Petroleum Hydrocarbon Profiles of Water and Sediment of Algoa Bay, Eastern Cape, South Africa (original) (raw)
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Petroleum hydrocarbon status of the Buffalo River Estuary in East London, South Africa, was evaluated from January to May, 2016. Surface water and sediment samples were collected from five points in the estuary and extracted using standard methods. The extracts were subsequently analyzed by gas chromatography-flame ionization detection. Results showed that total petroleum hydrocarbon (TPH) varied from 7.65 to 477 í µí¼g/L in the water and 12.59 to 1,100 mg/kg in the sediments, with mean values of 146.50 ± 27.96 í µí¼g/L and 209.81 ± 63.82 mg/kg, respectively. Concentrations of TPH in the sediments correlated significantly with organic carbon (OC) in both seasons. TPH and OC levels were slightly lower in summer than in autumn in the two environmental matrices, and the average amount of TPH in the water samples collected from all the sampling stations was generally lower than the EU standard limit of 300 í µí¼g/L. However, the levels in the sediments exceeded the EGASPIN target value (50 mg/kg) for mineral oil but were below the intervention value (5,000 mg/kg), indicating a serious impact of industrial growth and urbanization on the area, although the n-alkane ratios and indexes used for source tracking revealed excessive flow from both natural and anthropogenic sources.
Quimica Nova, 2009
This work describes a validation of an analytical procedure for the analysis of petroleum hydrocarbons in marine sediment samples. The proposed protocol is able to measure n-alkanes and polycyclic aromatic hydrocarbons (PAH) in samples at concentrations as low as 30 ng/g, with a precision better than 15% for most of analytes. The extraction efficiency of fortified sediments varied from 65.1 to 105.6% and 59.7 to 97.8%, for n-alkanes and PAH in the ranges: C16 - C32 and fluoranthene - benzo(a)pyrene, respectively. The analytical protocol was applied to determine petroleum hydrocarbons in sediments collected from a marine coastal zone.
Marine Chemistry, 1981
Awad, H., 1981. Comparative studies on analytical methods for the assessment of petroleum contamination in the marine environment. II. Gas chromatographic analyses. Mar. Chem., 10: 417-430. Although determinations of hydrocarbons in the marine environment are usually based on the same analytical steps, i.e. organic solvent extraction, column chromatographic purification, and hydrocarbon detection and identification; variations in equipment and solvent systems used in the extraction step, and also in the columns for purification and analysis, seriously impaired the development of a consistent data base concerning oil pollution on a global scale. Many authors and conferences emphasized the need, in this field, for a comparative study on the efficiency of various published analytical techniques. Fifteen techniques with 24 applications were chosen and applied to a fixed weight of uniform samples of sediments, mussels, fish, shrimps and green algae. The final hydrocarbon extracts were analyzed individually on a 2 m stainless-steel packed column (SE 30). The results obtained from this work showed considerable variations in the efficiency of different techniques from identical samples. The hydrocarbon yields varied from 94 to 1.4ppm in sediments, from 40 to 9ppm in mussels; from 216 to 1.3ppm in fish; from 8.3 to 3.1 ppm in shrimps; and from 343 to 273ppm in algae, all relative to wet weight of the samples. The gas chromatograms of the hydrocarbons obtained were found to be quite different with regard to peak intensities and distributions. This means that hydrocarbons obtained by the application of different techniques varied in their compositions and relative concentrations of their constituents. These results confirm what was already obtained and discussed previously using spectrofluorometric analyses. It can be concluded that it is necessary to establish a standard technique for the preparation of marine samples, for extraction and purification of the hydrocarbon extracts which should be applied by all laboratories specializing in this field.
