scholarly journals Occurrence and sources of aliphatic hydrocarbons in anthropogenic impacted soils from petroleum tank-farms in the Niger Delta, Nigeria

2020 ◽  
Vol 31 (2) ◽  
pp. 132-144
Author(s):  
Onoriode O. Emoyan ◽  
Chiedu C. Ikechukwu ◽  
Godswill O. Tesi
Keyword(s):  
Niger Delta ◽  
Total Concentration ◽  
Carbon Number ◽  
Packed Column ◽  
Aliphatic Hydrocarbons ◽  
Mitigation Measures ◽  
Soil Profiles ◽  
Equivalent Carbon Number ◽  
Priority Pollutants ◽  
Exposure Risks

Abstract The occurrence and compositional pattern of priority pollutants are vital in understanding the anthropogenic contributions, origin, and risks of these pollutants to the surrounding environment. Thus, the focus of this study was to determine the concentrations, compositional profiles, and sources of aliphatic hydrocarbons (AHCs) in anthropogenic impacted soils from petroleum tank-farms environment in the Niger Delta, Nigeria. Forty-five soil samples were collected from the vicinity of petroleum tank-farms at the top (0-15 cm), sub (15-30 cm), and bottom (30-45 cm) soil depths. The concentration of AHCs was determined using gas chromatography-mass spectrometer (GC-MS) after extraction by ultrasonication with hexane/dichloromethane and clean-up in silica gel/alumina packed column. The mean concentrations of AHCs in the samples ranged from 0.52 ± 0.90 to 35.26 ± 35.69 mg/kg. The AHCs results show that the equivalent carbon number index (ECn-) ECn-13-35 had the highest concentration when compared to ECn-8-12 and ECn-36-40. The linear regression and ANOVA indicate that there is no significant positive correlation between TOC and the total concentration of AHCs in the soil profiles, and a significant variation in AHCs levels between soil profiles respectively. Results also showed that soils from the tank-farms are moderately contaminated with AHCs when compared to the UNEP recommended limit. However, when compared to other regulatory thresholds, the observed concentrations of AHCs, human and environmental health risks are likely. Source apportionments depict that the principal sources of AHCs were petrogenic and plant diagenesis. Appropriate clean-up and mitigation measures and further study to determine the occurrence, composition, and exposure risks of other priority pollutants in water and sediment samples from the surrounding creeks should be determined.

scholarly journals Validation of a Method Based on Triglycerides for the Detection of Low Percentages of Hazelnut Oil in Olive Oil by Column Liquid Chromatography

2007 ◽  
Vol 90 (5) ◽  
pp. 1346-1353 ◽  
Author(s):  
Diego L García-González ◽  
María Viera-Macías ◽  
Ramón Aparicio-Ruiz ◽  
Maria T Morales ◽  
Ramón Aparicio
Keyword(s):  
Liquid Chromatography ◽  
Olive Oil ◽  
Carbon Number ◽  
Hazelnut Oil ◽  
Equivalent Carbon Number ◽  
Experimental Conditions ◽  
Mathematical Algorithm ◽  
Relative Standard ◽  
Triglyceride Content ◽  
The Difference

Abstract The difference between theoretical and empirical triglyceride content is a powerful tool to detect the presence of any vegetable oil in olive oil. The current drawback of the method is the separation between equivalent carbon number ECN42 compounds, which affects the reliability of the method and, hence, its cutoff limit. The determination of the triglyceride profile by liquid chromatography using propionitrile as the mobile phase has recently been proposed to improve their quantification, together with a mathematical algorithm whose binary response determines the presence or absence of hazelnut oil. Twenty-one laboratories from 9 countries participated in an interlaboratory study to evaluate the performance characteristics of the whole analytical method. Participants analyzed 12 samples in duplicate, split into 3 intercomparison studies. Statistically significant differences due to the experimental conditions were found in some laboratories, which were detected as outliers by use of Cochran's and Grubbs' tests. The relative standard deviations (RSD) for repeatability and reproducibility were determined following the AOAC Guidelines for Collaborative Studies. The analytical properties of the method were determined by means of the sensitivity (0.86), selectivity (0.94), and reliability (72) for a cutoff limit of 8 (probability 94).

scholarly journals Lipase-catalyzed transesterification of medium-long-medium structured lipid (MLM-SL) using palm olein and tricaprylin in packed-bed reactor (PBR)

2021 ◽  
pp. 909
Author(s):  
Qabul Dinanta Utama ◽  
Azis Boing Sitanggang ◽  
Dede Robiatul Adawiyah ◽  
Purwiyatno Hariyadi
Keyword(s):  
Residence Time ◽  
High Performance ◽  
Palm Olein ◽  
Carbon Number ◽  
Packed Bed ◽  
Structured Lipid ◽  
Packed Bed Reactor ◽  
Equivalent Carbon Number ◽  
Lipozyme Tl Im ◽  
Slip Melting Point

