Hydrocarbons identification

Table 1. Typical hydrocarbon identifications structures are shown in Fig. 1) and chemical compositions (representative ...

In contrast to traditional methods for total petroleum hydrocarbons that report a single concentration number for complex mixtures, the fractionation methods report separate concentrations for discrete aliphatic and aromatic fractions. The petroleum fraction methods available are GC-based and are thus sensitive to a broad range of hydrocarbons. Identification and quantification of aliphatic and aromatic fractions allows one to identify petroleum products and evaluate the extent of product weathering. These fraction data also can be used in risk assessment. 

Petroleum hydrocarbon identification was based primarily on the GC-FID chromatogram patterns of the saturated and unsaturated... 

Aeromonas hydrophila by polycyclic aromatic hydrocarbons Identification of hydrolysis LC ESI... 

Its charge transfer complexes with aromatic hydrocarbons have characteristic melting points and may be used for the identification and purification of the hydrocarbons. 

Identification of normal paraffins by chromatography presents no special problems with the exception of biodegraded crudes, they are clearly distinguished. The problem encountered is to quantify, as shown in Figure 3.14, the normal paraffin peaks that are superimposed on a background representing other hydrocarbons. 

Identification of Aromatic Hydrocarbons. Picric acid combines with many aromatic hydrocarbons, giving addition products of definite m.p. Thus with naphthalene it gives yellow naphthalene picrate, C oHg,(N08)jCeHiOH, m.p. 152°, and with anthracene it gives red anthracene picrate, C 4Hio,(NOj)jCeHjOH, m.p. 138 . For practical details, see p. 394. 

The following reactions will assist the student in the identification of halogenated aromatic hydrocarbons. 

Although many sterols and bile acids were isolated in the nineteenth century, it was not until the twentieth century that the stmcture of the steroid nucleus was first elucidated (5). X-ray crystallographic data first suggested that the steroid nucleus was a thin, lath-shaped stmcture (6). This perhydro-l,2-cyclopentenophenanthrene ring system was eventually confirmed by the identification of the Diels hydrocarbon [549-88-2] (4) and by the total synthesis of equilenin [517-09-9] (5) (7). 

Antimony trichloride is used as a catalyst or as a component of catalysts to effect polymerisation of hydrocarbons and to chlorinate olefins. It is also used in hydrocracking of coal (qv) and heavy hydrocarbons (qv), as an analytic reagent for chloral, aromatic hydrocarbons, and vitamin A, and in the microscopic identification of dmgs. Liquid SbCl is used as a nonaqueous solvent. 

Qualitatively, the spark source mass spectrum is relatively simple and easy to interpret. Most instrumentation has been designed to operate with a mass resolution Al/dM of about 1500. For example, at mass M= 60 a difference of 0.04 amu can be resolved. This is sufficient for the separation of most hydrocarbons from metals of the same nominal mass and for precise mass determinations to identify most species. Each exposure, as described earlier and shown in Figure 2, covers the mass range from Be to U, with the elemental isotopic patterns clearly resolved for positive identification. 

The case study has documented the investigation and root cause analysis process applied to the hydrocarbon explosion that initiated the Piper Alpha incident. The case study serves to illustrate the use of the STEP technique, which provides a clear graphical representation of the agents and events involved in the incident process. The case study also demonstrates the identification of the critical events in the sequence which significantly influenced the outcome of the incident. Finally the root causes of these critical events were determined. This allows the analyst to evaluate why they occurred and indicated areas to be addressed in developing effechve error reduchon strategies. 

The above considerations indicate the complex nature of the hydrocarbons known as caryophyllene. For practical purposes, however, the compounds indicated are obtained of practically definite melting-points, and, in spite of the complicated isomerism existing amongst most of them, are useful for identification of the sesquiterpene or mixture of sesquiterpenes, occurring naturally and known as caryophyllene . 

Single-event microkinetics describe the hydrocarbon conversion at molecular level. Present day analytical techniques do not allow an identification of industrial feedstocks in such detail. In addition current computational resources are not sufficient to perform simulations at molecular level for industrial feedstock conversion. These issues are addressed using the relumping methodology. 

Hearn EM, JJ Dennis, MR Gray, JJ Foght (2003) Identification and characterization of the emhABC efflux system for polycyclic aromatic hydrocarbons in Pseudomonas fluorescens cLP6a. J Bacterial 185 6233-6240. 

Demanhche S, C Meyer, J Micoud, M Louwagie, JC Wilson, Y Jouanneau (2004) Identification and functional analysis of two ring-hydroxylating dioxygenases from a Sphingomonas strain that degrades various polycyclic aromatic hydrocarbons. Appl Environ Microbiol 70 6714-6725. 

Vila J, Z Lopez, J Sabate, C Minguillon, AM Solanasm, M Grifoll (2001) Identification of a novel metabolite in the degradation of pyrene by Mycobacterium sp. strain API actions of the isolate on two- and three-ring polycyclic aromatic hydrocarbons. Appl Environ Microbiol 67 5497-5505. 

Shen Y, LG Stehmeier, G Voordouw (1998) Identification of hydrocarbon-degrading bacteria in soil by reverse sample genome probing. Appl Environ Microbiol 63 637-645. 

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