scholarly journals Formation Mechanism of Benzo(a)pyrene: One of the Most Carcinogenic Polycyclic Aromatic Hydrocarbons (PAH)

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1040 ◽  
Author(s):  
Edina Reizer ◽  
Imre Csizmadia ◽  
Árpád Palotás ◽  
Béla Viskolcz ◽  
Béla Fiser
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Growth Mechanism ◽  
Aromatic Hydrocarbons ◽  
Energy Levels ◽  
Chemical Species ◽  
Polycyclic Aromatic ◽  
Global Concern ◽  
The Difference ◽  
Intramolecular Hydrogen ◽  
Deep Exploration

The formation of polycyclic aromatic hydrocarbons (PAHs) is a strong global concern due to their harmful effects. To help the reduction of their emissions, a crucial understanding of their formation and a deep exploration of their growth mechanism is required. In the present work, the formation of benzo(a)pyrene was investigated computationally employing chrysene and benz(a)anthracene as starting materials. It was assumed a type of methyl addition/cyclization (MAC) was the valid growth mechanism in this case. Consequently, the reactions implied addition reactions, ring closures, hydrogen abstractions and intramolecular hydrogen shifts. These steps of the mechanism were computed to explore benzo(a)pyene formation. The corresponding energies of the chemical species were determined via hybrid density funcional theory (DFT), B3LYP/6-31+G(d,p) and M06-2X/6-311++G(d,p). Results showed that the two reaction routes had very similar trends energetically, the difference between the energy levels of the corresponding molecules was just 6.13 kJ/mol on average. The most stable structure was obtained in the benzo(a)anthracene pathway.

scholarly journals Hidrocarburos Aromáticos Policíclicos (HAPs) en ambientes marinos: Una revisión de América

2020 ◽  
Vol 1 (2) ◽  
pp. 19-40
Author(s):  
T. Recabarren-Villalón ◽  
M.M. Orazi ◽  
J.E. Marcovecchio ◽  
A.H. Arias
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Environmental Concern ◽  
Original Research ◽  
Marine Environments ◽  
Multiple Sources ◽  
Coastal Marine ◽  
Polycyclic Aromatic ◽  
Global Concern ◽  
Monitoring Activity

The polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds of global concern. They pres-ent mutagenic and carcinogenic characteristics, in addition to a wide variety of other adverse effects in the or-ganisms. They are widely distributed in marine environments, implying several health risks for both ecosystems and public health. Therefore, require constant monitoring and tailoring of preventive measures for their control. This review is based on the PAHs original research within coastal-marine environments published along the past ten years in America, considering the main environmental matrix such as sediment, water, organisms, and air. The review shows an outstanding PAHs monitoring activity led by USA and Mexico –at all matrix-, followed by Argentina, Brazil and Chile which demonstrate a rising environmental concern on these compounds, focused in highly anthropized areas. The present data for South America is still scarce, including many areas with null information. This review demonstrates that along all the continent and all matrixes, detectable concentrations of PAHs from multiple sources are reported, with levels ranging from minimum to extremely high. Keywords: Polycyclic aromatic hydrocarbons (PAHs), marine environments, America.

scholarly journals The Influence of Different Smoking Procedures on the Content of 16 PAHs in Traditional Dry Cured Smoked Meat “Hercegovačka Pečenica”

Foods ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 690 ◽  
Author(s):  
Leona Puljić ◽  
Krešimir Mastanjević ◽  
Brankica Kartalović ◽  
Dragan Kovačević ◽  
Jelena Vranešević ◽  
...  
Keyword(s):  
Surface Layer ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Meat Products ◽  
Total Content ◽  
Pork Meat ◽  
Limit Of Quantification ◽  
Polycyclic Aromatic ◽  
The Difference ◽  
Inner Parts

