Aliphatic hydrocarbons sediments

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). 

Grathwohl P (1990) Influence of organic-matter from soils and sediments from various origins on the some chlorinated aliphatic-hydrocarbons - implications on Koc correlations. Environ Sci Technol 24 1687-1693... 

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. 

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. 

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. 

Fig. 2 a - c. GC-MS traces (m/z 99 key ion) of various aliphatic hydrocarbon fractions from different environmental matrices a sediment - Red Sea b water - Red Sea c Kuwait crude oil spill... 

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. 

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. 

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],... 

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. 

The aliphatic hydrocarbon distribution (Figure 6) of a sediment from the Cariaco Trench (DSDP 15-147C-3-3) off Venezuela contains two structural families of diagnostic compounds in addition to the steroids and triterpenoids in the polycyclic region. 

Bound aliphatic hydrocarbons comprised 7 of the saponifiable lipid (<1 to 15 ug/g). Unbound/bound ratios of <1 to 67 of this hydrocarbon fraction, with the exception of 603B-29-1, agree with values reported in other studies (, 37). Bound alkane distributions were dominated by C or C-, (Figure 3). Even-carbon predominance of alkanes is an anomaly, but distributions similar to those in the present study have been observed in other North Atlantic deep-sea sediments ( 29). The source of these compounds, however, is unknown. 

Considerable attention has been directed to particulate organic matter (POM) in the marine environment that is plausibly derived from organisms in the euphotic zone. This is supported by MS comparison of pyrolysis products from samples collected in sediment traps in the Mediterranean Sea with that from the diatom Biddulphia sinensis. Although the structures are unknown, a wide variety of compounds have been identified in the pyrolysates including aliphatic hydrocarbons and nitriles, pyrroles, indoles, and aromatic hydrocarbons (Peulve et al. 1996). 

Numerous studies have shown that lower aliphatic hydrocarbons containing up to at least 20 carbon atoms (molecular weights below 300 daltons) can be assimilated by a wide variety of microorganisms, including twenty or so different types of bacteria and 150 or so different types of yeasts, which are found in soil and marine sediments. In aqueous media, some of these microorganisms secrete surfactants to facilitate contact and the utilization of the hydrocarbon substrates. 

Sixth, there appears to be no general correlation between the distribution and concentration of PAHs and the various aliphatic hydrocarbon ratios and parameters generally used to indicate petroleum contamination of samples. These ratios may be used in detecting relatively gross levels of petroleum contamination however, they are of little value in determining trace petroleum hydrocarbon contamination in sediment samples. 

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