorption,and thus they produced higher adsorption capacity.The isotherm of Langmuir–Freundlich(LF)equation was con-sidered for evaluating binding characteristics of the synthetic MIPs[37].Experimental data werefitted in LF,and the relation-ship between concentrations of bound(B)and free guests(F)was established as.B¼N t a F m 1þa F mwhere,N t is the total number of binding sites,a is related to the median binding affinity constant(K0)via K0¼a1/m,and m is the heterogeneity index which will be equal to1for a homo-geneous material,or will take values within0and1if the material is heterogeneous.In order to estimate the N t,K0and m values,the isotherm data(F and B)were successfullyfitted according to the LF model(Fig.4),and the resultantfitting coefficients are listed in Table1.As shown in Table1,the value of m demonstrated the higher degree of binding site heterogene-ity of MIPs with the index(m¼0.64)than that of NIPs(m¼0.80). However,the MIPs had the higher concentration of binding sites per gram of polymers(N t¼3031.3m g gÀ1)and median binding affinity(K0¼40.64m g gÀ1).The results indicated that thebinding Fig.2.FT-IR spectra of(a)activated silica gel,(b)non-imprinted silica gel and (c)imprinted silica gel.X.Song et al./Talanta99(2012)75–82 78capacity of the MIPs was much higher than that of the NIPs.Additionally,the plot exhibited saturation at higher concentra-tions,demonstrating the excellent imprinting effect due to a number of specific binding sites on MIPs.3.3.Binding selectivity of the MIPs for PAHsGenerally,the cavities of imprinted sorbent created by the imprinted molecules can lead to much greater affinity for the template molecule,in comparison with non-imprinted sorbent.In several batch experiments,the distribution ratio (K d )wascalculated using the following equation.K d ¼ðF 0ÀF t ÞV F t mwhere,V ,F 0,F t and m represent the volume of the solution (mL),solution concentrations before and after adsorption (m g L À1)and mass of the polymer (m g),respectively.The imprinting factor (IF)is defined as.IF ¼K d ,MIP K d ,NIPTo evaluate the selectivity of the synthesized MIPs,the uptake capacities of the sorbent for 16PAHs were tested,rebinding experiments were performed using a 16PAHs mixture with the initial concentration of 1m g L À1,and the distribution ratios (K d ),equilibrium adsorption (B )and IF were calculated.As seen from Table 2,the K d for the 16PAHs on the MIPs were from 0.78to 1.77L g À1;in contrast,the K d on the NIPs were from 0.37to 0.99L g À1.When compared to NIPs for PAHs,the MIPs have 1.5–3.1fold IF in seawater medium.The MIPs showed high selectivity due to the tailor-made cavity selective for PAHs.The adsorbance of individual PAH to MIPs was found in the range of 111.0to 195.0m g g À1after adsorption equilibrium.Interestingly,the higher IF was exhibited for line type struc-tural PAHs including Nap,Acy,Ace,Flu,Ant,Py,BaA,Ipy,BbF,DahA and BghiP,in contrast with angle type ones including Fl,Phe,Chr,BaP and BkF.Additionally,the results also showed that the binding capacity of BbF to MIPs was the highest (195.0m g g À1),whereas the least one was that of Fl (111.0m g L À1).Considering the properties of lower/higher hydro-phobia (K ow value was 4.18for Fl,and 6.323for BbF),the molecular steric type of angle (Fl)and line (BbF)might explain their lower and higher binding capacity of specific interactions in MIPs for Fl and BbF,respectively.Although there are no pro-nounced functional groups in PAHs,the imprinting process can be performed via special non-covalent interactions between func-tional monomers and PAHs,i.e.the hydrophobic interaction and p –p interaction resulted from the aromatic ring structure of PAHs.Furthermore,it is obvious that the aromatic ring seems to be important for molecular recognition,and the imprinting effect decreased with the angle increase of the angle type PAHs (such as Fl,Phe,Flu,Chr,and BaP).The configurations of the angle type (Fl and Phe)and line type (Ant)were optimized,resulting in the0.03.433.443.453.463.47l o g B (µg g -1)log F (µg L -1)0.20.40.60.8 1.0Fig.4.Binding isotherm and Langmuir–Freundlich model fitting for MIPs.Experi-mental conditions:V ¼10.0mL;mass of polymer,50mg;adsorption time,24h.Table 1LF isotherm model fitting coefficients for MIPs and NIPs.PolymersIsotherm parameters R 2N t /m gg À1a /g m g À1m K 0a /g m g À1MIPs 3031.310.750.6440.640.9968NIPs1667.9 3.780.805.270.9967aThe median binding affinity constant was calculated as K 0¼a 1/m .Table 2Distribution ratio (K d ),adsorption capacity (B ),imprinting factor (IF )of MIPs and NIPs,and octanol/water partition coefficient (log K ow )for PAHs.PAHsMIPs NIPs log K ow aK d /Lg À1B /m gg À1IF K d /Lg À1B /m gg À1Nap 1.31184.2 3.120.4259.2 3.3Acy 1.77194.7 2.190.8189.8 4.0Ace 0.86125.8 2.320.3753.7 3.92Fl 0.78111.0 1.900.4157.8 4.18Phe 1.64176.3 1.910.8692.5 4.45Ant 1.64185.1 2.100.7887.4 4.46Flu 1.37170.0 2.210.6276.3 5.16Py 1.51185.6 2.400.6377.5 5.18BaA 1.66187.1 2.130.7887.4 5.91Chr 1.62172.2 1.840.8893.5 5.86BbF 1.76195.0 2.170.8189.3 6.32BkF 0.99119.3 1.500.6679.8 6.45BaP 1.76177.2 1.780.9999.5 6.04IPy 1.64182.9 2.080.7988.3 6.58DahA 1.48181.4 2.350.6377.7 6.86BghiP 1.35167.7 2.210.6175.9 6.58PPAHs1.3127163.120.421285/alog K ow octanol/water partition coefficient.050010001500200025003000A d s o r b a n c e o f P A H s (µg g -1)Time (h)510152025Fig.3.Kinetic adsorption of PAHs onto MIPs and NIPs.Experimental conditions:V ¼10.0mL;C 0¼1m g L À1;mass of polymer,50mg.X.Song et al./Talanta 99(2012)75–8279lowest energy,by using Hartree–Fock (HF)method with 6–31G basis set [38].As shown in Fig.5,the results demonstrated that the angle type structured molecules such as Fl and Phe in cyclobenzene had lower electron densities than that of line type ones such as Ant,theoretically.So,the concept of ‘‘multiple molecule imprinting’’proposed by Krupadam et al [28]was also successfully demonstrated by using the 16PAHs mix as a template.The formed binding cavities have different binding pocket energies and even smaller molecule may loosely trap in the MIPs but energetically favorable molecule fit properly.3.4.Matrix effectsBecause of the possible strong interference in the trace level PAHs detection caused by presence of other high dissolved matters,it is necessary to study the effect of organic matter and inorganic common ions on the MIPs adsorption for PAHs inseawater samples,and thereby to evaluate the adsorption capa-city of MIPs for PAHs.The observations of matrix effects were shown in Table 3.By using artificial seawater spiked with individual PAH at 1m g L À1and