Petroleum Research Today is a free monthly online journal that collates and summarizes the latest research about Petroleum, including details on crude oil, extraction, chemistry, pollution.

A comparison of concentrations of polycyclic aromatic compounds detected in dust samples from various regions of the world.

Naspinski C, Lingenfelter R, Cizmas L, Naufal Z, He LY, Islamzadeh A, Li Z, Li Z, McDonald T, Donnelly KC

School of Rural Public Health, Texas A&M University System Health Science Center, College Station, Texas, 77843, United States.

Settled house dust can be a source of human exposure to toxic polycyclic aromatic hydrocarbons (PAHs) through non-dietary ingestion and dermal contact. Information regarding the concentrations of various contaminants in house dust would be useful in estimating the risk associated with exposure to these compounds. This study reports on the surface loading, variability and distribution of PAHs in settled house dust collected from homes in three locations: Sumgayit, Azerbaijan; Shanxi Province, China; and southern Texas, United States. The highest PAH floor surface loadings were observed in China, followed by Azerbaijan and Texas. Median concentrations of high molecular weight (four ring and larger) PAHs ranged from a low of 0.11 microg/m(2) in Texas, to 2.9 microg/m(2) in Azerbaijan and 162 microg/m(2) in China. These trends in total surface loading and relative carcinogenicity indicate that the risk of health effects from exposure to PAHs in house dust is highest in the Chinese population and lowest in the Texas population. As anticipated, variability among dust samples from different houses within the same region was high, with coefficients of variation greater than 100%. Alkylated PAHs comprised 30-50% of the total mass of PAHs. Based on a comparison of the composition of specific components, PAHs in China and Azerbaijan were determined to be derived mainly from combustion sources rather than from unburned fossil fuels such as petroleum. These results, coupled with ongoing investigation of appropriate PAH exposure biomarkers in humans, will guide future efforts to identify ways to reduce exposures in the study areas.

Published 2 May 2008 in Environ Int.
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Articles on Petroleum published 2 May 2008:

The effects of different catalysts on the pyrolysis of industrial wastes (olive and hazelnut bagasse).   Bioresour Technol.

Pyrolysis of olive and hazelnut bagasse biomass samples with two selected catalysts, namely activated alumina and sodium feldspar, have been conducted in a fixed-bed reactor. Experiments were carried out under certain pyrolysis conditions in a fixed-bed Heinze reactor. The catalyst was mixed with feedstock in different percentages. The effects of catalysts and their ratio (10%, 20%, 30% and 40% w/w) on the pyrolysis product yields were investigated and the results were compared with the results ... [Abstract] [Full-text]

Articles on Petroleum published 30 April 2008:

Application of analytical and preparative high-speed counter-current chromatography for the separation of Z-ligustilide from a crude extract of Angelica sinensis.   Phytochem Anal, 19(3): 193-7.

Z-Ligustilide was separated and purified from the traditional Chinese medicinal plant Angelica sinensis by high-speed counter-current chromatography (HSCCC). Analytical HSCCC was first used for the systematic selection of the two-phase solvent system. Preparative HSCCC separation was performed with a two-phase solvent system composed of petroleum ether (60-90 degrees C)-ethanol-water at an optimum volume ratio of 10:17:10 (v/v). A total of 38 mg Z-ligustilide at 98.8% purity was obtained in one ... [Abstract] [Full-text]

Articles on Petroleum published 28 April 2008:

Petroleum: a series of 25 cases.   Homeopathy, 97(2): 83-8.

This study is based on 25 well documented reports of cases which responded well to treatment with Petroleum. Materia medica data were compared with results in contemporary clinical practice. Many patients had characteristic skin problems; children often had recurrent or chronic upper respiratory tract problems. The most prominent mental feature is a quiet, withdrawn or stubborn disposition. The mental symptoms may be difficult to recognise. Detailed documentation in daily practice can be ... [Abstract] [Full-text]

Articles on Petroleum published 25 April 2008:

Effect of salt on aerobic biodegradation of petroleum hydrocarbons in contaminated groundwater.   Biodegradation.

Hydrocarbon-contaminated soil and groundwater at oil and gas production sites may be additionally impacted by salts due to release of produced waters. However, little is known about the effect of salt on the in-situ biodegradation of hydrocarbons by terrestrial microbes, especially at low temperatures. To study this effect, we prepared a groundwater-soil slurry from two sites in Canada: a former flare pit site contaminated with flare pit residue (Site A), and a natural gas processing facility ... [Abstract] [Full-text]

Mosquito larvicidal activity of gluanol acetate, a tetracyclic triterpenes derived from Ficus racemosa Linn.   Parasitol Res.

The larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone, and methanol extracts of the leaf and bark of Ficus racemosa (Moraceae) was assayed for their toxicity against the early fourth-instar larvae of Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24-h exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in bark acetone extract of F. racemosa. In the present study, ... [Abstract] [Full-text]

Characterization of Surfactin Produced by Bacillus subtilis Isolate BS5.   Appl Biochem Biotechnol.

Physical and chromatographic characterization of the surfactin biosurfactant produced by Bacillus subtilis isolate BS5 has been conducted to study its potentiality for industrial application. The crude extract of test surfactin appeared as off-white to buff flake-like amorphous residue with bad odor similar to sour pomegranate. Test surfactin showed solubility in aqueous solution at pH > 5 with optimum solubility at pH 8-8.5. It was also soluble in organic solvents like ethanol, acetone, ... [Abstract] [Full-text]

Articles on Petroleum published 24 April 2008:

Development and validation of a simple thin layer chromatographic method for the analysis of artemisinin in Artemisia annua L. plant extracts.   Biomed Chromatogr, 22(5): 454-9.

Owing to the development of parasite resistance to standard antimalarial treatments like chloroquine and sulfadoxine-pyrimethamine, the demand for Artemisia annua, a key ingredient for new and highly effective antimalarial drugs, is huge. Therefore selective and precise methods to determine the content of artemisinin in dry plant material and in raw impure extracts are needed. In this work a method is described for the clear separation and extraction of artemisinin from other plant components ... [Abstract] [Full-text]

Thermochemical and kinetic study of the carbocation ring contraction of cyclohexylium to methylcyclopentylium.   J Phys Chem A, 112(17): 4004-10.

The isomerization of cyclohexylium to methylcyclopentylium is a model for a key step required in sterol and triterpene biosynthesis and is important in catalytic processes associated with ring-opening reactions in upgrading petroleum fractions. Using high-level, correlated wave function techniques based on QCISD, the mechanism for this isomerization was found to be very different from that first proposed more than 35 years ago. On the basis of our mechanism, a first-order rate constant ... [Abstract] [Full-text]

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