Comparative Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Different Parts of Perilla frutescens (L.) Britt.

Perilla frutescens (L.) Britt., a medicinal herb and edible plant, is very popular among East Asian countries. The perilla leaves, stems and seeds can be used as traditional medicines and foods. Polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) are organic pollutants that are widely present in the environment, such as in water, air and soil, and are harmful to humans. In this study, the contents of 16 PAHs and 4 HPAHs in perilla leaves, stems and seeds were determined by gas chromatography tandem mass spectrometry (GC-MS). A total of 12 PAHs were detected in all samples, and no HPAHs were detected. The total contents of PAHs in perilla leaves, stems and seeds varied from 41.93 to 415.60 ng/g, 7.02 to 51.52 ng/g and 15.24 to 180.00 ng/g, respectively. The statistical analyses showed that there were significant differences in the distribution of PAHs in perilla leaves, stems and seeds. On the basis of the toxic equivalent quantity (TEQ) and incremental lifetime cancer risk (ILCR) model, the cancer risks of the intake of perilla leaves, stems and seeds were assessed to be from 3.30 × 10⁻⁸ to 2.11 × 10⁻⁵, 5.52 × 10⁻⁹ to 5.50 × 10⁻⁸ and 1.20 × 10⁻⁸ to 1.41 × 10⁻⁷, respectively. These were lower than 10⁻⁴ (the priority risk level of the EPA) and suggested that there may be almost no cancer risk from the intake of these traditional Chinese medicines (TCMs).     

Determination of Heavy Polycyclic Aromatic Hydrocarbons (PAH) in Drinking Water,Ambient Air,Soils, Sediments and Food Stuffs by HPLC Method with Fluorescence Detection

The methods for the determination of some heavy PAH in different objects by HPLC method with fluorescence detection have been developed. The following conditions for the separation of PAH have been chosen:The column 150 mm length, internal diameter 2.1 mm filled by reversible-phase sorbent Zorbax ODS (5 μ),mobile phase acetonutrile/water (80:20), the injected volume of sample concentrate 10 μ L, the velocity of mobile phase 200 μ L.min. The excitation region is 290-300 nm, the emission one is 350-420 nm. Under condition chosen the limit of detection are 5 pg for benz(a)pyrene,10 pg for pyrene and chrysene3 pg for benz(k)fluoranthene, and 20 pg for anthracene. The dynamic range is 3 order of magnitude. The reproducibility of peak highs is better than 5%.     

The Application of Perdeuterated Polycyclic Aromatic Hydrocarbons (PAH) as Internal Standards for the Liquid Chromatographic Determination of PAH in a Petroleum Crude Oil and Other Complex Mixtures

Abstract

A sequential liquid chromatographic (LC) procedure for the determination of polycyclic aromatic hydrocarbons (PAH) in a petroleum crude oil and other complex mixtures is described. The procedure includes normal-phase LC on an aminosilane column to isolate fractions containing isomeric PAH and reversed-phase LC on a polymeric C₁₈ column to separate the individual PAH isomers. Appropriate perdeuterated PAH are added to the sample so that each isomeric fraction will contain one internal standard. The perdeuterated PAH are excellent internal standards for this sequential LC procedure. Perdeuterated PAH have normal-phase and reversed-phase LC retention characteristics similar to those of the parent PAH. In the normal-phase LC separation, the perdeuterated PAH elute in the same fraction as the parent PAH. In the reversed-phase LC separation, the perdeuterated PAH elute first and are generally resolved from the parent PAH. The optimized spectrofluorometric detection of each PAH analyte is accomplished by programming appropriate sets of excitation and emission wavelengths to correspond with the elation time of each analyte on the polymeric C₁₈ column. The analytical results obtained from this procedure for the analysis of a shale oil sample [Standard Reference Material (SRM) 1580] and a petroleum crude oil (SRM 1582) are compared to values obtained by gas chromatography - mass spectrometry.     

Characterization of Hapten-Protein Conjugates for Immunoassay of Polycyclic Aromatic Hydrocarbons（PAHs）

Preparation and characterization of the hapten-protein conjugates are fundamental to developing environmental immunoassays. As a hapten, 1-pyrenebutyric acid（PBA） was conjugated to the carrier protein of bovine serum albumin（BSA） or ovalbumin（OVA） by active ester method. Infrared spectra（IR） showed that PBA-BSA and PBA-OVA conjugates were successfully prepared. The number of the haptens conjugated to the carrier protein was determined by ultraviolet spectra（UV） and matrix-assisted laser desorption ionization time-of-flight mass spectrometry（MALDI-TOF-MS）. The calculated average binding ratios of PBA/BSA and PBA/OVA were 18：1 and 10：1 by UV, and 31：1 and 22：1 by MALDI-TOF-MS, respectively. Although there was a discrepancy between the results determined by the two methods, both of them were useful for the characterization of the hapten-protein conjugates. The antibody was produced against the antigen of PBA-BSA, and the affinity was tested by the double agar diffusion method The conjugates and the antibody could be used for developing a sensitive and selective immunoassay of polycyclic aromatic hydrocarbons（PAHs）.     