Lipase-catalyzed transesterification between refined bleached deodorized palm olein (RBDO) and tricaprylin to produce medium-long-medium structured lipid (MLM-SL) in a packed bed reactor (PBR) has been investigated. A specific sn-1,3 commercial Lipozyme TL IM was used as biocatalyst.  Within this study, the progress of transesterification was monitored especially for triacylglycerol (TAG) formation with equivalent carbon number (ECN) of 32, presumably 1,3-dicapryoyl-2-oleoyl-sn-glycerol (COC). Transesterification conditions investigated were residence times (i.e., 15, 30, and 60 min) and enzyme loadings (2.0 and 4.5 g).  The highest yield of ECN 32 (13%) and transesterification degree (71%) were obtained at residence time of 15 mins for both enzyme loadings. Longer residence time seemed to facilitate lipid hydrolysis over transesterification. This was indicated by the number of peaks appearing in the high-performance liquid chromatography (HPLC) chromatograms and the reduction of fat slip melting point (SMP). Additionally, the highest productivity was obtained at 2.0 g enzyme loading. Conclusively, this study has demonstrated the potential use of packed-bed reactor with immobilized Lipozyme TL IM for continuous synthesis of MLM-SLs especially TAG with ECN32.

scholarly journals Avian Influenza H5N1: Risks at the Human–Animal Interface

2007 ◽  
Vol 28 (2_suppl2) ◽  
pp. S357-S363 ◽  
Author(s):  
Elizabeth Mumford ◽  
Jennifer Bishop ◽  
Saskia Hendrickx ◽  
Peter Ben Embarek ◽  
Michael Perdue
Keyword(s):  
Avian Influenza ◽  
Human Exposure ◽  
Animal Health ◽  
Epidemiological Data ◽  
World Health ◽  
Mitigation Measures ◽  
Pandemic Virus ◽  
Human Animal ◽  
Exposure Risks ◽  
Health Organization

Background Great concern has arisen over the continued infection of humans with highly pathogenic avian influenza (HPAI) of the H5N1 subtype. Ongoing human exposure potentially increases the risk that a pandemic virus strain will emerge that is easily transmissible among humans. Although the pathogenicity of a pandemic strain cannot be predicted, the high mortality seen in documented H5N1 human infections thus far has raised the level of concern. Objectives To define the three types of influenza that can affect humans, discuss potential exposure risks at the human–animal interface, and suggest ways to reduce exposure and help prevent development of a pandemic virus. Methods This review is based on data and guidelines available from the World Health Organization, the scientific literature, and official governmental reports. Results Epidemiological data on human exposure risk are generally incomplete. Transmission of HPAI to humans is thought to occur through contact with respiratory secretions, feces, contaminated feathers, organs, and blood from live or dead infected birds and possibly from contaminated surfaces. Consumption of properly cooked poultry and eggs is not thought to pose a risk. Use of antiviral containment and vaccination may protect against development of a pandemic. Conclusions To most effectively decrease the risk of a pandemic, the public health and animal health sectors—those which are responsible for protecting and improving the health of humans and animals, respectively—must collaborate to decrease human exposure to HPAI virus, both by controlling virus circulation among poultry and by assessing the risks of human exposure to avian influenza virus at the human—animal interface from primary production through consumption of poultry and poultry products, and implementing risk-based mitigation measures.

scholarly journals n-alkanes from Paepalanthus Mart. species (Eriocaulaceae)

2005 ◽  
Vol 19 (4) ◽  
pp. 727-732 ◽  
Author(s):  
Lourdes Campaner dos Santos ◽  
Anne L. Dokkedal ◽  
Miriam Sannomiya ◽  
Maria Carla Piza Soares ◽  
Wagner Vilegas
Keyword(s):  
High Frequency ◽  
Carbon Number ◽  
Polar Compounds ◽  
Aliphatic Hydrocarbons ◽  
Flavonoid Glycosides ◽  
Taxonomic Character ◽  
Carbon Chains ◽  
Nonpolar Compounds ◽  
Long Chain

This work presents the study of nonpolar compounds from plants belonging to the genus Paepalanthus Mart. (Eriocaulaceae). Long-chain linear aliphatic hydrocarbons were identified by GC-FID and GC-MS. The results indicate that Paepalanthus subg. Platycaulon species present a very homogenous profile, with carbon chains of n-alkanes ranging from C25 to C31, most samples presenting higher frequencies of C27 and C29 homologues. Paepalanthus subg. Paepalocephalus species may be distinguished from one another by the distribution of main n-alkanes. P. macrocephalus, subsect. Aphorocaulon species, presents alkanes with odd-carbon numbers and P. denudatus and P. polyanthus, Actinocephalus species, present alkanes with quite distinctive profiles, with many shorter chains and a high frequency of even-carbon number, especially P. polyanthus. The results obtained indicate that the distribution of alkanes can be a useful taxonomic character, as do polar compounds like flavonoid glycosides.

