THE CHEMISTRY AND ANALYSIS OF LARGE PAHs

A large economic problem in petroleum processing, the plugging of catalytic hydrocracking units, led to a study of the production of large polycyclic aromatic hydrocarbons (PAHs) in this process. Through that work, many other studies of PAHs happened. These included the analysis of coal tar pitches, hydrothermal-vent bitumens, carbon black, Diesel particulate, and fullerene soots. Many new PAHs were synthesized or isolated during the course of these many studies.     

多环芳烃含量限制法规及测试方法比较

详细介绍多环芳烃（PAHs）含量限制法规及相关测试标准,对各标准的PAHs含量测试方法和测试范围进行比较,说明其特点。以实验室实际测试为例,阐述不同PAHs含量测试方法的特征以及数据的解读。     

Polycyclic aromatic hydrocarbons (PAHs) in soot produced by combustion of polystyrene,polypropylene, and wood

The smoke and soot produced by the combustion of plastics or wood in a domestic stove or fireplace contain many poisonous compounds, including the polycyclic aromatic hydrocarbons (PAHs), many of which are carcinogenic. PAHs were selected as the subject of our study to gain a better sense of the hazards of burning plastics. Small samples of polystyrene, polypropylene, and wood underwent combustion in a tubular oven at 700°C; in addition, polystyrene and wood were combusted at room temperature. After their extraction and purification, the PAHs were analyzed by gas chromatography and mass spectrometry. Conditions in the hot oven promoted soot production, whereas combustion at room temperature led to somewhat more complete combustion. The PAH profiles of the examined materials resembled each other to some extent, though the original chemical structure of the polymeric materials varied a great deal. However, clear differences between the materials could be detected from the soot extracts, the soot of polystyrene being especially rich in compounds containing remnants of the polymer structure. Carcinogenic activity caused by the PAHs can be assumed to be of the same order of magnitude as soot from the combustion of wood.     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

Analysis of Polycyclic Aromatic Hydrocarbons in Egyptian Petroleum Condensate Oils

The polycyclic aromatic hydrocarbons (PAH) in Egyptian condensates are analyzed for the first. A solid phase extraction (SPE) followed by gas chromatography-mass selective detection was used for their analysis. The method was calibrated for optimal extraction conditions. Excellent recoveries were found (78–114%) for the PAHs that were identified using a variety of standards and GC-MS spectra. The solid-phase extracted PAH fraction was further separated by HPLC on a Ag(I) mercaptopropanosilica gel to reduce the complexity of the sample by separating the PAHs based on the number of aromatic rings. The analytes were quantified using GC with a flame ionization detector. For this kind of sample SPE is a more convenient separation technique than an open column. PAHs containing two to four rings in the concentration range 0.6–11 μg/L were measured. Some preliminary geochemical hypotheses based on the analyzed PAHs and the previously analyzed S-containing aromatic compounds were formed as to the depositional environment and source rock type.     

Recertification of Standard Reference Material (SRM) 1649, Urban Dust,for the Determination of Polycyclic Aromatic Hydrocarbons (PAHs)

The National Institute of Standards and Technology (NIST) recently issued SRM 1649a, Urban Dust, with certified and reference values for 44 polycyclic aromatic hydrocarbons (PAHs). This material is a recertification of SRM 1649 which was issued in 1982 with certified values for only five PAHs. The PAHs were determined using the following analytical techniques: (1) reversed-phase liquid chromatography with fluorescence detection (LC-FL) for analysis of the total PAH fraction, (2) reversed-phase LC-FL for analysis of isomeric PAH fractions isolated by normal-phase LC (i.e., multidimensional LC), and (3) gas chromatography/mass spectrometry (GC/MS) for analysis of the PAH fraction using three different stationary phases, each with different selectivity for PAH separations. The results from the different techniques are compared and discussed. SRM 1649a is currently the most extensively characterized environmental matrix SRM with respect to PAH constituents.     

