多环芳烃的溶解度与双区理论

本文借助于多环芳烃的分配系数与溶解度的关系式,估算了多环芳烃的溶解度,并利用高效液相色谱法间接测定了多环芳烃的溶解度。以双区理论为基础,研究了多环芳烃的溶解度与其致癌性的关系,对双区公式进行了溶解度的补充,得到的公式与戴乾圜的公式计算结果的计算值颇为接近。     

多环芳烃在盐溶液中盐析常数和活度系数的研究

研究盐类对多环芳烃溶解度的影响,不仅涉及盐效应各种理论的研究,而且在化工分离、环境治理上也有重要的实际意义。本文研究了25℃下7种多环芳烃在NaCl水溶液中的活度系数和盐析常数。计算并比较了萘和联苯的盐析常数以及5种多环芳烃在被正辛醇饱和的NaCl水溶液中的活度系数和盐析常数。     

高效液相色谱法测定河道底泥中的多环芳烃

用高效液相色谱法分离测定河道底泥中的多环芳烃，通过梯度淋洗使多种多环芳烃完全分离，并分别得到14种多环芳烃的检出限和线性范围，被试验的4种多环芳烃的回收率为94.1％～103．1％，相对标准偏差为1.00％。2．87％（n=7）。用该方法对小清河东营段的实际底泥样品中多环芳烃的含量进行了测定。     

使用C18固要萃取膜—色质联用定量分析饮用水中痕量多环芳烃的初步 …

参照美国ＥＰＡ５２５．１方法,Ｃ１８－固相萃取膜萃取饮用水中的有机物,利用ＧＣ／ＭＳ法鉴定多环芳烃（ＰＡＨＳ）,使用１６种多环芳烃混合标准样绘制标准曲线,以内标法对ＰＡＨＳ进行定量分析。采用本方法某水厂经过深度处理后的出厂水中的７种多环芳烃的含量,ＰＡＨＳ的平均回收率为９４．０－９７．７％。检测限为０．００１μｇ／Ｌ。     

不同垃圾焚烧炉排放的PM10 中多环芳烃的研究

对大气可吸入颗粒物采样器进行改装，建立了垃圾焚烧炉烟气中PM10采样系统，并采集了三家垃圾发电厂焚烧炉排放烟气中的可吸入颗粒物。利用GC-MS对可吸入颗粒物中的16种多环芳烃进行定量研究，获得了多环芳烃的质量分数和浓度，并对不同环数的芳烃进行了比较，分析了不同样品中的多环芳烃的毒性参数。结果表明，颗粒物中的多环芳烃主要集中在4环、5环和6环，3环和2环所占比例较少；与燃煤电厂相比，垃圾焚烧发电厂排放的烟气中多环芳烃的浓度和毒性参数更高。     

超临界流体分级萃取正构烷烃和多环芳烃

本工作用超临界ＣＯ２对环境模拟样品中的正构烷烃和多环芳烃的超临界分级萃取方法及超临界ＣＯ２的压力，温度和用量对分级效率的影响进行了详细的研究。结果表明，在低压、低温下（８０ＭＰａ，５０℃）能成功地分级萃取正构烷烃和多环芳烃，其Ｃ１０～Ｃ１８的萃取率为９９．９４％～５９．２８％，而多环芳烃基本未被萃取。当压力升至２６．０ＭＰａ、温度升至８０℃时，可有效地萃取多环芳烃，实现了正构烷烃和多环芳烃的有效分离     

南四湖水中多环芳烃的分析及分布研究

采用固相萃取结合气相色谱-质谱(GC-MS)方法对南四湖水中13种多环芳烃进行了分析。南四湖水中检出的多环芳烃以二环、三环为主,检出的6种多环芳烃中相对含量较高的是菲、芴和苊,多环芳烃总浓度范围为0.004~3.53μg/L。入湖河口各点浓度比湖内点位低,上级湖的入湖河口含量高于下级湖的入湖河口,且湖内各点位多环芳烃的含量按湖水流向逐渐降低。     

固相萃取搅拌棒萃取-气相色谱分析海水中的多环芳烃

利用固相萃取搅拌棒（SBSE）萃取海水中的多环芳烃，然后用热解吸脱附-气相色谱分析。研究了萃取时间、添加NaCl浓度对萃取效率的影响。实验结果表明，SBSE方法对16种多环芳烃的萃取回收率分别在33．5％～122．4％之间；对标准样品的检出限为2．74-13．5ng／L；方法RSD为3．8％～13．1％。用此方法测定了大连海岸海水中的多环芳烃含量。     