Gasoline and Kerosene Components in Blood - A Forensic Analysis

1988 ◽  
Vol 7 (4) ◽  
pp. 299-305 ◽  
Author(s):  
K. Kimura ◽  
T. Nagata ◽  
K. Hara ◽  
M. Kageura
Keyword(s):  
Solvent Extraction ◽  
Carbon Number ◽  
Extraction Methods ◽  
Forensic Analysis ◽  
Aliphatic Hydrocarbons ◽  
Laboratory Animals ◽  
Gas Chromatography Mass Spectrometry ◽  
Head Space ◽  
Solvent Extraction Method ◽  
Simultaneous Procedures

A reliable method to analyse small amounts of fuel components in biological materials, using two simultaneous procedures, head space and solvent extraction methods has been developed. Gas chromatography/mass spectrometry (GC/MS) was used for qualitative and quantitative determinations. The aliphatic hydrocarbons with carbon numbers of 5 to 8 and aromatics such as benzene, toluene and xylenes were detected in laboratory animals, following exposure to gasoline vapour, using the head space method. Aliphatic hydrocarbons with carbon numbers over 9 as well as the aromatics with carbon number 9 group including cumene, mesitylene, pseudocumene and 1,2,3-trimethylbenzene were determined by the solvent extraction method following exposure to kerosene vapour. The lower limits of detection were 0.01 μg and 50 pg in gasoline and kerosene components, respectively. The methods were found to be applicable in confirming the cause of human deaths.

Spatial Emission Characteristics of a Capillary-Burner Excitation Source for a Flame Infrared Emission (FIRE) Radiometer

1991 ◽  
Vol 45 (10) ◽  
pp. 1684-1694 ◽  
Author(s):  
S. Ravishankar ◽  
David C. Tilotta ◽  
Kenneth W. Busch ◽  
Marianna A. Busch
Keyword(s):  
Carbon Dioxide ◽  
Carbon Number ◽  
Vertical Axis ◽  
Infrared Emission ◽  
Aliphatic Hydrocarbons ◽  
Number Density ◽  
Particulate Carbon ◽  
Complete Mapping ◽  
Diffusion Controlled ◽  
Radial Profiles

A complete mapping of the lateral and radial intensities of the 4.4- μm emission (antisymmetric CO2 stretch) resulting from the direct introduction of carbon dioxide, a homologous series of aliphatic hydrocarbons, and benzene into a hydrogen/air combustion flame supported on a capillary burner has been carried out. Both concentrated (99% methane, ethane, propane, and butane) and dilute (1% methane, ethane, propane, and benzene) hydrocarbons were studied. Flame profiles produced by the introduction of carbon dioxide were used to indicate the effects of local variations in source temperature and carbon dioxide number density in the absence of combustion. The radial profiles produced by the introduction of carbon dioxide and the hydrocarbons revealed a considerable amount of off-axis emission, believed to result from a zone of low temperature along the central vertical axis of the burner. Combustion of analyte appeared to be a diffusion-controlled process. For aliphatic hydrocarbons, combustion produced nearly quantitative amounts of carbon dioxide, provided the flame was not overloaded. For benzene, combustion produced particulate carbon, and the resulting blackbody emission was not strictly related to analyte concentration or carbon number. Blackbody emission may also result from the incomplete combustion of longer chain aliphatic hydrocarbons (propane and butane), if the burner is overloaded.

scholarly journals Leaching and transport of Zn through soil profiles in a seasonal river of a mining area in SE Spain

2013 ◽  
Vol 9 (3) ◽  
pp. 214-223
Keyword(s):  
Total Concentration ◽  
Mediterranean Area ◽  
Mining Area ◽  
Soil Profiles ◽  
Se Spain ◽  
River Bed ◽  
River Stretch ◽  
Soils And Sediments ◽  
Short And Long Term ◽  
Metal Flux

Metal pollution can have adverse effects on human health but also on environment. Usually, risk is assessed on the basis of the total concentration of a trace metal in soils and sediments. Nevertheless, for checking the short and long-term true environmental impact of a trace element, one of the most crucial factors to consider is its mobility. Leachability of metals from soils and sediments and, thus, their mobility, depends on several factors such as the soil type on the basis of the parameters that affect metal interaction, the nature of the pollution in terms of the deposition and composition, and finally the environmental conditions that may lead to weathering. This study has been focused on the metal behaviour in some soil and sediment profiles placed in the river-bed of a seasonal river from a semiarid mining Mediterranean area, in SE Spain. Data from these analyses showed that a change of the environment conditions could remobilise great amounts of Zn. In this sense, a change of acidic conditions could affect mainly to the lower drill. Meanwhile a change of reducing or oxidizing conditions can affect to middle and upper drills zinc remobilization. Middle stretch of the seasonal river shows a very different behaviour in relation to zinc mobility, leachibility and distribution in soil profiles. For this river stretch, metal accumulation in the soil profile is higher, and leachibility risks for groundwater could be higher. Besides, the lower stretch of the seasonal river show a special metal distribution because of the underlying materials are placed in the saturated zone (marine aquifer), what can determinate a horizontal, more than a vertical, metal flux.

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