In Situ Correlations Between Polycyclic Aromatic Hydrocarbons (PAH) and Pah Metabolizing System Activities in Mussels and Fish in the Mediterranean Sea: Preliminary Results

Abstract

Biochemical indices based on enzymatic activities have been determined in fish and mussels sampled in various different coastal locations in the Mediterranean Sea. Preliminary results show a good agreement between biochemical measurements in marine organisms and chemical analyses of polycyclic aromatic hydrocarbons present in sediments. The results obtained suggest the use of biochemical indices for application in chemical contaminant biomonitoring.     

Graphene Grown from Flat and Bowl Shaped Polycyclic Aromatic Hydrocarbons on Cu(111)

The growth of carbon layers, defective graphene, and graphene by deposition of polycyclic aromatic hydrocarbons (PAHs) on Cu(111) is studied by scanning tunneling microscopy and X-ray photoelectron spectroscopy. Two different PAHs are used as starting materials: the buckybowl pentaindenocorannulene (PIC) which contains pentagonal rings and planar coronene (CR). For both precursors, with increasing sample temperature during deposition, porous carbon aggregates (350 °C), dense carbon layers (400–450 °C), disordered defective graphene (500 °C–550 °C), and extended graphene (≥600 °C) are obtained. No significant differences for defective graphene grown from PIC and CR are observed. C 1s X-ray photoelectron spectra of PIC and CR derived samples grown at 350–550 °C exhibit a characteristic C−Cu low binding energy component. Preparation at ≥600 °C eliminates this C−Cu species and only C−C bonded carbon remains.     

Packed high-performance GC-columns (about 50000 HETP) for profile analysis of carcinogenic polycyclic aromatic hydrocarbons in foods, mineral oil products, vehicle exhaust- and cigarette smoke condensate etc.

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Suitability of basic zinc carbonate for the analysis of pesticide residues

     

多环芳烃分子结构的距边矢量表征及其气相色谱保留指数预测

 从分子图论拓扑学角度出发 ,提出用六元素组成的分子距边矢量VMDE表达上百个多环芳烃化学结构 ,对 10 0种多环芳烃的毛细管气相色谱保留值进行定量相关性研究 ,发现存在良好的线性相关关系 :IR=a +bVMDE,n =10 0 ,r =0 .988,其中a ,b为回归系数 ,可用于多环芳烃的色谱保留指数的分子建模与定量预测。     

Characterization and Identification of Polycyclic Aromatic Hydrocarbons in Diesel Particulate Matter

Emission of toxic exhaust from diesel engines is one of the major problems associated with the use of petroleum fuels. Particulate matter emission is perceived as a major pollutant, detrimental to the human health and environment, and has led to considerable study. Vehicular emissions comprise toxic pollutants that include unburnt hydrocarbons, polycyclic aromatic hydrocarbons, dioxins, and others. In this study, experiments have been carried out with the objective of determining overall particulate matter chemical composition and size. Electron microscopic images of the emitted soot were studied for average particle size distribution. More than 50 percent of the particles were in the range of 25 to 35 nanometers. Approximately 7, 9, 16, and 5 percent of the measured particles were from 35 to 40, 40 to 45, 45 to 50, and 50 to 55 nanometers, respectively. Determined elements were Al, Ba, Ca, K, Mg, Ti, Zn, and Zr at concentrations of 727, 53, 1100, 701, 1145, 638, 177, and 800 micrograms per milliliter respectively. Fifteen polycyclic aromatic hydrocarbons were detected in the extracts of filters and their concentrations were estimated. This investigation allows the comparison of particulate matter from different fuels and their blends.     