用自制新型端羟基冠醚固相微萃取涂层快速监测水中痕量多环芳烃

采用溶胶—凝胶技术，加入自制的新化合物端羟基冠酸，成功地涂制了固相微萃取涂层；用半挥发性的有机污染物多环芳烃评价了涂层的基本性能，并对实际水样中的多环芳烃进行了分析。该方法的线性范围在0．1—10μg／L，检出限在0．001—0.03μg/L，8种多环芳烃化合物测定的相对标准偏差在2．05％一9．80％，回收率在85％以上。     

用固相萃取技术富集水中多环芳烃

系统地研究了淋洗剂强度、用量和有机改性剂的加入对固相萃取水中多环芳烃回收率的影响。研究表明,二氯甲烷和苯的洗脱效果较好,回收率为８７％～１０２％;当淋洗剂的用量超过１．５ｍＬ时,对多环芳烃的回收率没有明显的影响;向自来水样中加入２０％有机改性剂可明显改善多环芳烃的回收效果,使回收率达到８９％～１０８％。     

分子拓扑学方法估算多环芳香烃类化合物的电离能

It was found that the ionization potentials (Ip) is related with the polarizability effect index (PEI) for the fragments CH, CH2, and CH3 of polycyclic aromatic hydrocarbon. Therefore a kind of adjacent matrix of molecular graph was constructed, in which the characteristics of the diagonal elements were expressed with the PEI of the fragments C, CH, CH2, and CH3 in molecular graph. The research result shows that there is a good correlation between the eigenvalue of the matrix and the ionization potential for the title compounds: Ipi=4.756+2.870OMOi, R=0.9853, s=0.1765, n=446. This new calculation method has only one parameter for calculating ionization potentials of polycyclic aromatic hydrocarbon. The obtained result shows that the topologic molecular method is convenient and reliable.     

Quantification of 16 polycyclic aromatic hydrocarbons in cigarette smoke condensate using stable isotope dilution liquid chromatography with atmospheric‐pressure photoionization tandem mass spectrometry

A stable isotope dilution liquid chromatography tandem mass spectrometry method for the analysis of 16 polycyclic aromatic hydrocarbons in cigarette smoke condensate was developed and validated. Compared with previously reported methods, this method has lower limits of detection (0.04–1.35 ng/cig). Additionally, the proposed method saves time, reduces the number of separation steps, and reduces the quantity of solvent needed. The new method was applied to evaluate polycyclic aromatic hydrocarbon content in 213 commercially available cigarettes in China, under the International Standardization Organization smoking regime and the Health Canadian intense smoking regime. The results showed that the total polycyclic aromatic hydrocarbon content was more than two times higher in samples from the Health Canadian intense smoking regime than in samples from the International Standardization Organization smoking regime (1189.23 versus 2859.50 ng/cig, p < 0.05). Meanwhile, the concentration of individual polycyclic aromatic hydrocarbons (and total polycyclic aromatic hydrocarbons) increased with labeled tar content in both of the tested smoking regimes. There was a positive correlation between total polycyclic aromatic hydrocarbons under the International Standardization Organization smoking regime with that under the Health Canadian intense smoking regime. The proposed liquid chromatography tandem mass spectrometry method is satisfactory for the rapid, sensitive, and accurate quantitative evaluation of polycyclic aromatic hydrocarbon content in cigarette smoke condensate, and it can be applied to assess potential health risks from smoking.     

An Additivity Scheme for Aromaticity: The Heteroatom Case

The nucleus-independent chemical shift (NICS)-XY-Scan is a simple and easy tool for the quantitative measurement of the aromaticity of polycyclic aromatic hydrocarbons and identification of the existence of local and global ring currents. We recently introduced an additivity scheme that uses the NICS-XY-Scans of smaller building blocks to predict the aromatic profiles of larger polycyclic aromatic hydrocarbon systems. We now report on an expansion of the methodology to include systems of varying aromatic natures containing the heteroatoms B, N, O, and S. The additivity approach allows for rapid and resource-efficient generation of NICS-XY-Scans of large, complex systems. Moreover, it reveals that the magnetic criterion of aromaticity behaves in an additive manner, and that the ring currents of multi-ring systems appear to be mostly localized within subunits of up to three rings.     