Several methods of extraction and analytical determination for total petroleum hydrocarbons (TPHCs) in aqueous and solid samples are reviewed. Infrared spectroscopy is one of the efficient methods that are being replaced today pursuant to getting rid of some halogenated solvents classified as ozone-depleting substances. The gravimetric method which uses n-hexane as an extraction solvent for the determination of oil and grease, as well as the nonpolar materials, has become a preferred choice, despite being not suitable for volatiles because of the mandatory evaporation step. Other frequently used methods include gas chromatography with a flame ionization detector (FID) or mass spectrometric detector (MSD) which has the capacity to reveal the type of hydrocarbons present and is applicable to both volatile and semivolatile samples. Ultraviolet fluorescence is another method that is available both as a portable field device and as off-site laboratory equipment. Each of the methods has its own advantages and disadvantages; hence, the choice of method is guided by the type of data needed as discussed in detail in this review. The distribution of TPHC in water and sediments across the globe and the factors influencing the distribution were also reviewed.
Several methods of extraction and analytical determination for total petroleum hydrocarbons (TPHCs) in aqueous and solid samples are reviewed. Infrared spectroscopy is one of the efficient methods that are being replaced today pursuant to getting rid of some halogenated solvents classified as ozone-depleting substances. The gravimetric method which uses n-hexane as an extraction solvent for the determination of oil and grease, as well as the nonpolar materials, has become a preferred choice, despite being not suitable for volatiles because of the mandatory evaporation step. Other frequently used methods include gas chromatography with a flame ionization detector (FID) or mass spectrometric detector (MSD) which has the capacity to reveal the type of hydrocarbons present and is applicable to both volatile and semivolatile samples. Ultraviolet fluorescence is another method that is available both as a portable field device and as off-site laboratory equipment. Each of the methods has its own advantages and disadvantages; hence, the choice of method is guided by the type of data needed as discussed in detail in this review. The distribution of TPHC in water and sediments across the globe and the factors influencing the distribution were also reviewed.
Aliphatic and Aromatic Biomarkers for Petroleum Hydrocarbon Investigation in Marine Sediment
Journal of Petroleum Science Research, 2013
Levels, composition profiles and sources of hydrocarbons were analyzed in surface marine sediment samples collected from Khniss Coast in Tunisia. It was found that the total Hydrocarbon (TH) concentrations ranged from 2280 μg/g to 7700 μg/g. The sedimentary non-aromatic hydrocarbon (NAH) and aromatic hydrocarbon (AH) concentrations ranged from 1020 to 2320 μg/g, and from 240 to 680 μg/g, respectively. The level of 17 polycyclic aromatic hydrocarbons (∑17PAHs) is equal to 14.59 ng/g. The PAH profiles showed that the ∑4-5-ring compounds were the major PAHs detected in the sampling sites. Characteristic ratios of Anth/(Anth+ Phe), and Flu/(Flu + Pyr) indicated that PAHs could originate from petrogenic and pyrolytic sources. Petroleum contamination associated with increased marine activity and high eutrophization statue in Khniss area which may have side-effects on the ecosystems and human safety; thus, it must be controlled.
Journal of the Brazilian Chemical Society, 2018
Different clean-up methods to determine isotopic composition of n-alkanes were tested. Sources of organic matter in Guanabara Bay were reexamined through the δ 13 C of individual n-alkanes in surface sediment samples. The n-alkanes were efficiently isolated without significant losses of the compounds of interest. The δ 13 C of n-alkanes (n-C 17 to n-C 35) ranged between-34.0 and-26.4‰. More depleted δ 13 C values associated to higher carbon preference index (CPI > 4) suggest prevalence of biogenic n-alkanes from terrestrial origin in the inner stations influenced by inputs from mangrove areas. Small isotopic differences between odd and even-numbered chains and 13 C-enrichment in long-chain homologues indicate a petrogenic hydrocarbons contribution. Higher concentrations of short-chain compounds associated to a more 13 C-enriched total organic carbon (TOC) were found near the most intense sewage discharges. Results show that δ 13 C of n-alkanes can be applied to a highly degraded system as the Guanabara Bay and help improve the characterization of the organic matter.