民用燃煤颗粒物及多环芳烃排放特性

民用煤的不完全燃烧是大气中颗粒物及其多环芳烃的主要排放源之一,对大气环境和人体健康均造成了严重危害。为了评价不同“煤炉匹配”方式对16种优先控制的高毒性多环芳烃（PAHs）排放的影响,研究了烟煤块煤、烟煤型煤、无烟煤型煤和兰炭4种不同燃料在代表性的3种民用炉具（正烧炉、反烧炉和解耦燃烧炉）中的颗粒物（PM）及其PAHs的排放特性。根据实验结果进一步计算了毒性当量,并与有关文献报道数据进行了对比。在解耦燃烧炉中,烟煤型煤PM和PAHs的排放因子（EF_PM 和EF_PAHs）（0.50 g/kg、403.2 μg/kg）分别是烟煤块煤（3.65 g/kg、989.6 μg/kg）、兰炭（1.08 g/kg、622.3 μg/kg）、无烟煤型煤（2.10 g/kg、148.3 μg/kg）的13.7%、46.3%、23.8%和42.3%、67.3%、282.3%,除了EF_PAHs高于无烟煤型煤之外,EF_PM 和EF_PAHs均明显低于其他煤种;以烟煤块煤为原料,在解耦炉中燃烧的EF_PM 和EF_PAHs（3.65 g/kg、989.6 μg/kg）分别是正烧炉（46.58 g/kg,16182.3 μg/kg）和反烧炉（6.00 g/kg,11749.4 μg/kg）的7.8%、60.8%和6.1%、8.4%,说明炉具燃烧形式对EF_PM和EF_PAHs的影响大于燃料种类;三种“煤炉匹配“方式（解耦炉+烟煤型煤、正烧炉+兰炭、正烧炉+无烟煤型煤）的EF_PM和EF_PAHs（0.50 g/kg、1.62 g/kg、1.32 g/kg和403.2 μg/kg、1196.5 μg/kg、66.5 μg/kg）均低于传统正烧炉+烟煤块煤（46.58 g/kg,16182.3 μg/kg）以及近年来大部分文献报道的数据（0.68~24.3 g/kg,680~137700 μg/kg）。结果表明,炉具燃烧形式和煤质特性均是影响EF_PM和EF_PAHs的主要因素,但高效的燃烧方式能够大幅降低煤质特性对污染物排放造成的影响,通过对炉具的不断改进以及采用合适的“煤炉匹配”技术,能够对我国储量巨大的烟煤资源合理、有效和清洁地利用。     

GC-MS测定乌参中多环芳烃残留

建立了气相色谱-质谱法（GC-MS）同时测定乌参中20种多环芳烃残留的方法。样品经蒸馏水混合和二氯甲烷萃取,浓缩,硅胶层析柱净化,外标法定量。20种多环芳烃得到较好的分离,回收率为92.0%~103.0%,相对标准偏差（RSD）为1.86%~4.62%,检出限10μg/kg。实验结果表明,该方法简单、快速、重现性好,能满足乌参中多环芳烃残留的测定要求。     

Beyond 16 Priority Pollutant PAHs: A Review of PACs used in Environmental Forensic Chemistry

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in soils and sediments, particularly in urbanized environments in which the concentrations of 16 (or so) PAHs are regulated. Distinguishing among the numerous PAH sources is of practical and legal concern and thereby is often an objective of environmental forensic chemistry studies. Studies of prospective sources and impacted soils and sediments that rely upon the 16 U.S. EPA Priority Pollutant PAHs are disadvantaged, as these few compounds generally lack the specificity to distinguish among different PAH sources in the environment. Advances in analytical and interpretive methods over several decades have shown that different PAH sources can be more defensibly distinguished using modified EPA Method 8270 that, among other improvements, measure many other polycyclic aromatic compounds (PACs) that co-occur with the Priority Pollutant PAHs in different sources and in the environment. The PACs include variously-alkylated PAHs and polycyclic aromatic sulfur heterocyclics (PASHs) homologs and individual isomers, which are herein reviewed. Collectively, these PACs provide a higher degree of specificity among PAC sources and can be used to understand the effects of weathering on PAH assemblages. Despite their diagnostic capacity, PACs should not be relied upon at the exclusion of other compound groups (e.g., petroleum biomarkers) in most environmental forensic chemistry studies. In light of these advances, source characterization studies that rely only upon the 16 (or so) Priority Pollutant PAHs warrant considerable caution.     