System for calculating the linear temperature-programmed retention indices of polycyclic aromatic compounds

Theoretical procedures have been used to predict linear temperature-programmed retention indices for polycyclic aromatic compounds. It is possible to calculate such indices for polycyclic aromatic compounds in some practical situations in which the compounds cannot be eluted during a simple linear temperature program. The theory has been tested for a number of polycyclic aromatic hydrocarbon (PAHs) in single- and multi-plateau temperature-programmed gas chromatography with SE-52 as the stationary phase. This method will extend the applicability of linear retention indices for the identification of the isomers of polycyclic aromatic compounds.     

Reliability assessment of a gas chromatographic method for polycyclic aromatic hydrocarbons in olive oil.

A quality control test was developed for a gas chromatographic method to determine polycyclic aromatic hydrocarbons in olive oil. Fifteen oil specimens were fortified with eight three- to six-ring polycyclic aromatic hydrocarbons at levels of between 3.0 (approximate detection limit) and 360 micrograms/kg. Three sets of five equally fortified specimens were obtained and assayed at random by three operators. For each fortification level, the means of recovery yield were in the range 56-107%, and were independent of the polycyclic aromatic hydrocarbon congener specificity and the operator's capability. Excluding subsets of data associated with both the fortification level at the detection limit and a deviant polycyclic aromatic hydrocarbon term (benzo[ghi]perylene), an overall mean accuracy of 96% and a precision of 7% were achieved.     

Unexpected Michael Additions on the Way to 2.3,8.9‐Dibenzanthanthrenes with Interesting Structural Properties

The synthesis and properties of a new polycyclic aromatic hydrocarbon containing eight annulated rings and based on the anthanthrene core is described. An unexpected, nucleophile‐dependent Michael addition to a dibenzanthanthrene‐1,7‐dione is found, giving a product with three triisopropylsilylacetylene units and a remarkable solid‐state structure (as determined by X‐ray crystallography).     

para‐Quinodimethane‐Bridged Perylene Dimers and Pericondensed Quaterrylenes: The Effect of the Fusion Mode on the Ground States and Physical Properties

Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para‐quinodimethane (p‐QDM)‐bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7 , were synthesized. Their ground‐state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p‐QDM‐bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (?2.97 kcal mol^?1), whereas the antiaromatic s‐indacene‐bridged N‐annulated perylene dimer 5 exists as a closed‐shell quinoid with an obvious intramolecular charge‐transfer character. Both of these dimers showed shorter singlet excited‐state lifetimes, larger two‐photon‐absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7 , respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.     

Determination of Trace Amounts of Organic Pollutants in the Yellow River by Capillary Column Gas Chromatography-Mass Spectrometry

Abstract

The trace organic pollutants in the Yellow River enriched by a solvent extraction method were pre-separated into four different fractions of fatty hydrocarbons, polycyclic aromatic hydrocarbons, polar compounds and organic acids and were analyzed by the use of combined capillary column gas chromatography-mass spectrometry. Using the combined techniques of relative retention value, mass spectra and mass chromatogram, more than 60 organic pollutants were identified, among which 16 fatty hydrocarbons and 6 polycyclic aromatic hydrocarbons which were quantitatively analyzed. The concentration range of fatty hydrocarbon was 5–800 ng/l, and that of polycyclic aromatic hydrocarbon was 0-90ng/l.     

聚合物包覆二氧化锆液相色谱固定相的制备与评价

在溶液体系中通过自由基引发长链碳烯-1、二乙烯苯和乙烯基二氧化锆交联聚合反应得到聚长链碳烯-苯乙烯包覆二氧化锆固定相.考察了这种交联聚合物包覆柱填料的色谱性能和化学稳定性,并用这种填料分离了稠环芳烃和碱性化合物.     

Photostability of electronically excited polyacenes: a case study of vibronic coupling in the naphthalene radical cation

Novel issues of electronic nonadiabatic coupling in the excited state dynamics of prototypical naphthalene radical cation of polycyclic aromatic hydrocarbon of the polyacene family are theoretically investigated. A benchmark ab initio quantum dynamical study is performed and its complex vibronic spectra and nonradiative decay are examined. The findings are in very good accord with the experiment, unambiguously establishing the crucial role of intricate electron-nuclear coupling in the photoinduced dynamical processes of this system.