Aliphatic hydrocarbons in sediment

Zhao H., Chen J., Quan X., Yang F., and Peijnenburg W. J. G. M. (2(X)1) Quantitative structure-property relationship study on reductive dehalogenation of selected halogenated aliphatic hydrocarbons in sediment slurries. Chemosphere 44, 1557-1563. 

Figure 6. Concentrations of total extractable aliphatic hydrocarbons in sediment cores from Lake Washington in urban Seattle and Lake Quinault in rural Washington. Gas chromatographic traces illustrate hydrocarbon distributions in three of these core samples. Carbon numbers of/i-alkanes are indicated on the traces UCM represents the unresolved complex mixture of hydrocarbons underlying the individual aliphatic hydrocarbon peaks. Most of the increase in Lake Washington hydrocarbon concentrations since ca. 1900 is due to the large addition of petroleum residues, indicated by the UCM, to a low background of land plant n-alkanes, typified by the Lake Quinalt hydrocarbon contents. Core sediment ages shown are from - "Pb dating. Adapted from Wakeham (1976).

There are fewer data available to assess the residual concentrations of the 27 organic solvents in soil and sediment samples (Table 16.1.5). Although an effort was made to exclude data from point sources such as industrial sites or chemical spills, the influence of point sources cannot be ignored. Although some of solvents have been detected at trace levels, the median concentration of the chlorinated aliphatic hydrocarbons in sediments has often been less than the analytical ability to measure them accurately. 

Page et al. [21] used capillary gas chromatography and capillary gas chromatography-mass spectrometry to determine aliphatic hydrocarbons in interstitial sediments collected on the French coastline following the Amoco Cadiz disaster. 

Serrano, A. and M. Gallego. 2006. Continuous microwave-assisted extraction coupled on-line with liquid-liquid extraction Determination of aliphatic hydrocarbons in soil and sediments. J. Chromatogr. A 1104 323-330. 

Polyalphaolefin Hydraulic Fluids. As is the case with mineral oil hydraulic fluids, it may be difficult to assess the presence of polyalphaolefin hydraulic fluids in sediments and soil by identifying occurrences of the components of these hydraulic fluids, because the aliphatic hydrocarbon isomers in polyalphaolefin hydraulic fluids also are present in mineral oils. Thus, the occurrence of polyalphaolefins in sediments and soil cannot always be uniquely associated with hydraulic fluid usage. 

Mineral Oil Hydraulic Fluids. Methods are available for analysis of the hydrocarbon components of mineral oil hydraulic fluids (predominantly straight and branched chain alkanes) in environmental samples. Some of these methods are summarized in Table 6-3. In general, water and sediment samples are extracted with a suitable solvent in a Soxhlet extractor (for solid samples) or in separatory funnel or shake flask (for liquid samples) (Bates et al. 1984 Peterman et al. 1980). The extract is cleaned up on silica gel or Florisil columns using a nonpolar solvent to elute the nonpolar alkanes. Analysis is usually performed by GC/MS (Bates et al. 1984 Kawamura and Kaplan 1983 Peterman et al. 1980). Method performance has not been reported, although 82% recovery of aliphatic hydrocarbons was reported for rainwater (Kawamura and Kaplan 1983). 

Spectrofluorimetric methods are applicable to the determination of aliphatic hydrocarbons, and humic and fulvic acids in soil, aliphatic hydrocarbons polyaromatic hydrocarbons, optical whiteners, and selenium in non-saline sediments, aliphatic aromatic and polyaromatic hydrocarbons and humic and fulvic acids in saline sediments. The only application found in luminescence spectroscopy is the determination of polychlorobiphenyl in soil. Generally speaking, concentrations down to the picogram (pg L 1), level can be determined by this technique with recovery efficiencies near f00%. 

Infrared spectroscopy has been applied to the determination of particulate organic carbon in non-saline sediments, aliphatic hydrocarbons and total organic carbon in saline sediments and mixtures of organics in sludges. 