humic acid (HA)at 12mg L À1for testing the influence of dissolved organic matter (DOM),the results revealed that higher level DOM caused a strong inter-ference in trace level detection of specific environmental pollu-tants [39].Effects of inorganic common ions such as Ca 2þ,Mg 2þand Fe 3þon the adsorption capacity of MIPs were also studied because of their universal existence in environmental samples.In artificial seawater,the MIPs binding affinity for PAHs quickly declined at higher concentrations of Mg 2þand Fe 3þcompared to that of Ca 2þ.The results showed that the inorganic cations at higher valance (such as Fe 3þ)or with smaller ionic radius at same valency (such as Mg 2þ)might have the higher polarizability.For ions with the same charges,such as Mg 2þ(ionic radius as 0.065nm)and Ca 2þ(ionic radius as 0.099nm),smaller ion has larger charge density and larger coulombic force;for ions with different charges,such as Ca 2þand Fe 3þ(ionic radius as 0.064nm),higher charge ion has higher charge density.As a result,the MIPs showed diminished adsorption of PAHs when increasing total dissolved ions in environmental samples.There-fore,it is significant and imperative to eliminate the matrix effects for sensitive and accurate determination of PAHs.Excitedly,the binding characteristics of the presented MIPs were still far super-ior to other MIPs for PAHs reported [23,28,40],and should be sufficient for extracting/removing PAHs present at trace level from natural seawater,as shown 93.2%in Table 3.On the other hand,as shown in Table 3,the presence of NaCl at a high concentration even 3%had no obvious effect on adsorption,giving 98.1%efficiency.Salting can enhance extraction of some compounds from water [41].As is well known that,natural seawater usually contains 2.7%NaCl.So it is reasonable to use the 3%NaCl solution to investigate the matrix effects.3.5.MISPE applications to seawater sample for PAHs analysis The applicability of the developed MIPs as SPE sorbent was tested by GC–MS for analysis of PAHs in environmental water samples.To demonstrate the applicability and reliability of MIPs,the spiked standard PAHs seawater samples were cleaned up with MIPs.Natural seawater collected from Zhanshan Beach (Qingdao,China)and artificial seawater were spiked with 1m g L À1PAHs mixture.A pre-weighed amount of 50mg of MIPs or NIPs were padded into the empty SPE columns,respectively,and then a 10mL of seawater sample was filtered,and the SPE column was washed with 10mL of methanol/acetic (1:1,v/v).As seen from Table 4,the recoveries of all the 16PAHs were higher than 82%;the matrix had no significant influence.For the natural seawater samples,the recoveries were in the range of 83–113%withtheFig.5.Optimized configurations and natural charge analysis of Fl,Ant and Phe derived by Hartree–Fock method with 6–31G basis set.Table 3Interference study of environmental parameters-Ca 2þ,Mg 2þ,Fe 3þand HA for PAHs adsorption onto MIPs.Solvent spiked with 1m gL À1PAHsEnvironmental parameters PPAHsadsorbed on MIPs/%Ca 2þ/molL -1Mg 2þ/molL À1Fe 3þ/molL À1HA/mg L À13%NaCl(aq)ÀÀÀÀ98.13%NaCl(aq)0.0650.053ÀÀ86.53%NaCl(aq)0.51ÀÀÀ85.83%NaCl(aq)ÀÀ0.51À53.73%NaCl(aq)À0.51ÀÀ56.13%NaCl(aq)ÀÀÀ12.0047.4Natural seawater 0.050.059.82Â10À83.793.2X.Song et al./Talanta 99(2012)75–8280。