During smoking, meat products may get contaminated by polycyclic aromatic hydrocarbons (PAH), especially the ones that are smoked in traditional (uncontrolled) conditions. This study aims to evaluate the difference in PAH content in samples of traditional dry cured pork meat products, “Hercegovačka pečenica”, produced in (1) a traditional smokehouse and (2) in industrial chambers. The study revealed that the content of the four priority PAHs (PAH4) in samples produced in a traditional smoking manner highly exceeded (up to 10 times) the maximal limits set for PAHs (12 µg/kg). PAH4 in all samples subjected to industrial smoking procedures was below the limit of quantification. All samples had below-the-limit-of-quantification values for Benzo[a]pyrene. The surface layer of the samples produced in traditional conditions had the highest total content of PAH16. The inner parts of all samples, whether traditional or industrial, had significantly lower PAH16 concentration than the surface layer.

scholarly journals Downward fluxes of elemental carbon, metals and polycyclic aromatic hydrocarbons in settling particles from the deep Ionian Sea (NESTOR site), Eastern Mediterranean

2013 ◽  
Vol 10 (7) ◽  
pp. 4449-4464 ◽  
Author(s):  
C. Theodosi ◽  
C. Parinos ◽  
A. Gogou ◽  
A. Kokotos ◽  
S. Stavrakakis ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Mediterranean Sea ◽  
Aromatic Hydrocarbons ◽  
Elemental Carbon ◽  
Eastern Mediterranean ◽  
Chemical Species ◽  
Sea Surface ◽  
Ionian Sea ◽  
Eastern Mediterranean Sea ◽  
Polycyclic Aromatic

Abstract. To assess sources and major processes controlling the vertical transport of both anthropogenic and natural chemical species in a deep basin of the Eastern Mediterranean Sea (SE Ionian Sea, Nestor site), we performed chemical characterization (elemental carbon, major and trace metals and polycyclic aromatic hydrocarbons) of marine sinking particles. Sediment traps were deployed at five successive depths, 700, 1200, 2000, 3200 and 4300 m from the sea surface from May 2007 to October 2008. Fluxes of all measured chemical species, attributed to both natural and anthropogenic sources, exhibited minimum values from January to March 2008 and maximum from April to September 2008. Crustal matter flux from atmospheric inputs – either "freshly" deposited or stored in the surface layers – plays an important role in the temporal variability of particulate marine matter fluxes along with particulate organic carbon export, imposing ballast effects. Tracers (elemental carbon, retene) of the devastating forest fires that occurred in August 2007 in southern Greece were detected in sediment trap material from all depths with a delay of 15 days at 4300 m, indicating a rapid and well-coupled transport of sinking particulate material between the sea-surface and deep layers of the Eastern Mediterranean Sea. This is in accordance with an evident covariance between certain compounds, suggesting common sources and/or transport mechanisms to depth. Lateral inputs of pollutants at the deepest trap (4300 m) are probably of importance, related to the periodic influence of deep Adriatic water at the study site.

scholarly journals Access tetracoordinate boron-doped polycyclic aromatic hydrocarbons with aggregation-induced emission under mild conditions

2021 ◽  
Author(s):  
Long Jiang ◽  
Dehui Tan ◽  
Xiaobin Chen ◽  
Tinghao Ma ◽  
Baoliang Zhang ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Functional Groups ◽  
Aromatic Hydrocarbons ◽  
Coupling Reactions ◽  
Optoelectronic Materials ◽  
Aggregation Induced Emission ◽  
Boron Doped ◽  
Polycyclic Aromatic ◽  
The Difference ◽  
Oxidative Coupling Reactions

The boron-doped polycyclic aromatic hydrocarbons (PAHs) have attracted ongoing attention in the field of optoelectronic materials due to their unique optical and redox properties. To investigate the effect of tetracoordinate boron in PAHs bearing N-heterocycles (indole and carbazole), a facile approach to four-coordinate boron-doped PAHs was developed, which does not require elevated temperature and pre-synthesized functionalized boron reactants. Five tetracoordinate boron-doped PAHs (NBNN-1 – NBNN-5) were synthesized with different functional groups. Two of them (NBNN-1 and NBNN-2) could further undergo oxidative coupling reactions to form fused off-plane tetracoordinate boron-doped PAHs NBNN-1f and NBNN-2f. Compared to the three-coordinate boron-doped counterparts, the UV/Vis absorption and fluorescent emission are significantly red-shift. Unlike the distinct impact of coordination number of boron on optoelectronic properties, the difference of functional groups on the boron atom has negligible impact on their optical and electrochemical properties. The compounds NBNN-1f and NBNN-2f show aggregation-induced emission.

