Validation of an analytical methodology for the quantitative analysis of petroleum hydrocarbons in marine sediment samples (original) (raw)
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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, 2012
The main steps involved in the determination of aliphatic and aromatic hydrocarbons in sediments were evaluated in this work. In the extraction, factors such as the cooling system, time and solvent were evaluated. During the extraction and concentration, steps aspects such as time, extraction solvent and cooling system were evaluated. In the cleanup different solvents and elution mixtures were studied. The results were considered satisfactory (70-120%). Linearity and limits of detection and quantification were studied by means of calibration curves (R > 0.90) and the results demonstrated high sensitivity of the method. Precision and accuracy were studied by recovery tests using a certified reference material and sodium sulfate. In recovery tests, the standard deviations were below 20%, with percent recoveries for aliphatic and aromatics ranging from 59 to 105% and 55 to 113%, respectively. For the reference sediment, the standard deviations were lower than the certified values, with satisfactory recovery values. The present work provided a way of improving an already established method with high analytical reliability.
Biological Mass Spectrometry, 1987
The establishment of reliable values for concentrations of 16 priority pollutant polycyclic aromatic hydrocarbons (PAH) in a suite of marine sediment reference materials included an examination of the methods used to determine such compounds. Results from the five techniques used indicate large method biases. The biases arise from chemical interferences in methods which use non-selective measuring systems with separation techniques which do not first completely resolve the analytes; e.g., single-parameter optical detectors with high performance liquid chromatographic (HPLC) techniques or a flame ionisation detector (FID) with capillary column gas chromatographic (GC) methods. Measurement by a mass spectrometer with HPLC and GC removes much of the method bias. Results for a representative sediment are discussed to illustrate these conclusions.
Molekul, 2016
As maritime fulcrum nation, in Indonesia, marine environmental analytical chemistry field is still under developed. So that why, this review paper aims to provide basic understanding of the use some molecular diagnostic indices using n-alkanes indexes and polycyclic aromatic hydrocarbons (PAHs) diagnostic ratios to estimate the source of apportionment of the hydrocarbons contamination and origin. The n-alkane chromatograms were then used to characterize the predominance of petrogenic or biogenic either terrestrial or aquatic. Furthermore, characterization allowed to discriminate riverine versus marine input. The occurrence of a broad unresolved complex mixture can be an evidence of biodegraded petroleum residues. For aromatic compounds, the prevalence of petrogenic, pyrolitic, and combustion-derived can be easily plotted by using isomers ratio calculation. This paper thus provides useful information on the hydrocarbon contamination origin, especially in marine sediments. Further res...
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.
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.
Characteristics of Naturally Occurring and Pollutant Hydrocarbons in Marine Sediments
Proceedings, 1973
Hydrocarbons spilled on the sea may, naturally or by sinking agent, settle on the sea bed and pollute marine muds which are the substratum of the benthic fauna and flora. They may be absorbed by these organisms which are the basis of the nutrition for a large part of the aquatic fauna. This hydrocarbon pollutants will enter by this way in the marine food chain and raise the problem of long term toxicity. Therefore it is important to measure the quantity of hydrocarbons in the marine sediments in order to know the level of pollution. We must, however, be able to make the difference between indigenous hydrocarbons and crude-oil derived hydrocarbons. Both contain, n and isoalkanes, cyclo-alkanes and aromatics, but their quantity, the percentage of each type of compounds and the distribution of some specific molecules are often very particular. A detailed analysis of the chloroform extract of the sediment by chromatography, mass spectrometry and U. V. fluorescence can discriminate between unpolluted and polluted sediments even in the case of low level pollution. The samples which have been analysed, were collected on the French coast of the English channel in Normandie and in the Seine Bay. It has been noted in the unpolluted samples a higher percentage of heavy products (resins and asphaltenes), a more important odd carbon dominance in the n-alkanes distribution than in the polluted ones. The aromatic fraction of the indigenous hydrocarbons is mainly composed of polycyclic aromatic hydrocarbons without alkyl chains whereas polluted samples show many types of alkylaromatics.