16种多环芳烃结构-回复关于16种多环芳烃结构的文章。

引言：多环芳烃是一类分子结构复杂的有机化合物，其中包含两个或两个以上的芳环结构。

这些化合物普遍存在于石油和煤炭等烃类资源中，也是工业生产和环境污染的重要物质。

本文将详细介绍16种常见的多环芳烃结构，并对其结构特点、来源和环境影响等方面进行一一阐述。

第一部分：三环芳烃三环芳烃是指由三个芳环组成的多环芳烃化合物。

常见的三环芳烃包括芘、蒽和菲。

这些化合物均具有稠密的结构，其分子间存在较大的相互作用力。

芘是一种最简单的三环芳烃，广泛存在于煤炭燃烧等过程中。

第二部分：四环芳烃四环芳烃是指由四个芳环组成的多环芳烃化合物。

常见的四环芳烃包括邻苯二酚、萘和菊花烷。

这些化合物具有相对较大的分子体积和复杂的立体结构，具有较高的识别度和环境稳定性。

第三部分：五环芳烃五环芳烃是指由五个芳环组成的多环芳烃化合物。

常见的五环芳烃包括苯并(a)芘、苯并(b)蒽和苯并(c)芘。

这些化合物结构更加复杂，具有较强的毒性和致突变性，被广泛应用于环境监测和毒性评估中。

第四部分：六环芳烃六环芳烃是指由六个芳环组成的多环芳烃化合物。

常见的六环芳烃包括苯并(α)芘、苯并(β)芘和苯并(γ)芘。

这些化合物具有更高级的结构和较强的亲水性，广泛应用于纳米材料合成、光电子器件等领域。

第五部分：七环芳烃七环芳烃是指由七个芳环组成的多环芳烃化合物。

常见的七环芳烃包括苯并(α)苝、苯并(β)苝和苯并(γ)苝。

这些化合物结构至上复杂，具有较强的吸附能力和高度稳定性，在污染物修复领域具有重要的应用前景。

结论：多环芳烃作为一类具有复杂分子结构和广泛应用领域的有机化合物，对环境和人体健康产生着重要的影响。

了解和研究不同多环芳烃的结构特点、来源和环境影响，对于开展环境监测和环境保护具有重要意义。

通过深入研究16种常见的多环芳烃结构，不仅可以积累环境科学领域的研究经验，还能够为未来的环境治理和工业生产提供理论和技术支持。

16种多环芳烃结构什么是多环芳烃（PAH）？多环芳烃（Polyaromatic Hydrocarbon，简称PAH）是一类由两个或更多个苯环连接在一起的有机化合物。

每个苯环都由六个碳原子和六个氢原子组成，而连接两个苯环的键则由可以是单键、双键或三键构成。

因为其结构独特，PAH分子通常呈环状或碗状结构，并且具有一定的稳定性。

PAH在自然界中广泛存在，可以通过燃烧木材、石油、煤炭等化石燃料产生。

同时，PAH也是一些重要化学反应和工业过程的中间产物，例如焦油的蒸馏和高温热解。

除了天然来源外，PAH还可以由许多人为活动引起的污染物的排放产生，例如汽车尾气、工业废水和废气等。

PAH的类别：1. 双环PAH：由两个苯环组成的PAH，例如萘、甲萘、二甲萘等。

2. 三环PAH：由三个苯环组成的PAH，例如菲、芘、蒽等。

3. 四环PAH：由四个苯环组成的PAH，例如荧蒽、呋喃并蒽等。

4. 五环PAH：由五个苯环组成的PAH，例如蓝蒽、苯并蓝蒽等。

5. 六环PAH：由六个苯环组成的PAH，例如苯并荧蒽、苯并苝等。

6. 七环PAH：由七个苯环组成的PAH，例如苯并芘、苯并蓝苝等。

7. 八环PAH：由八个苯环组成的PAH，例如丁并菲、芘并苝等。

8. 九环PAH：由九个苯环组成的PAH，例如菌螷菌碘、芘爇菌碘等。

9. 十环PAH：由十个苯环组成的PAH，例如菌碘菌碘、菌爇碘菌碘等。

10. 十一环PAH：由十一个苯环组成的PAH，例如螷菌碘菌碘、菌碘菌彣菌彣等。

11. 十二环PAH：由十二个苯环组成的PAH，例如菌碘菌罨菌碘、菌菌爇菌彣菌爇菌罨等。

12. 十三环PAH：由十三个苯环组成的PAH，例如菌碘菌碘爇菌彣菌碘爇菌罨等。

13. 十四环PAH：由十四个苯环组成的PAH，例如菌彣菌刁爇菌爇菌罨等。

14. 十五环PAH：由十五个苯环组成的PAH，例如菌罨菌彣菌菌菌菌菌等。

15. 十六环PAH：由十六个苯环组成的PAH，例如菌罨菌彣菌菌菌菌等。

萘英文名称NAP Naphthalene分子量128.18物理性质；密度1.162 熔点80.5℃,沸点217.9℃,凝固点,80.5℃,闪点78.89℃,折射率1.58212（100℃）恒压燃烧热：40264.1J/g(标准大气压，298.15K）恒压燃烧热：40205J/g(标准大气压，298.15K）。