Aliphatic hydrocarbons, triazine, substituted urea type and phenoxyacetic acid types of herbicides, Fluazifop and Fluazifop-butyl herbicides, ethylene diamine tetracetic acid salts in soil, aliphatic and polyaromatic hydrocarbons, phthalate esters, various organosulphur compounds, triazine herbicides, optical whiteners, mixtures of organic compounds and organotin compounds in non-saline sediments, aromatic hydrocarbons, humic and fulvic acids and mixtures of organic compounds in saline sediments and non-ionic surfactants and cobalamin in sludges. 

Despite the advances made in high-performance liquid chromatography in recent years, there are still occasionally applications in which conventional column chromatography is employed. These methods lack the sensitivity, resolution and automation of HPLC. They include the determination of urea herbicides in soil, polyaromatic hydrocarbons, carbohydrates, chloroaliphatic compounds and humic and fulvic acids in non-saline sediments. The technique has also been applied in sludge analysis, e.g. aliphatic hydrocarbons and carboxylic acids. 

Interlocutory, comparisons have been performed on the determination of selected trace aliphatic and aromatic hydrocarbons in marine sediments [25-27],... 

Whittle [29] has described a thin-layer chromatographic method for the identification of hydrocarbon marker dyes in oil polluted waters. McLeod et al. [25] conducted interlaboratory comparisons of methods for determining traces of aliphatic and aromatic hydrocarbons in marine sediments. Agreement within a factor of 2 to 3 was obtained between the 12 participating laboratories. 

The flash evaporation pyrolysis gas chromatography method [16] as described in section 11.1.4 for the determination of polycyclic aromatic hydrocarbons, haloorganics, aliphatic hydrocarbons, heteroaromatics, elemental sulphur and pyrolysis products of synthetic polymers in soils has also been applied to non-saline sediments. 

Grant, B.F. Endrin toxicity and distribution in freshwater a review. Bull Environ. Contam. Toxicol, 15 (3) 283-290, 1976. Grathwohl, P. Influence of organic matter from soils and sediments from various origins on the sorption of some chlorinated aliphatic hydrocarbons implications on Koc correlations. Environ. Sci. Technol, 24(11) 1687-1693, 1990. 

Addition of fuel oil no. 2 to a laboratory marine ecosystem showed that the insoluble, saturated hydrocarbons in the oil were slowly transported to the sediment on suspended particulate material. The particulate material contained 40-50% of the total amount of aliphatics added to the system and only 3-21% of the aromatic fraction (Oviatt et al. 1982). This indicates that most aromatic hydrocarbons are dissolved in the water (Coleman et al. 1984), whereas the aliphatic hydrocarbons are not (Gearing et al. 1980 Oviatt et al. 1982). In a similar experiment, when fuel oil no. 2 was added continuously to a marine ecosystem for 24 weeks, oil concentrations in the sediment remained low until 135 days after the additions began, but then increased dramatically to levels that were 9% of the total fuel oil added (108 g/tank) and 12% of the total fuel oil saturated hydrocarbons. The fuel oil concentrations in the sediment began to decrease quite rapidly after the maximum levels were reached. The highest sediment concentrations of saturated hydrocarbons (106-527 g/g) were found in the surface flocculent layer, with concentrations decreasing with sediment depth from 22 g/g to not detectable at 2-3 cm below the sediment surface. 

Many microwave extractions can reach maximum recovery in 10 to 20 minutes. Longer extraction time is not necessary and may lead to the decomposition of thermolabile analytes. It was reported that the recovery of sulfonylurea from soil was not affected by extraction time in the range 5 to 30 minutes [79], Similar observation was made in the extraction of PAHs from soils and sediments [6], In the extraction of PAHs and LAHs (linear aliphatic hydrocarbons) from marine sediments, the extraction time was found to be dependent on the irradiation power and the number of samples extracted per run [81], When the irradiation power was 500 W, the extraction time varied from 6 minutes for one sample to 18 minutes for eight samples [74], The recovery of OCPs from spiked marine sediments increased from 30% at 5 and 10 minutes to 60% at 20 minutes and to 74 to 99% at 30 minutes [82],... 

Figure 16 Distribution of total hydrocarbons (total aliphatic and aromatic) in sediments from the Caspian Sea ( x,g g dry wt)...

H. M. Platt, P. R. Mackie, Analysis of aliphatic and aromatic hydrocarbons in Antarctic marine sediment layers, Nature, 280 (1979), 576-578. 

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