微波萃取-GC／MS法分析测定塑料中多环芳烃

建立了塑料中16种美国环境保护局（EPA）优先监控的多环芳烃的气相色谱-质谱（GC／MC）联用分析方法。样品经微波萃取后,再经硅胶柱净化,用GC／MS分离测定。优化了16种多环芳烃（PAHs）的分离测定条件．结果16种PAHs的平均回收率为64．2％-95．6％,精密度实验RSD为0．8％-6．2％,检测限（S／N为3）为0．001～0．01mg／kg。该方法灵敏度高、准确性好,完全可以满足塑料多环芳烃的检测要求。     

The Spatial and Temporal Variations of Polycyclic Aromatic Hydrocarbons (PAHs) in Environmental Matrices in the Czech Republic

The paper is a review of the PAH emission inventories and the results of ambient air measurements of PAHs on regional a local level and determination of PAHs in other abiotic and biotic samples in the Czech Republic (CR). The main sources of polycyclic aromatic hydrocarbons (PAHs) in the country are associated with electric and thermal energy production, waste incineration, road traffic and some industrial processes (e. g. high-temperature coal carbonation, catalytic cracking of crude oil and aluminium production).     

Comparison of the Concentration Profiles of 12 Polycyclic Aromatic Hydrocarbons from Different Sources with Monitoring Data from Prague Using a Similarity Measure

A method not used yet for detection of similarity between polycyclic aromatic hydrocarbon (PAH) profiles was applied to selected air samples taken in three localities of Prague. Dissimilarities between PAHs profiles in the Prague atmosphere, solid fuel (coal or wood) combustion, vehicle exhaust, and vehicle exhaust in a traffic tunnel atmosphere indicates that there are other sources of PAHs in the atmosphere of Prague.     

DEVELOPMENT OF AN ISOTOPE-DILUTION GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC METHOD FOR THE ANALYSIS OF POLYCYCLIC AROMATIC COMPOUNDS IN ENVIRONMENTAL MATRICES

An isotope-dilution GC-MS (GC-IDMS) method for the analysis of polycyclic aromatic hydrocarbons (PAHs) in various environmental matrices, including soils, sediments and an extended application to air particulate, has been developed. This method allows for the quantification of each target analyte against its isotope-labelled analogue as well as for the correction of analyte recovery during sample preparation and analysis. Using isotope-dilution mass spectrometric analysis, the isotope-labelled internal standards can significantly reduce systematic error (bias) from several sources including sample stability prior to analysis, analyte loss during both the extraction procedure and post-extraction sample workup and from the calibration procedure. Sample analysis and quantification was carried out using a multi-point calibration technique with continuing single-point calibration (daily single-point checks of the calibration) in order to assess daily instrumental performance; various other new quality control measures have also been employed. Faster methods of gas chromatographic analysis were evaluated using different types of GC columns, stationary phases and methods of detection. Overall, this method has improved the quality and accuracy of PAH data produced and has significantly reduced the time required for sample preparation.     

轮胎中多环芳烃的检测技术

概述欧盟2005／69／EC指令【多环芳烃（PAHs）指令】和欧盟REACH法规对轮胎中有PAHs含量的限制。介绍气相色谱、气相色谱一质谱、高效液相色谱、液相色谱一质谱和核磁共振等检测方法在PAHs检测中的应用。分析核磁共振检测PAHs的特点和ISO21464：2012与ISO21464：2009中核磁共振检测方法的差异,提出我国轮胎企业应采用与欧盟环保法规同步的核磁共振法检测PAHs。     

Sulphur heterocycles in coal-derived products: Relation between structure and abundance

Sulphur heterocycles in a coal tar and in a coal liquid vacuum residue were isolated by ligand exchange chromatography using PdCl₂ on silica gel. Subsequent fractions were analysed by capillary column gas chromatography and gas chromatography-mass spectrometry. Two new selective stationary phases (a smectic liquid-crystalline polysiloxane and a biphenyl polysiloxane), as well as a methylpolysiloxane, were used to resolve the numerous isomers. All major sulphur heterocycles with 3–6 rings were identified by comparison of retention times of mixture components with those of standard reference compounds. The structures and relative abundances of the major sulphur heterocycles were analogous to those of the major polycyclic aromatic hydrocarbons in the same or similar samples.     

