Hydrocarbon extracts

Destmction of the aluminum complex with ammonia then permits hydrocarbon extraction of the alkaloid. The alkaloid is subsequently both isolated and used as its tartrate salt. This nonnarcotic dmg, for which tolerance may develop, is frequently used orally with caffeine (16) for treatment of migraine it acts to constrict cerebral blood vessels, thus reducing blood flow to the brain. 

Concrete. Hydrocarbon extracts of plant tissue, concretes are usually soHd to semisoHd waxy masses often containing higher fatty acids such as lauric, myristic, palmitic, and stearic as well as many of the nonvolatiles present in absolutes. 

Resin and Resinoid. Natural resins are plant exudates formed by the oxidation of terpenes. Many are acids or acid anhydrides. Prepared resins are made from oleoresins from which the essential oil has been removed. A resinoid is prepared by hydrocarbon extraction of a natural resin. 

Jasmine. Jasmine is one of the most precious florals used ia perfumery. The concrete of jasmine is produced by hydrocarbon extraction of flowers from Jasminum officinale (var. GrandijJorum). The concrete is then converted to absolute by alcohoHc extraction. It is produced ia many countries, the most important of which is India, followed by Egypt. Jasmine products are rather expensive and are produced ia relatively small amounts compared with other materials. However, jasmine is particularly important ia perfume creation for its great power and aesthetic quaUties. Eour of the principal odor contributors to jasmine are OT-jasmone [488-10-8] (14), methyl jasmonate [91905-974-] (15), benzyl acetate [140-11 ], and iudole [120-72-9] (16). 

Only TTE is considered because it directly impacts the turboexpander s hydrocarbon extraction (liquid production), thereby directly... 

Figure 1.17 Separation of large ring polycyclic aroaatic hydrocarbons extracted from carbon black on a 1.8 x 0.2 n I.D. fused silica capillary column packed with 3 micrometer spherical octadecylsllanized silica gel eluted with a stepwise solvent gradient at a flow rate of 1.1 mlcroliters/min with an inlet pressure of about 360 atmospheres. Under isocratic conditions this column yielded ca. 225,000 theoretical plates. (Reproduced with permission from ref. 238. Copyright Friedr. Vieweg t Sohn).

Aromatic hydrocarbons were found in more recent analyses pyrene, fluoran-threne, phenanthrene and naphthalene in the ratio of 10 10 5 1 (Cronin, 1998). The majority (around 70%) of the hydrocarbons extracted from the Murchison meteorite are polar compounds such as ... 

Hydrocarbon Extraction with CI3CF3, then adsoption on Si02 Thermistor 5 [26]... 

Analysis of variance was used to assess the effects on polyaromatic hydrocarbons extraction at the 99% confidence level for the four factors varied. The percentage of 14C in the extract and soil residue does not total 100% because of degradation and volatilization during incubation and due to losses during analysis. The data are presented in Table 2.3 and represent the average of the three replicates for the extract or soil residue. 

When other sediments known to support PCB dechlorination were inoculated with PCB-dechlorinating microorganisms and amended with incremental increases of pure petroleum hydrocarbons (0-4 wt%) or 6.2 % petroleum hydrocarbons extracted from Silver Lake sediments, a reduction in both the rate and extent of PCB dechlorination occurred. 

Thus, as often occurs in petroleum science (Speight, 1999), the definition of total petroleum hydrocarbons depends on the analytical method used because the total petroleum hydrocarbons measurement is the total concentration of the hydrocarbons extracted and measured by a particular method. The same sample analyzed by different methods may produce different values. For this reason, it is important to know exactly how each determination is made since interpretation of the results depends on understanding the capabilities and limitations of the method. If used indiscriminately, measurement of the total petroleum hydrocarbons in a sample can be misleading, leading to an inaccurate assessment of risk. 

When the reaction has progressed to the desired stage (Note 6), the flow of air is stopped and the mixture is filtered. After the filtrate has been extracted with two 350-ml. portions of petroleum ether (b.p. 30-60°), the combined hydrocarbon extracts are washed successively with two 100-ml. portions of 2N hydrochloric acid and three 100-ml. portions of water. The petroleum ether is distilled from the solution, heated in a water bath, through a 60-cm. Vigreux column, and the residual liquid is distilled under reduced pressure. The fraction, b.p. 64-65° (1.0 mm.) or 132-134° (35 mm.), is collected as 39.5-52.0 g. (64-85%) of colorless liquid, 1.4846-1.4850. This distillation fraction contains (Note 6) 80-90% of the ci5-cyclododecene (51-76%) accompanied by 10-20% of a mixture of cyclododecane and ai,ira s-l,5-cyclododecadiene (Note 7). If desired, the cis-cyclododecene may be further purified by preparative chromatography or separation of the silver nitrate-olefin addition complex (Note 8). 

Feedstock /oTotal Coke leco %CCR % Hydrocarbons Extracted %Total Coke LECO after the Extraction... 

Powell, R. W., "Hydrocarbon Extraction of Acid Mine Drainage, ... 

The determination of the strength of the Lewis acids MF , has been carried out in various solvents using the conventional methods. Numerous techniques have been applied conductivity measurements, cryoscopy, aromatic hydrocarbon extraction,53,84 solubility measurements,85-87 kinetic parameters determinations,52,88,89 electroanalytical techniques (hydrogen electrode),90-93 quinones systems as pH indicators,94-97 or other electrochemical systems,98 99 IR,100,101 and acidity function (//,) determinations with UV-visible spectroscopy,8 9 14 19 102-105 or with NMR spectros-copy.20-22,44-46,106-108 Gas-phase measurements are also available.109-111 Comparison of the results obtained by different methods shows large discrepancies (Table 1.2). 

Natural gasoline a mixture of liquid hydrocarbons extracted from natural gas (q.v.) suitable for blending with refinery gasoline. 

A large series of cuticular hydrocarbons extracted from the female stable fly, Stomoxys calcitrans, is reported to function as a sex pheromone (47). (Z)-9-Hentriacontene, (Q-9-tritriacontene, and methyl-branched hentria- and tritriacontenes possessed activity as sexual releasers. In addition, mono- and dimethyl-substituted hentria- and tritriacontanes were also demonstrated to induce mating-strike behavior in male flies. However, these compounds may actually function as psychedelics, as does (Z)-9-tricosene for the housefly (45). 

With the growth in economic potential seen recently in the Circum-Black Sea countries the environmental stress may be aggravated. The main causes include construction of new and rehabilitation of existing sea ports, revival of the merchant and tanker fleet, consolidation of the naval component, construction of oil and gas pipelines and hydrocarbon extraction, development of health resorts and recreation activities. 

Polymeric Types. When extreme resistance to volatility, marring, migration, and hydrocarbon extraction is required, polymeric plasticizers —the reaction product of aliphatic dicarboxylic acids and low molecular weight diols—are used. Performance varies directly as molecular weight. 

The mixture of reaction product and triphenylphospbine oxide (16), which mixture is gelatinous owing to the alkali metal salt formed, enters an extraction column e, in which the desired reaction product, after acidification with sulfuric acid, is extracted, in counter-current, by hydrocarbons. In a second column, the hydrocarbon extract is washed, also continuously, with aqueous alcohol in order to remove the last residues of triphenylphosphine oxide (16). After concentration, under mild conditions, of the hydrocarbon extract, the all-trans vitamin A acetate (9) formed in the reaction crystallizes out and is separated off. The cis isomer, which does not crystallize, remains in the mother liquor and can be converted, according to one of the above-mentioned techniques, into the all-trans compound. 

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