致癌性多环芳烃萘、蒽、芘的分析方法比较

利用薄层色谱（TLC）、紫外光谱（UV）、反相高效液相色谱（RPHPLC）对多环芳烃（PAHs）萘、蒽、芘的分析方法进行了研究。TLC中使用环己烷：氯仿（5：4,V／V）作为展开剂时,三者的R,值分别为0．78、0．65和0．72;用UV法在溶液中测定了三者的最大吸收波长分别为303、380、338nm;当流动相为甲醇：水（9：1,V／V）时三者在RP—HPLC中的保留时间为4．179、5．190、6．178min,5次重复RSD分别为1．1％、1．8％、0．91％,并用于实际水样中萘、蒽、芘的分析。     

二维多环全苯芳烃的合成、性能及应用

二维多环全苯芳香烃(PBAH)具有类似于石墨的结构形态,拥有良好的稳定性,被视作一种理想的导电材料,自问世以来受到了广泛关注。本文详细总结了由树枝形聚苯前驱体平面化而制得PBAH的合成方法, 指出了PBAH的表征难点,阐述了PBAH的多功能性如热致液晶性、导电性以及光学性能,展示了PBAH在电子传输材料、场效应晶体管、光伏电池、发光二极管、二次电池等方面的应用前景。特别指出了带有柔性侧链的PBAH分子可以形成碟状的液晶态,从而呈现有序的超分子结构,在各种PBAH光电材料的应用中占据领先地位。     

超声提取/气相色谱-质谱法测定海洋生物中的多环芳烃

建立了海洋生物体中16种优先控制多环芳烃的超声提取/气相色谱-质谱测定方法,对海洋鱼类、虾类、贝类和蟹类等生物样品的提取、净化和色谱质谱条件进行了优化。以正己烷-二氯甲烷(2∶1)作为溶剂进行超声提取,提取液经60%硫酸溶液和中性氧化铝-弗罗里硅土混合层析柱净化,采用气相色谱-质谱法定性和定量分析。在优化条件下,16种多环芳烃的线性范围为0.005～0.500 mg/L,相关系数(r)不低于0.998 4,检出限为0.03～0.28μg/kg。加标水平为2、20、100μg/kg时,平均加标回收率分别为55%～118%、80%～114%和79%～113%,相对标准偏差(RSDs,n=6)均小于10%。该方法快速、准确、灵敏度高、重复性好,能满足海洋生物体中持久性有机污染物分析的要求。     

A Routine Method for the Quantitative Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban Air

Abstract

We have developed a method for the quantitative determination of polycyclic aromatic hydrocarbons (PAHs) present in urban air, which can be performed rather quickly, and which uses a minimal amount of solvents.

Air samples were collected using a home-made low-volume air sampler equipped with glass fibre filter and polyurethane foam plugs. After Soxhlet extraction a liquid-liquid partition was carried out to isolate the PAH fraction. This liquid-liquid partition was performed in micro-scale, enabling us to use small quantities of the solvents and to separate the solution layers very rapidly using a centrifuge. Sample clean-up was accomplished on a high performance liquid chromatograph equipped with two normal phase silica columns. The losses of all investigated PAHs occurring during the various steps of sample clean-up have been determined. The qualitative and quantitative determination of the PAHs was carried out by capillary gas chromatography; the results were confirmed by GC/MS measurements.

The analytical procedure described was applied over a period of one year to measure the concentrations of 21 PAHs in the city of Vienna at a site with high traffic density. The concentrations of the four more volatile PAHs were determined on a semi-quantitative basis. The ratio of two selected PAHs was used to estimate the respective contribution of traffic and domestic heating to the total PAH level at the sampling site.     

Photochemical Degradation of Polycyclic Aromatic and Nitroaromatic Hydrocarbons in the Urban Atmosphere

Possible mechanisms of the photochemical conversion of polycyclic aromatic and nitroaromatic hydrocarbons in the urban atmosphere under the action of sunlight were analyzed. A kinetic model of the process was proposed, which takes into account the emission of harmful substances and the deposition of these substances onto the Earth's surface. It was found that emission is a predominant process within the bounds of a city. Beyond the precincts of a city, the concentrations of these hydrocarbons decrease because of photochemical degradation. In this case, the rate of this process for compounds adsorbed by soot particles is much higher than the corresponding value for compounds that occur in the gas phase. The results of calculations were compared with measurement data.     

蔬菜中多环芳烃的GC-MS分析

针对蔬菜中多环芳烃(PAHs)基质复杂、检测干扰太大的问题,采用正己烷-丙酮混合溶剂进行索氏提取,提取液经氢氧化钾皂化,硅胶-氧化铝层析柱净化后,用GC-MS进行检测。检出限较低(<0.04μg/kg),回收率稳定(平均值为75%~82%),相对标准偏差为1.1%~14.6%,是测定蔬菜中16种PAHs的较好方法。     

Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Indigenous Mixed and Pure Cultures Isolated from Coastal Sediments

Applied Biochemistry and Biotechnology - The goal of this paper was to quantify and characterize microorganisms (bacteria) in sediment samples contaminated with polycyclic aromatic hydrocarbons...