Neutral fraction, composition

Neutrals. Table XI presents compositional data for the furan and thiophene compound types present in the neutral fractions from the feed and the products. Results for only two reactor samples are given because of insignificant variations in the analytical data for these Z(0) and Z(S) compound types between the four upgraded liquids. Dibenzofurans and dibenzothio-phenes were identified by GC/MS. 

Considering the ligno-holocellulosic composition of wood, it is not surprising that the liquor is divisible into a carbohydrate (neutral) fraction and an aromatic (acidic) fraction, the former of holocellulosic origin and the latter of lignin origin. 

Separation Techniques. The complexity of the organic composition of coal-derived liquids, shale oil, and their related effluents presents a formidable challenge to the analytical chemist. Our approach to this problem has been the classical separation technique based on acid-base-neutral polarity of the organic compounds. We further subdivide the neutral fraction into aromatic and non-aromatic fractions using dimethyl-sulfoxide (DMSO) extraction. DMSO effectively removes multiringed aromatic compounds with great eflBciency (85-95%) for these complex mixtures and thus allows a straightforward analysis for polynuclear... 

Bonnet, J. and S. Neukomm Sur la composition chimique de la fumee du tabac. I. Analyse de la fraction neuter [On the chemical composition of tobacco smoke. 1. Analysis of the neutral fraction] Helv. Chim. Acta 39 (1956) 1724-1733. 

Kaburaki, Y, H. Shigematsn, Y. Mikami, and H. Kusakabe Smdies on the composition of tobacco smoke. XL Relation between vapor phase components and constituents of tobacco (2) Sci. Papers, Cent. Res. Inst., Japan Monopoly Corp. Ill (1969) 143-149. Kaburaki, Y, H. Shigematsn, Y. Yamashita, and H. Kusakabe Studies on the composition of tobacco smoke. XV. Volatile compounds from the neutral fraction of tobacco smoke condensate Agr. Biol. Chem. Japan 35 (1971) 1741-1750. 

Richter, M. Composition of essential oils in tobacco. 4. Analyses of the neutral fraction Ber. Inst. Tabakforsch. (Dresden) 23 (1976) 44-57. 

Schmeltz, L, J. Dooley, R.L. Stedman, and W.J. Chamberlain Composition studies on tobacco. XXII. The nitromethane-soluble neutral fraction of cigaret smoke Phytochemistry 6 (1967) 33-38. 

The current findings of CLA effects on bone fatty acid composition are consistent with previously reported values. For example, CLA reduced 18 ln-9 and total monounsaturated fatty acids in both neutral and polar lipids, and reduced 20 4n-6 in the neutral fraction of liver. This could be due to reduced liver stearoyl-CoA desaturase (A9 desaturase, catalyze the formation of 18 ln-9 from 18 0) expression (16). CLA was reported to decrease the mRNA level of the A9-desaturase enzyme in both liver tissue and hepatocyte cultures (16). More interestingly, the c9,fll CLA isomer, which is implicated as the primary biologically active isomer (21), had no effect on the expression of A9 desaturase compared with the chemically synthesized CLA, which contained as much tl0,cl2 as c9,tll and small amounts of other isomers. This indicates that individual CLA isomers may have their own regulatory functions in a biological system. 

Shigematsu, H., R. Ono, Y. Yamashita, and Y. Kaburaki Studies on Composition of Tobacco Smoke. XVI. Volatile Compounds from the Neutral Fraction of Tobacco Smoke Condensates. Agric. Biol. Chem. 35, 1751 (1971). 

Another widely used technique for die separation of heavy oils into subcomponents is lEC (Ion Exchange Chromatography). In this method, the petroleum samples are separated into acid, base and neutral fractions. Walton reported this technique in 1992, and it has also been used extensively by Green et al. in studying the relationships between the composition of different feedstocks with product slate and composition in catalytic cracking. The properties of the Hamaca resid from Venezuela and its fractions, using the technique developed by Green, were reported by Rahimi et al. and are shown in Table 6. 

Another way to increase the phosphatidylcholine content in lecithin is enzymatic transesterification after the addition of choline. Alternatively, modification can be achieved by the addition of free fatty acids, which make the product more fluid. Chemical modification of lecithin (hydrogenation and hydroxylation of the double bonds of fatty acids) is used to increase its stabihty against oxidation. For specific purposes, a phosphohpid concentrate (>90% ofphospho-hpids) is produced by a selective extraction that separates neutral hpids, especially triacylglycerols and free fatty acids. The most important product for industrial purposes is soy lecithin. Its composition is shown in Table 3.33. Rapeseed lecithin and sunflower lecithin have quite a different phosphohpid fraction composition. 

Sterols are synthesized in both plants and animals. Sterols and their derivatives, such as hormones and vitamin D2, perform various important functions in living organisms depending on their structure. Consequently, sterol products can be derived from several sources. Plant sterols, or phytosterols, are obtained from the unsaponifiable fraction of vegetable oils and fats. The amount of sterol, as well as its composition including fraction of unsaponifiable portion of the respective oil and fats, depends on the raw materials and is characteristic of the particular base material (Table 1). Soya oil represents a widely available source for commercial production of phytosterols. The unsaponifiable portion is separated into a sterol fraction and a tocopherol fraction. A small amount of tocopherol is usually left in the sterol fraction (approximately 4%), which acts as a natural antioxidant in the final product [2]. Plant sterols are also obtained from the black-liquor soap skimming in commercial pulping of wood. The neutral fraction of this so-called tall oil is relatively rich in sterols (approximately 32% of the neutral fraction [3]), and the sterol... 

In a falling film evaporator (4) a water-paraffin mixture is distilled off and completely pumped back to the reactor. The resulting product is separated into a 60% sulfuric acid fraction and paraffin-containing alkanesulfonic acid (5), which is bleached by hydrogen peroxide (6). In a stirred vessel (7) the alkanesulfonic acid is neutralized by 50% sodium hydroxide solution until the pH is exactly 7. The composition of the neutralized product is also given in Table 2. 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

In a study completed during the early development of f.a.b.-m.s., both f.d. and f.a.b. were used to characterize 101 fractions containing neutral oligosaccharides isolated from human milk. Samples were examined as their peracetylated alditols. In subsequent work, the structures of two minor acidic oligosaccharides from human milk were investigated. The per-methylated derivatives were analyzed by f.a.b.-m.s., and their compositions and sequences were defined by the f.a.b. data. Methylation analysis and partial formolysis were the other principal methods used. 

Fractions were pooled as indicated in the figure and analyzed for their sugar compositions (Table 3). The sugar compositions clearly show that most of the neutral sugars were concentrated in the large fragments that eluted close to the void volume of the column (Fraction... 

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