不溶于水，溶于乙醇和乙醚等。

易挥发，易升华溶于乙醇后，将其滴入水中，会出现白色浑浊。

化学性质（1）萘的氧化温和氧化剂得醌，强烈氧化剂得酸酐。

萘环比侧链更易氧化，所以不能用侧链氧化法制萘甲酸。

电子云密度高的环易被氧化。

（2）萘的还原（3）萘的加成（4）萘的亲电取代反应萘的a-位比b-位更易发生亲电取代反应。

a-位取代两个共振式都有完整的苯环。

b-位取代只有一个共振式有完整的苯环。

在萘环上主要发生亲电取代，同苯环一样，但活性比苯环强从中间对称的两个C旁边的C开始标，其中1，4，5，8号碳活性完全一样（称为阿尔法碳），2，3，6，7号碳性质完全一样（称为贝塔碳）。

一般情况下，阿尔法碳活性大于贝塔碳，取代基在阿尔法位上，这是由动力学控制，温度较高时，阿尔法碳[1]上取代基会转移到贝塔碳上。

但在萘的弗瑞德-克来福特酰基化反应，不加热却生成了阿尔法位和贝塔位的混合物。

如用硝基甲烷为溶剂，则主要生成贝塔酰化产物。

苊烯ANY Acenaphthylene 分子量：152.200性质：黄色棱柱状或板状结晶。

熔点92-93℃，沸点265-275℃（部分分解），156-160℃（3.73千帕），相对密度0.8988（16/2℃），易溶于乙醇、甲醇、丙醇、乙醚、石油醚、苯，不溶于水。

能在强酸中聚合。

苊ANA Acenaphthene 英文别名：1,8-Ethylenenaphthalene 分子量：154.21性状描述：白色或略带黄色斜方针状结晶。

物理参数：密度:1.0242(99/4°C) 熔点:96.2°C 沸点:279°C 闪点:125°C 折射率:1.6048(95°C)芴FLU Fluorene分子量：166.22性状描述：白色叶状至小片状结晶物理参数：密度:1.202 g/mL 熔点:116-117°C 沸点:295°C 闪点:151°C菲PHE Phenanthrene 分子量：178.23性状描述：类白色粉状结晶体。

16种多环芳烃的结构式多环芳烃（PAHs）是一类由两个或更多苯环连接而成的有机化合物。

它们通常由碳和氢原子组成，具有独特的结构和性质。

以下是16种常见的多环芳烃的结构式及其简要描述。

1. 萘（Naphthalene）结构式：C10H8描述：由两个苯环通过共享一个边界碳原子而连接而成。

是最简单的多环芳烃之一，常用于制造染料和防腐剂。

2. 菲（Phenanthrene）结构式：C14H10描述：由三个苯环组成，中间一个环和两个外环共享碳原子形成上下两个七元环。

常出现在石油和煤焦油中。

3. 蒽（Anthracene）结构式：C14H10描述：由三个苯环组成，中间一个环和两个外环通过共享一个边界碳原子形成上下两个六元环。

在化学研究和染料制造中广泛应用。

4. 苯并[α]蒽（Benz[a]anthracene）结构式：C18H12描述：一种四环芳烃，由四个苯环组成。

它的结构类似菲，但其中一个环上有一个附加的苯环。

是一种常见的污染物，对生态系统和人类健康有潜在危害。

5. 萘并[α]蒽（Naphtho[a]anthracene）结构式：C18H12描述：由菲和萘两种结构相连接而成，中间有一个共享的边界碳原子。

在煤焦油和车辆尾气中较为常见。

6. 萘并[β]蒽（Naphtho[b]anthracene）结构式：C18H12描述：由菲和萘两种结构相连接而成，中间有一个共享的边界碳原子。

在煤焦油和多种化学反应中常见。

7. 苯并[α]芘（Benz[a]pyrene）结构式：C20H12描述：由五个苯环组成，其中一个附加苯环连接在其他四个环上。

是一种常见的多环芳烃，被认为是一种强致癌物质。

8. 萘并[α]芘（Naphtho[a]pyrene）结构式：C20H12描述：由菲和芘两种结构相连接而成，中间有一个共享的边界碳原子。

是一种常见的环境污染物，在焦油、煤燃烧和柴油排放物中较多。

9. 苯并[β]芘（Benz[b]pyrene）结构式：C20H12描述：由五个苯环组成，其中一个附加苯环连接在其他四个环上。