Metal-free naphthannulation reactions of yne-allenone esters for accessing polycyclic aromatic hydrocarbons

2018 ◽  
Vol 54 (74) ◽  
pp. 10415-10418 ◽  
Author(s):  
Hong-Kai Sha ◽  
Ting Xu ◽  
Feng Liu ◽  
Bu-Zheng Tang ◽  
Wen-Juan Hao ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Free Base ◽  
Metal Free ◽  
Direct Assembly ◽  
Wide Range ◽  
Polycyclic Aromatic

The first metal-free base-promoted naphthannulation reactions of yne-allenone esters were developed for the direct assembly of a wide range of polycyclic aromatic hydrocarbons with generally good yields.

scholarly journals The Role of Methyl Groups in the Early Stage of Thermal Polymerization of Polycyclic Aromatic Hydrocarbons Revealed by Molecular Imaging

2020 ◽  
Author(s):  
Pengcheng Chen ◽  
Shadi Fatayer ◽  
Bruno Schuler ◽  
Jordan N. Metz ◽  
Leo Gross ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Early Stage ◽  
Complex Mixture ◽  
Thermal Polymerization ◽  
Industrial Applications ◽  
Thermal Reactions ◽  
Force Microscopy ◽  
Wide Range ◽  
Polycyclic Aromatic

The initial thermal reactions of aromatic hydrocarbons are relevant to many industrial applications. However, tracking the growing number of heavy polycyclic aromatic hydrocarbon (PAH) products is extremely challenging because many reactions are unfolding in parallel from a mixture of molecules. Herein, we studied the reactions of 2,7-dimethylpyrene (DMPY) to decipher the roles of methyl substituents during mild thermal treatment. We found that the presence of methyl substituents is key for reducing the thermal severity required to initiate chemical reactions in natural molecular mixtures. A complex mixture of thermal products including monomers, dimers, and trimers were characterized by NMR, mass spectrometry and non-contact atomic force microscopy (nc-AFM). A wide range of structural transformations including methyl transfer and polymerization reactions were identified. A detailed mechanistic understanding was obtained on the roles of H radicals during the polymerization of polycyclic aromatic hydrocarbons.

Comparison of Polycyclic Aromatic Hydrocarbons Exposure Across Occupations Using Urinary Metabolite 1-Hydroxypyrene

2020 ◽  
Vol 64 (4) ◽  
pp. 445-454
Author(s):  
Dong-Hee Koh ◽  
Ju-Hyun Park ◽  
Sang-Gil Lee ◽  
Hwan-Cheol Kim ◽  
Sangjun Choi ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Coke Production ◽  
Geometric Standard Deviation ◽  
Occupational Groups ◽  
Skin Cancers ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
High Fraction ◽  
Pah Exposure

Abstract Objectives Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogens causing lung and skin cancers in exposed workers. Certain occupations, such as coke production, have been associated with high PAH exposure; however, the number of occupations tested to date remains small. Here, we sought to compare PAH exposure across a wide range of occupations based on levels of 1-hydroxypyrene (1-OHP), the urinary exposure surrogate of PAHs. Methods We collected urine 1-OHP data from the Korean National Environmental Health Survey (KoNEHS), a nationwide biomonitoring survey. We developed a linear regression model, controlling for sex, age, smoking, and survey cycle, and obtained resulting residuals. Then, we computed the fraction of exceeding the third quartile (Q3) level of residuals for each occupation, which is employed as a relative exposure indicator across occupations. Results A total of 15 125 measurements derived from three cycles of KoNEHS were used for analysis. The overall geometric means (GMs) and geometric standard deviation (GSD) of urine 1-OHP levels were 0.16 µg g−1 creatinine and 3.07, respectively. Among the sub-major occupational groups, ‘construction and mining related elementary occupations’ showed the highest fraction (0.45) of exceeding the Q3 level of residuals. Among the minor occupational groups, ‘deliverers’ showed a high fraction (0.42) of exceeding the Q3 level of residuals, which indicates rapidly growing occupations to be addressed. Conclusions Our results provide ancillary information regarding PAH exposure across occupations, especially for occupations for which PAH exposure has not been well characterized.

scholarly journals Polycyclic aromatic azomethine ylides: a unique entry to extended polycyclic heteroaromatics

2015 ◽  
Vol 6 (1) ◽  
pp. 436-441 ◽  
Author(s):  
Reinhard Berger ◽  
Manfred Wagner ◽  
Xinliang Feng ◽  
Klaus Müllen
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Azomethine Ylides ◽  
Metal Free ◽  
Polycyclic Aromatic

Based on polycyclic aromatic azomethine ylides, a metal-free “cycloaddition-planarization-sequence” is proposed, providing a unique entry to nitrogen-containing polycyclic aromatic hydrocarbons.

