Determination of hydrocarbons

Hydrocarbons were identified as marker substances in the 1960s and early 1970s. Pioneer work was done by Kavalam and Nawar (1969) and by Champagne and Nawar (1969) who intensively investigated volatile components. Nawar (1986) reported the occurrence and quantitative distribution of hydrocarbons in irradiated poultry and meat. Some examples of concentrations of hydrocarbons are given in Table 7.4. A strong correlation between dose and hydrocarbon concentration can be observed. This effect can be used to estimate the applied dose. 

Sample preparation. Determination of hydrocarbons can be done only after extraction and enrichment, and a number of different techniques have been developed for this purpose. The lipid can be extracted with organic solvents, for example hexane or pentane, from the matrix. Since 

A characteristic chromatogram from chicken meat irradiated with a 5 kGy dose at a dose rate of 0.9 kGy h is shown in Fig. 7.1. The chromatogram indicates that as well as the characteristic hydrocarbons (1-tetradecene, pentadecane, 1,7-hexadecadiene, 1-heptadecene and 1,8-heptadecene) many non-characteristic volatile compounds have been isolated and detected, which demonstrates the necessity of blank experiments. 

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Data gathering in the water column should not be overlooked at the appraisal stage of the field life. Assessing the size and flow properties of the aquifer are essential in predicting the pressure support which may be provided. Sampling of the formation water is necessary to assess the salinity of the water for use in the determination of hydrocarbon saturations. 

The determination of hydrocarbons is not often required, but is a matter of some importance in the case of the so-called terpeneless and sesquiterpeneless oils, especially those of lemon, many commercial samples of which contain appreciable quantities of hydrocarbons. 

Schantz, M.M., Martire, D.E. (1987) Determination of hydrocarbon-water partition coefficients from chromatographic data and based on solution thermodynamics and theory. J. Chromatogr. 391, 35-51. 

Solvent extraction has proved to be most useful when applied to the concentration of particular compounds for which there exists an analytical method of great sensitivity. The major application of the method has been for the determination of hydrocarbons in seawater. 

Wasik SP, Brown RL (1973) Determination of hydrocarbon solubility in seawater and the analysis of hydrocarbons in water-extracts. In Proceedings of the conference on prevention and control of oil spills. American Petroleum Institute, Washington, DC, pp 223-237... 

Eriksson M, Faldt J, Dalhammar G, Borg-Karlson A-K. Determination of hydrocarbons in old creosote contaminated soil using headspace solid phase microextraction and GC-MS. Chemosphere 2001 44 71641-71648. 

Commonly used methods for the determination of petroleum hydrocarbon contamination in soil are modifications of Environmental Protection Agency method 418.1, which use sonication or a Soxhlet apparatus for analyte extraction and either infrared spectrometry [5] or gas chromatography with flame ionization detection [6-7] for extract analysis. Regardless of the analytical method following the extraction, both modifications use Freon-113, which has been implicated as a cause of ozone depletion. Therefore, alternative methods are being sought for the determination of hydrocarbon contamination in environmental samples that reduce the need for this halogenated solvent. 

Hall, R., Blake, S. B., and Champlin, S. C., Jr., 1984, Determination of Hydrocarbon Thickness in Sediments Using Borehole Data In Proceedings of the National Water Well Association of Ground Water Scientists and Engineers, Fourth National Symposium on Aquifer Restoration and Groundwater Monitoring, p. 300-304. 

Huntley, D., 2000, Analytic Determination of Hydrocarbon Transmissivity from Baildown Tests GroundWater, Vol. 38, No. 1, pp. 46-52. 

Determination of hydrocarbon groups in rubber extender oils by clay-gel adsorption (ASTM D2007)... 

Determination of hydrocarbon types in liquid penoleum products by a fluorescent indicator adsorption test (ASTM D1319)... 

The determination of hydrocarbon contaminants in soil is one of the most frequently performed analyses in the study of contaminated sites and is also one of the least standardized. Given the wide variety of hydrocarbon contaminants that can potentially enter and exist in the soil environment, a need exists for methods that quantify these chemicals satisfactorily. Formerly, the idea of total hydrocarbon determination in soil was seen as providing a satisfactory tool for assessing contaminated sites, but the nature of the method and the site specificity dictate a risk-based approach in data assessment. Quantitation of particular hydrocarbon species may be required. 

Roussis, S. Exhaustive Determination of Hydrocarbon Compound Type Distributions by High Resolution Mass Spec-... 

Farkas, E.J. New method for determination of hydrocarbon-in-water solubilities. Anal. Chem., 37(9) 1173-1175, 1965. 

V. Bansal, G.J. Krishna, A.P. Singh, A.K. Gupta, and A.S. Sarpal, Determination of hydrocarbons types and oxygenates in motor gasoline A comparative smdy by different analytical techniques. Energy Fuels, 22, 410-415... 

Boylan DB, Tripp BW. 1971. Determination of hydrocarbons in seawater extracts of crade oil and crude oil fractions. Nature 230(5288) 44-47. 

