Aromatic hydrocarbons, comparison

Table 2.3 HOMO-LUMO Excitation Energies of Condensed Aromatic Hydrocarbons. Comparison of Values (in cm ) Calculated from the PMO Model with Experimental Data for the L Band (Adapted from Heilbronner and Bock, 1968)...

Villeneuve, D.L., C.A. Richter, A.L. Blankenship and J.P. Giesy. Rainbow trout cell bioassay-derived relative potencies for halogenated aromatic hydrocarbons comparison and sensitivity analysis. Environ. Toxicol. Chem. 18 879-888, 1999. 

Aromatic Hydrocarbons Comparison with Experimental Data. 179... 

D., Resolution of benzo[a]pyrene in complex mixtures of other polycyclic aromatic hydrocarbons. Comparison of two spectrofluorimetric methods applied to water samples. Analyst, 125, 1321 -1326, 2000. 

VI. THEORETICAL CALCULATION OF THE RELATIVE RATES OF REACTION OF AROMATIC HYDROCARBONS COMPARISON WITH EXPERIMENTAL DATA... 

Table 6. Comparison of Sulfuric Acid and Gaseous SO Sulfonation Reagents for Sulfonating Aromatic Hydrocarbons ...

Random comparisons of predictions with 2.26 versus 2.6 show no consistent advantage for either value, however. It has been suggested to replace the exponent of 0.6 with 0.7 and to use an association factor of 0.7 for systems containing aromatic hydrocarbons. These modifications, however, are not recommended by Umesi and Danner. Lees and Sarram present a comparison of the association parameters. The average absolute error for 87 different solutes in water is 5.9 percent. 

Comparison of localization energies has frequently been applied to prediction of the relative positional reactivity in polycyclic aromatic hydrocarbons. Simple HMO calculations have only marginal success. CNDO/2 and SCF calculations give results which show good correlation with experimental data on the rate of proton exchange. ... 

If, for the purpose of comparison of substrate reactivities, we use the method of competitive reactions we are faced with the problem of whether the reactivities in a certain series of reactants (i.e. selectivities) should be characterized by the ratio of their rates measured separately [relations (12) and (13)], or whether they should be expressed by the rates measured during simultaneous transformation of two compounds which thus compete in adsorption for the free surface of the catalyst [relations (14) and (15)]. How these two definitions of reactivity may differ from one another will be shown later by the example of competitive hydrogenation of alkylphenols (Section IV.E, p. 42). This may also be demonstrated by the classical example of hydrogenation of aromatic hydrocarbons on Raney nickel (48). In this case, the constants obtained by separate measurements of reaction rates for individual compounds lead to the reactivity order which is different from the order found on the basis of factor S, determined by the method of competitive reactions (Table II). Other examples of the change of reactivity, which may even result in the selective reaction of a strongly adsorbed reactant in competitive reactions (49, 50) have already been discussed (see p. 12). 

Geiselbrecht AD, BP Hedland, MA Tichi, IT Staley (1998) Isolation of marine polycyclic aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and comparison of their PAH degradation ability with that of Puget Sound Cycloclasticus strains. Appl Environ Microbiol 64 4703-4710. 

Govindaswami M, DJ Feldjake, BK Kinkle, DP Mindell, JC Loper (1995) Phylogenetic comparison of two polycyclic aromatic hydrocarbon-degrading mycobacteria. Appl Environ Microbiol 61 3221-3226. 

Aqueous solubility is selected to demonstrate the E-state application in QSPR studies. Huuskonen et al. modeled the aqueous solubihty of 734 diverse organic compounds with multiple linear regression (MLR) and artificial neural network (ANN) approaches [27]. The set of structural descriptors comprised 31 E-state atomic indices, and three indicator variables for pyridine, ahphatic hydrocarbons and aromatic hydrocarbons, respectively. The dataset of734 chemicals was divided into a training set ( =675), a vahdation set (n=38) and a test set (n=21). A comparison of the MLR results (training, r =0.94, s=0.58 vahdation r =0.84, s=0.67 test, r =0.80, s=0.87) and the ANN results (training, r =0.96, s=0.51 vahdation r =0.85, s=0.62 tesL r =0.84, s=0.75) indicates a smah improvement for the neural network model with five hidden neurons. These QSPR models may be used for a fast and rehable computahon of the aqueous solubihty for diverse orgarhc compounds. 

Sim PG, Boyd RK, Gershey RM, Gueveemont R, Jamieson WD, Qdilliam MA, and Geegely RJ (1987) A comparison of chromatographic and chromatographic/mass spectrometric techniques for the determination of polycyclic aromatic hydrocarbons in marine sediments. Biomed Environ Mass Spectrosc 14 375-381. 

In Japan, the standard Eco Mark Product Category No. 102 Printing Ink Version 2.6 [26] sets on a voluntary basis standards for an environmentally friendly composition of printing inks. Since introduction of this standard in 1997, more than 90% of all offset inks in Japan were reformulated to inks free from aromatic compounds ( white oil ). To fulfil the above-mentioned standard, the inks should be based on vegetable oils. They should not contain more than 1 vol.% of aromatic hydrocarbons ( white oils ). Additionally, sheet-fed offset inks should not contain more than 30% of crude oil-based solvents and not more than 3% VOC. Web offset inks should contain no more than 45% crude oil solvents (which seems not really to be a progress in comparison to typical standard inks). By the way, it is expected from vegetable oil-based inks that the print products are as deinkable as conventional mineral oil-based offset inks. 

Dzido, T.H., Kossowski, T.E., Matosiuk, D. (2002). Comparison of retention of aromatic hydrocarbons with polar groups in binary reversed-phase high-performance liquid chromatography systems. J. Chromatogr. A 947, 167-183. 

Rabinowitz, J. R., and S. B. Little. 1994. Comparison of Quantum-Mechanical Methods to Compute the Biologically Relevant Reactivities of Cyclopenta-Polycyclic Aromatic-Hydrocarbons. Inti. J. Quant. Chem. 52, 681. 

However, the main use of fluorescence has been in the semi-quantitative determination of aromatic hydrocarbons by extraction into an organic solvent, followed by excitation at a standard wavelength and comparison with the emission from a chosen standard. These techniques have been studied by many workers [38-42],... 

Berset JD, Ejem M, Holzer R, Lischer P (1999) Comparison of different drying, extraction and detection techniques for the determination of priority polycyclic aromatic hydrocarbons in background contaminated soil samples. Anal Chim Acta 383(3) 263-275... 

Ratola N, Lacorte S, Alves A et al (2006) Analysis of polycyclic aromatic hydrocarbons in pine needles by gas chromatography-mass spectrometry. Comparison of different extraction and clean-up procedures. J Chromatogr A 1114 198-204... 

Greenberg, A., F. Darack, R. Harkov, P. Lioy, and J. Daisey. 1985. Polycyclic aromatic hydrocarbons in New Jersey a comparison of winter and summer concentrations over a two-year period. Atmospher. Environ. 19 1325-1339. 

Lin, E.L.C., S.M. Cormier, and J.A. Torsella. 1996. Fish biliary polycyclic aromatic hydrocarbon metabolites estimated by fixed-wavelength fluorescence comparison with HPLC-fluorescent detection. Ecotoxicol. Environ. Safety 35 16-23. 

Miege C, Dugay J, Hennion MC. Optimization, validation and comparison of various extraction techniques for the trace determination of polycyclic aromatic hydrocarbons in sewage sludges by liquid chromatography coupled to diode-array and fluorescence detection. J. Chromatogr. A 2003 995 87-97. 

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. 

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