Cross hybridization of plasmid and genomic DNA from aromatic and polycyclic aromatic hydrocarbon degrading bacteria

1991 ◽  
Vol 37 (12) ◽  
pp. 924-932 ◽  
Author(s):  
J. M. Foght ◽  
D. W. S. Westlake
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Genomic Dna ◽  
Bacterial Strains ◽  
Cross Hybridization ◽  
Pah Degradation ◽  
Naphthalene Degradation ◽  
Degrading Bacteria ◽  
Wide Range ◽  
Polycyclic Aromatic

Forty-three bacterial strains were collected from various environmental and commercial sources and their ability to degrade polycyclic aromatic hydrocarbons (PAHs) was confirmed using the criteria of growth, mineralization, and oxidation. Undigested genomic DNA from these strains was blotted by Southern transfer to replicate membranes, which were probed either with purified plasmids (e.g., TOL and NAH7, associated with toluene and naphthalene degradation, respectively) or with genomic DNA from the other strains. The isolates were grouped according to hybridization and PAH-degradation results. One group of eight strains grew on naphthalene vapors as sole carbon source and hybridized with archetypical NAH plasmids. Another group of six isolates mineralized phenanthrene but could not grow on naphthalene, and their cryptic plasmids hybridized with Pseudomonas sp. HL7b, which degrades a wide range of PAHs. The remaining isolates, which could not grow on naphthalene but mineralized and (or) oxidized a variety of PAHs, hybridized with neither the pure plasmids nor heterologous genomic DNA, implying that their PAH-degradative genes were significantly dissimilar. This suggests that using TOL or NAH plasmids to probe an environmental population might reveal toluene- or naphthalene-degradative genes but would underestimate the occurrence of PAH-degradative genes. We suggest that a suite of probes would be necessary to evaluate the PAH-degradation potential of a mixed population. Key words: polycyclic aromatic hydrocarbons, degradative plasmids, NAH plasmid, TOL plasmid, hybridization.

Distribution of polycyclic aromatic hydrocarbons in snow particulates around Longyearbyen and Barentsburg settlements, Spitsbergen

Polar Record ◽  
2016 ◽  
Vol 52 (6) ◽  
pp. 645-659 ◽  
Author(s):  
Anna Abramova ◽  
Sergei Chernianskii ◽  
Nataly Marchenko ◽  
Elena Terskaya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Snow Cover ◽  
Aromatic Hydrocarbons ◽  
Airborne Particulate Matter ◽  
Svalbard Archipelago ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Snow Mass ◽  
Southwest Part

ABSTRACTContamination of snow cover has been investigated in the Longyearbyen (78°13 N, 15°38 E) and Barentsburg (78°3 N, 14°12 E) areas, which are situated in the southwest part of Spitsbergen (Svalbard archipelago). Snow cover was sampled in two winter seasons, 2012–2013 and 2013–2014, at 54 locations within potentially contaminated areas. Sampling incorporated the whole snow mass and was combined with morphological observations as well as thickness and density measurements. Meltwater and suspended solids were further analysed for a wide range of contaminants including polycyclic aromatic hydrocarbons (PAHs) and macro-ions. Results were contrasted with previous studies measuring the release of contaminants from snow to soil cover. It was shown in keeping with earlier studies that PAH contributions are associated with airborne particulate matter. The results, in contrast to earlier studies further demonstrated that the high concentrations of contaminants in both settlements are attributed to local sources due to combustion and industrial activity.

scholarly journals A Novel Protocol to Monitor Trace Levels of Selected Polycyclic Aromatic Hydrocarbons in Environmental Water Using Fabric Phase Sorptive Extraction Followed by High Performance Liquid Chromatography-Fluorescence Detection

2017 ◽  
Author(s):  
Shivender Singh Saini ◽  
Abuzar Kabir ◽  
Ashok Kumar Malik ◽  
Avasarala Lakshmi Jagannadha Rao ◽  
Kenneth Furton
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Water Samples ◽  
Environmental Water ◽  
Detection Sensitivity ◽  
Environmental Water Samples ◽  
Sorptive Extraction ◽  
Relative Standard ◽  
Wide Range ◽  
Polycyclic Aromatic

