Aromatic hydrocarbons fractionation

Grimmer, G., H. Brune, R. Deutsch-Wenzel, G. Dettbam, J. Misfeld, U. Able, and J. Timm. 1985. The contribution of polycyclic aromatic hydrocarbon fractions with different boiling ranges to the carcinogenic impact of emission condensate from coal fired residential furnaces as evaluated by topical application to the skin of mice. Cancer Lett. 28 203-211. 

The transport and dispersion of fuel oils are dependent on the water solubility and volatility of the aliphatic and aromatic hydrocarbon fractions. Lower molecular weight hydrocarbons such as -alkanes may volatilize relatively quickly from both water and soil, while larger aliphatics (greater than C, chain length) may be sorbed to organic particles in water or soil. Aromatic hydrocarbons will be dissolved in the aqueous phase in both soil and water and may undergo some volatilization. 

EPA Toxic Substances Control Act Manufacturers and processors of the C, aromatic hydrocarbon fraction must test this fraction for the following neurotoxicity, mutagenicity, developmental toxicity, reproductive effects, and oncogenicity Yes EPA 1991a (40 CFR 799.2175) EPA 1987c... 

EPA. 1991a. Cg aromatic hydrocarbon fraction. Washington, DC Agency. Code of Federal Regulations. 40 CFR 799.2175. 

De Flora, S., M. Bagnasco, A. Izzotti, F. d Agostini, M. Pala, and F. Valerio, Mutagenicity of Polycyclic Aromatic Hydrocarbon Fractions Extracted from Urban Air Particulates, Mutat. Res., 224, 305-318 (1989). 

There was a small amount of sulfur in the mononuclear aromatic hydrocarbon fractions, which did not show any appreciable resolution on the microcoulometric trace obtained during simulated distillation. According to the U.S. Bureau of Mines report (3) describing this type separation, thiophenes and cyclic sufides could be expected in this fraction. 

In some cases the presence of sulfur in certain constituents of the aromatic hydrocarbon fractions was confirmed by GC with a sulfur-specific detector (FPD) for conditions see (13). 

The "aromatic hydrocarbon" fractions of the laminite sediments from the Nordlinger Ries mainly contain OSC (thiophenes, thiolanes and unidentified... 

Figures 4a—c. Capillary column gas chromatograms of the aromatic hydrocarbon fraction of selected samples from the Nordlinger Ries. M+ = molecular ion, BP = base peak in the corresponding mass spectra. The sample from 151.5 m of well NR-10 contains steroid olefins due to incomplete liquid chromatography separation.

Gas chromatography - mass spectrometry data of the "aromatic hydrocarbon" fractions of nearly 100 Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) sediment samples have been re-examined for the occurrence of organic sulfur compounds (OSC). Approximately 70% of the samples contain OSC with varying distribution patterns, although isoprenoid thiophenes are invariably present. 

Table II. Relative abundance of the major OSC In the "aromatic hydrocarbon" fraction of DSDP/ODP sediment extracts...

Figure 2. Partial reconstructed ion chromatograms of the "aromatic hydrocarbon" fraction of three samples. Numbers refer to Figure 3.

The occurrence of a C20 isoprenoid thiolane, 3-methyl-2-(3,7,11-trimethyldodecyl)thiolane (4), is more restricted (Table II), but it is the most important compound of the "aromatic hydrocarbon" fraction of several Mesozoic black shales from the Falkland Plateau (e.g., late Jurassic sample El 1381 from Site 511 Figure 2). In these samples, additional isoprenoid thiolanes with a base peak at m/z 115 occur in great abundance. Thiolanes have tentatively been suggested as intermediates in the formation of the corresponding thiophenes (24). This is in contradiction to the observation of abundant isoprenoid thiolanes in samples which have experienced more thermal stress and thus are... 

With the demonstration of supercritical fluid extraction, an obvious extension would be to extract or dissolve the compounds of interest into the supercritical fluid before analysis with SFC.(6) This would be analogous to the case in HPLC, where the mobile phase solvent is commonly used for dissolving the sample. The work described here will employ a system capable of extracting materials with a supercritical fluid and introducing a known volume of this extract onto the column for analysis via SFC. Detection of the separated materials will be by on-line UV spectroscopy and infrared spectrometry. The optimized SFE/SFC system has been used to study selected nonvolatile coal-derived products. The work reported here involved the aliphatic and aromatic hydrocarbon fractions from this residuum material. Residua at several times were taken from the reactor and examined which provided some insight into the effects of catalyst decay on the products produced in a pilot plant operation. 

Separation Procedure. The petroleum asphaltenes were separated into five fractions acids, bases, neutral nitrogen compounds, saturate hydrocarbons, and aromatic hydrocarbons. Acids were isolated using anion-exchange resin, bases with cation-exchange resin, and neutral nitrogen compounds by complexation with ferric chloride adsorbed on Attapulgus clay. The remaining hydrocarbon fraction is separated on silica gel to produce saturate and aromatic hydrocarbon fractions. 

Neutral nitrogen fraction Saturate hydrocarbon fraction Aromatic hydrocarbon fraction Total recovery... 

The neutral nitrogen fraction is 1% of the total asphaltene, and the saturate hydrocarbon and aromatic hydrocarbon fractions are 3% and 2%, respectively. The recovery of material after the separation amounted to 99% of the total asphaltene. 

Resing, H. A., Garroway, A. N., and Hazlett, R. N. (1978). Determination of aromatic hydrocarbon fraction in oil shale by C NMR with magic angle spinning. Fuel 57, 450-454. 

The isoprenoid thiophene compound shown in Figure 16 has been observed in other sediments also (48). Inspection of the so called aromatic hydrocarbon fraction of the marl sample with GC-FID, GC-FPD and GC-MS revealed the abundant presence of this compound. Moreover, this fraction is composed, for the most part, of organic sulphur compounds, as can be judged from the GC-trace shown in Figure 18. Other isoprenoid thiophenes, short chain and long chain benzo-... 

Table III. Gravimetric and gas chromatographic data on unbound and non-aromatic hydrocarbon fractions, DSDP Site 603B lower continental rise, U.S, east coast.

Although much information can be obtained from GC-FID, one of the most diagnostic characteristics of a petroleum sample is the molecular nature of the aromatic hydrocarbon fraction idilch can only be determined by GC-MS (6,18,24,32). The reason for this is that in addition to the many PNA parent compounds, there also exist C. C alkylated homology series for each parent PNA. In addition, each or these alkylated homologs can be present as a number of different isomers for each parent structure. 

Fig. 5.60 Oil correlation and source-related plot based on 513C values for saturated and aromatic hydrocarbon fractions (after Sofer 1984).

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