Rodriguez OM, Desideri PG, Lepri L, et al. 1991. Simultaneous separation and determination of hydrocarbons and organochlorine compounds by using a two-step microcolumn. J Chromatogr 555 221-228. 

An Infrared Analysis Method for the Determination of Hydrocarbons Collected on Charcoal Tubes... 

Regardless of the analytical method used following the extraction, both modifications use Freon-113, which has been implicated as a cause of ozone depletion. Therefore, alternative methods are being sought for the determination of hydrocarbon contamination in environmental samples that reduce the need for this halogenated solvent. 

Morel et al. [22] compared several methods for the determination of hydrocarbons in soil and found that molecular spectrofluorimety in a Shpoliskii matrix was rapid, accurate and could be automated. 

Thermoanalysis methods such as pyrolysis-gas chromatography-mass spectrometry [GC-MS] and thermogravimetry mass spectrometry have been used to characterise hydrocarbon sludges from petrochemical plants and polluted soils [26,27]. In combination with conventional extraction and supercritical fluid extraction followed by [ GC-MS ], over 100 constituents were identified in samples. White et al. [28] also applied pyrolysis-[GC-MS] to the determination of hydrocarbons and showed that the analysis can be complicated by the presence of natural organic matter. White [28] inferred the presence of biogenic compounds in Alaskan soil. 

A reliable determination of hydrocarbon fluxes is a vital task since the introduction of carbon as a PFC in fusion plasma devices. However, what looked promising after the work of [16,28] has turned out to be a real nightmare in plasma-wall interaction research. A taste of that is seen in Fig. 6.7 where the dependence of chemical erosion yields evaluated in different devices on ion flux density is plotted using the published D/XB-values for CD. Even stronger discrepancies from the general trend have been reported in [29,30]. 

Campbell, R.M., Djordjevic, N.M., Markides, K.E., and Lee, M.L. 1988. Supercritical fluid chromatographic determination of hydrocarbon groups in gasolines and middle distillate fuels. Analytical Chemistry, 60 356-62. 

Figure 1. Separation scheme for the determination of hydrocarbon types in shale oils...

Some specific class analyses have been reported for whole samples and distillates of shale oil and synthetic coal liquids (e.g.. References 1, 2, 3, and 4). A few examples of specific class analyses recently reported include determination of hydrocarbon types in shale oil distillates by a hydroboration technique (5), aromatic-aliphatic group analyses in petroleum and coal liquids (6), nitrogen base types in high-boiling petroleum distillates (7), and PAH fractions in oils (8,9). 

One of the key applications of SFE-FTIR is the extraction and on-line determination of hydrocarbons. Worth special note in this context are the determinations of n-tetra-cosane in Celite (limit of deteetion 74 ng) [126] and petroleum hydrocarbons (TPH) in soils (limit of detection 1.6 ppm), as well as the characterization of edible oils in foods by correlation of the fat vinylic C-H band intensity with the iodine number [108]. 

Determination of hydrocarbons in water -interlaboratory method validation before routine monitoring... 

Abstract The clarification of hydrocarbon input into the Baltic sea via rivers is one of the priority issues of the 4th Pollution Load Compilation (PLC-4) within the framework of international Baltic Sea marine monitoring. An interlaboratory comparison was conducted to check the applicability of a new method for the determination of hydrocarbons by solvent extraction and gas chromatography. Surrogate oil solutions with known hydrocarbon content were distributed among the participants for preparation of water samples of different hydrocarbon con-... 

Within the framework of the 4th Pollution Load Compilation (PLC-4) of Baltic Sea monitoring, the clarification of oil inputs to the Baltic Sea via rivers is one of the priority issues according to Helsinki Commission (HELCOM) recommendations [1], Hence, the determination of hydrocarbons in some larger rivers and point sources is mandatory in PLC-4. Gas chromatographic (GC) determination of hydrocarbons after solvent extraction was chosen as the analytical procedure [2], The method enables the determination of hydrocarbons at concentrations above 0.1 mg L and encompasses a... 

Oil inputs are to be measured within PLC-4 for the first time. To support external quality assurance measures and to obtain information on the proficiency of the nominated laboratories, an interlaboratory comparison on the determination of hydrocarbons in water was conducted before the start of routine monitoring. 

Table 1 Solutions for preparing surrogate samples distributed in the interlaboratory comparison on the determination of hydrocarbons in water...

There were no significant differences between the repeatability or the reproducibility obtained for the standard solution and those obtained for the different water samples. Thus the variability of the sample preparation steps did not seem to contribute markedly to the overall uncertainty of the analytical procedure. It could be concluded that variability in the determination of hydrocarbons in water is mainly a result of the precision of the GC determination. 

Analysis of systematic errors in the determination of hydrocarbons in water can be achieved by use of Youden plots after transformation of the results to an overall mean of Mtotal=0 and a standard deviation of Stotal=l (Fig. 3). Almost all laboratories are distributed around the 45° line indicating that most of the variation was systematic rather than random, particularly at higher mineral oil concentrations (sample pair S2/S4, Fig. 3B). Results located within the interval Mtotal 2 Stotal indicate sufficient proficiency of the participating laboratories in performing the determination of hydrocarbons in water... 

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