Fabric phase sorptive extraction (FPSE) combines the advanced material properties of sol–gel derived microextraction sorbents and the flexible and permeable fabric support to create a robust, simple and green sample preparation device. It simultaneously improves the extraction sensitivity, and the speed of the extraction by incorporating high volume of sponge-like porous sol–gel hybrid inorganic–organic sorbents into permeable fabric substrates that is capable of extracting target analytes directly from simple to complex aqueous sample matrices. For the first time, this technique was applied to the trace level determination of selected polycyclic aromatic hydrocarbons (PAHs) in environmental water samples using a non-polar sol–gel C18 coated FPSE media. Several extraction parameters were optimized to improve extraction efficiency and to achieve high detection sensitivity. Validation tests of spiked samples showed good linearity for four selected PAHs (R2 = 0.9983–0.9997) over a wide range of concentrations (0.010-10 ng/mL). Limits of detection (LODs) and quantification (LOQs) were measured at pg/mL levels, 0.1–1 pg/mL and 0.3–3 pg/mL, respectively. Inter- and intra-day precision tests showed variations of 1.1–4.1% for four selected PAHs. Average absolute recovery values were in the range of 88.1–90.5% surpassed the recovery prediction model, with relative standard deviations below 5%. The developed FPSE-HPLC-FLD protocol was finally applied to analyze 8 environmental water samples. Out of four selected PAHs, fluoranthene (Flu) and phenanthrene (Phen) were the most frequently detected in four samples, at concentration levels of 5.6–7.7 ng/mL and 4.1-11 ng/mL, respectively followed by anthracene (Anth) and pyrene (Pyr) in two samples. The newly developed FPSE-HPLC-FLD protocol is simple, green, fast and economical, with adequate sensitivity for trace levels of four selected PAHs and seems to be promising in routine monitoring of water quality and safety.

scholarly journals Application of QuEChERS for Determining Xenobiotics in Foods of Animal Origin

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Coralia V. Garcia ◽  
Ahmed Gotah
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Veterinary Drugs ◽  
Small Samples ◽  
Animal Origin ◽  
Animal Products ◽  
Wide Range ◽  
Recent Developments ◽  
Polycyclic Aromatic

The use of pesticides and veterinary drugs results in the appearance of residues of xenobiotics in foods. Thus, several methods have been developed for monitoring them; however, most are tedious and expensive. By contrast, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methodology involves a microextraction that yields small samples and has been applied for the analysis of various xenobiotics including pesticides, antibiotics, and mycotoxins. QuEChERS has shown advantages over other techniques including fast sample preparation, reduced needs for reagents and labware, and versatility. This approach allows the simultaneous determination of pesticides with various polarities and volatilities and can be easily modified for the analysis of a wide range of xenobiotics in various matrices including animal products rich in fat. Nevertheless, to attain high recoveries, the extraction, cleanup, and concentration steps have to be optimized according to the target compounds and matrix. Hence, QuEChERS is a promising and environmentally friendly methodology for the high-throughput routine analysis of xenobiotics in animal products. This review focuses on the application of QuEChERS to foods of animal origin and describes recent developments for the optimization of the analysis of veterinary drugs, pesticides, polycyclic aromatic hydrocarbons, and other compounds of concern.

Degradation of polycyclic aromatic hydrocarbons and aromatic heterocycles by a Pseudomonas species

1988 ◽  
Vol 34 (10) ◽  
pp. 1135-1141 ◽  
Author(s):  
J. M. Foght ◽  
D. W. S. Westlake
Keyword(s):  
Gas Chromatography ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Capillary Gas Chromatography ◽  
Pseudomonas Sp ◽  
Aromatic Heterocycles ◽  
Wide Range ◽  
Pseudomonas Species ◽  
Polycyclic Aromatic ◽  
Cryptic Plasmids

Enrichment cultures were established with the aromatic fraction of a crude oil and screened for aromatic-degrading pseudomonads, using a sprayed plate technique. One isolate identified as Pseudomonas sp. HL7b was chosen for further study because it oxidized several polycyclic aromatic hydrocarbons and aromatic heterocycles without an apparent lag. Using capillary gas chromatography, spectrophotometry, and radiorespirometry, it was found to be capable of mineralizing and (or) oxidizing a wide range of polycyclic aromatic hydrocarbons, S-, N-, and O-heterocyclic analogues, and alkyl polycyclic aromatic hydrocarbons, but not aliphatic hydrocarbons. The isolate displayed two colonial morphologies which correlated with variation in degradative phenotype and hydrophobicity as measured by polystyrene adherence. Four cryptic plasmids were observed in both colonial types. Pseudomonas sp. HL7b degraded dibenzothiophene co-metabolically by a recognized pathway, but this degradation was constitutive, rather than inducible as reported for other bacteria.

An atom- and pot-economical consecutive multi-step reaction approach to polycyclic aromatic hydrocarbons (PAHs)

2017 ◽  
Vol 53 (11) ◽  
pp. 1904-1907 ◽  
Author(s):  
Chada Raji Reddy ◽  
Uredi Dilipkumar ◽  
Ravula Shravya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Reaction Conditions ◽  
Metal Free ◽  
Polycyclic Aromatic

A novel [4+2]-benzannulation approach to substituted polycyclic aromatic hydrocarbons has been developed under atom-economical, mild and metal-free reaction conditions.

Sign in / Sign up

Export Citation Format

Share Document