Standard Reference Materials (SRMs) for the Determination of Polycyclic Aromatic Compounds--Twenty Years of Progress

In 1981 the National Bureau of Standards, now the National Institute of Standards and Technology (NIST), issued the first natural matrix Standard Reference Material (SRM) for the determination of polycyclic aromatic compounds (PACs), SRM 1580 Organics in Shale Oil. In the next 10 years, additional natural matrix SRMs were developed including air and diesel particulate matter, petroleum crude oil, coal tar, sediment, and mussel tissue. The SRMs represented the "first generation" of natural matrix SRMs for the determination of PACs. The SRMs had "certified" values for only 5 to 12 PACs; however, their development established the foundation for the implementation of the "two or more independent analytical techniques" approach for certification of individual PACs in environmental matrices. The requirement for use of different analytical techniques spurred the development of both gas chromatography (GC) and liquid chromatography (LC) approaches for the determination of PACs. Since the mid-1990s, the "second generation" of natural matrix SRMs has been issued by NIST with certified values for over 20 PACs in each material. The greater number of certified values in these SRMs was the result of the combination of measurements using reversed-phase LC with fluorescence detection, multidimensional LC, and GC with mass spectrometric detection using two or more stationary phases with different selectivity for polycyclic aromatic hydrocarbon (PAH) separations. This article discusses the significant developments in analytical methods and chromatographic separation of PAHs during the past 20 years that have resulted in the certification of over 25 SRMs, which are now used worldwide for the validation of analytical methods for the measurement of PACs in environmental matrices.     

高效液相色谱法测定水源中苯并芘的方法研究

多环芳烃(PAHs)是煤,石油,木材,烟草,有机高分子化合物等有机物不完全燃烧时产生的挥发性碳氢化合物,是重要的环境和食品污染物。本方法是通过对高效液相色谱仪的开发应用,完成生活饮用水/水源水中苯并芘的方法研究,初步建立地下水污染地质调查评价阶段有机污染物测定方法的技术体系。     

Levels of Some Persistent Organic Pollutants (PCBs and PAHs) in Jordanian Oil Shale Ash after Direct Heating at Different Temperature Ranges

The levels of 13 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) were studied in oil shale ash samples gathered after heating oil shale samples collected from major deposit sites in Jordan. All analyses were carried out using GC/MS instrument. The results showed that the total concentration of the studied polycyclic aromatic hydrocarbon (PAHs) was the highest (75.99–317.53 μg /kg) at the lowest temperature range (200–400°C) and it decreased as the temperature increased. For the heating temperature range 400–600°C the concentrations were all decreased to below the limit of quantification while none of the samples contained any of the studied PAHs at the highest temperature range 600–800°C. While all the analyzed samples did not contain any of the studied 13 compounds of PCBs at different temperature ranges.

Recoveries of PAHs and PCBs were found between 82–106% and 91–114%, respectively. Precision of the analytical method for both PAHs and PCBs, calculated as relative standard deviation (RSD), ranged from 0.95–7.08% and 0.78–9.03%, respectively. The limit of detection values for PAHs and PCBs were between 0.006–0.070 μg/kg and 0.149–0.330 μg/kg, respectively.

The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 9.13 × 10^?7 to 2.15 × 10^?6. By multiplying these numbers of cancer risks of exposure to oil shale ash sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (2 out of 1 million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency.     

新疆典型地区土壤/松针中多环芳烃分布特征

考察了新疆典型地区(石河子、北屯和喀纳斯)土壤和松针中多环芳烃(PAHs)的浓度水平和分布特征。与国内外典型地区相比,新疆土壤和松针中PAHs的污染水平较低。与受人类活动影响明显的石河子地区相比,人迹罕至的喀纳斯地区土壤和松针中低分子量PAHs的比例较高,而高分子量PAHs的比例较低,不同环数PAHs呈现出明显的“局部分馏”现象。PAHs在土壤/松针中的分布系数与其过冷液体饱和蒸气压具有显著的对数线性关系,表明PAHs在土壤/松针中的分布受其物理化学参数的影响,PAHs在土壤/相似文献   

Behavior of Three- to Four-Ring PAHs in the Presence of Oil Shale Ash and Aluminosilicate Matter

Ash generated by oil shale combustion contains polycyclic aromatic hydrocarbons (PAHs) hazardous for environment and human health. The leaching of three- to four-ring PAHs sorbed on oil shale ash and zeolite NaA used as reference matter was investigated. The uptake of PAHs on ash was linearly correlated with the molecular surface area and K ow . The ash and zeolite have similar specific surface area and different characteristics of pores contribution to the total pore volume. The sorption capacity of ash for PAH was four times less than that of aluminosilicate. PAHs sorbed on ash particles leached more readily than those on zeolite. After 3 hr the amount of leached PAHs was 89.6% for phenanthrene and 30% for less-soluble anthracene. In field conditions during the disposing time, the mineral composition and sorptive capacity of ash may change and affect the mobility of PAHs.