scholarly journals Polycyclic aromatic hydrocarbons in water samples from a Nigerian bitumen seepage: Gas chromatography- mass spectrometry quantification

2018 ◽  
Vol 53 (4) ◽  
pp. 319-326
Author(s):  
AU Itodo ◽  
R Sha’Ato ◽  
MI Arowojolu
Keyword(s):  
Gas Chromatography ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Limit Of Detection ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Polycyclic Aromatic ◽  
Pahs Concentration ◽  
The Difference ◽  
And Control

Bitumen exploration was flagged off at Irele, a Nigerian field in 2003. The relationship between the seepage pollutants and receiving water bodies is the focus of this study. We hereby present the polycyclic aromatic hydrocarbons (PAHs) level in two categories of bitumen contaminated waters; source (RS) and delivery (RD) points. Results were compared with uncontaminated water (RC) as control experiment. The PAHs were extracted by Liquid-Liquid extraction using dichloromethane and analyzed by Gas chromatography with mass spectrometer detector (GC-MS). The mean concentration of PAHs was 8.39, 3.93 and 0.57 ppb for source, delivery point and control respectively. The Benzo[e]pyrene concentrations obtained were higher than 1-10 ppb in most samples, indicating anthropogenic and petrogenic sources of the pollutants. Most of the PAH concentrations obtained were within natural concentrations, However, Benzo (e) pyrene and Indenol (1, 2, 3 – cd) pyrene exceeded the expected limit. The predominance of 4-6 member ring showed that the PAHs were more of pyrolytic than mixed sources. Method validation gave the Limit of Detection (LOD) and Limit of Quantification values in the range of 0.03-0.12 and 0.10-0.61 respectively. The Pearson product moment correlation (PPMC) coefficient (r) was used to determine the interactions of the PAHs detected with parametric factors. All the physicochemical parameters studied except pH shows positive correlation. Statistical test at P <0.05 indicated that the difference in PAHs concentrations is not significant when compared with maximum acceptable PAHs concentration (MAC) for water, which is an indication that the water is safe.Bangladesh J. Sci. Ind. Res.53(4), 319-326, 2018

Influence of PAHs on ligninolytic enzymes of the fungus Pleurotus ostreatus D1

2010 ◽  
Vol 5 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Natalia Pozdnyakova ◽  
Svetlana Nikiforova ◽  
Olga Turkovskaya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Pleurotus Ostreatus ◽  
Degradation Products ◽  
Ligninolytic Enzymes ◽  
Versatile Peroxidase ◽  
Cultivation Medium ◽  
Polycyclic Aromatic ◽  
The Difference ◽  
Pleurotus Ostreatus D1

AbstractPolycyclic aromatic hydrocarbons (PAHs), their derivatives, and their degradation products were assayed for the ability to enhance activities of ligninolytic enzymes (laccase and versatile peroxidase) of the fungus Pleurotus ostreatus D1. The activities of both laccase and versatile peroxidase were induced by the PAHs, their derivatives, and their degradation products. Laccase was produced mostly in the first 7–10 days, whereas the production of versatile peroxidase began after 5–7 days of cultivation. Non-denaturing PAGE showed the presence of additional forms of laccase and versatile peroxidase in the presence of the xenobiotics in the cultivation medium. The difference in the production time for these enzymes may reflect that laccases are involved in the first stages of PAHs degradation and that versatile peroxidase can be necessary for oxidation of some degradation products. This is the first report on versatile peroxidase induction by PAHs and their derivatives.

Sign in / Sign up

Export Citation Format

Share Document