Saponification, fractional

Fractional saponific alkali, will also reveal 1 The followinp table ition, with the use of varyieg amc c presence of terpinyl acetate, will indicate the differences observ d when about... 

The third category is the basis of many commonly used methods. In general, the steps in this category are solvent extraction to remove the lipid fraction, saponification, methylation to fatty acid esters, separation using chromatographic columns and GC analysis. Martin-Hemandez... 

Linalool can also be made along with nerol and geraniol via the hydrochlorination of myrcene. After conversion of the chlorides to acetates followed by saponification of the acetates, the mixture of alcohols is obtained. Fractionation of the mixture gives linalool in about 95% purity, but the presence of close boiling impurities prohibits manufacture of a perfiimery-quahty product. 

Provitamin D. Provitamin is made from cholesterol, and its commercial production begias with the isolation of cholesterol from one of its natural sources. Cholesterol occurs ia many animals, and is generally extracted from wool grease obtained by washing wool after it is sheared from sheep. This grease is a mixture of fatty-acid esters, which contain ca 15 wt % cholesterol. The alcohol fraction is obtained after saponification, and the cholesterol is separated, usually by complexation with 2iac chloride, followed by decomplexation and crystallisation. Cholesterol can also be extracted from the spiaal cords and brains of animals, especially catde, and from fish oils. 

In 1899 Thoms isolated an alcohol from Peru balsam oil, which he termed peruviol. This body was stated to have powerful antiseptic properties, but has not been further investigated until Schimmel Co. took up the subject. The oil after saponification was fractionated, and after benzyl alcohol had distilled over, a light oil with characteristic balsamic odour passed over. It boiled at 125° to 127° at 4 mm., and had a specific gravity 0 8987, optical rotation -1- 12° 22, and refractive index 1-48982. This body appeared to be identical with Hesse s nerolidol, whilst in physical and chemical properties it closely resembles peruviol. The characters of the various preparations were as follows —... 

Pickard, Lewcock and Yates have prepared fenchyl alcohol by the reduction of laevo-rotatory. On conversion into its hydrogen phthalate and fractionally crystallising the magnesium and cinchonine salts, they obtained a fraction, which on saponification yielded Za w-fenchyl alcohol, having a specific rotation of - 15 5°, which is probably the correct value for this figure. 

The author has recommended the examination of the last 10 per cent, left on evaporation of the oil on a water-bath, since the heavy artificial esters accumulate in this fraction. The refractive index of this 10 per cent, should not be below 1 5090, and the saponification value should not exceed 190. The following figures (see p. 317) represent nine samples of adulterated oil, all sold as genuine bergamot oil. 

The amount of residual sulfonate ester remaining after hydrolysis can be determined by a procedure proposed by Martinsson and Nilsson [129], similar to that used to determine total residual saponifiables in neutral oils. Neutrals, including alkanes, alkenes, secondary alcohols, and sultones, as well as the sulfonate esters in the AOS, are isolated by extraction from an aqueous alcoholic solution with petroleum ether. The sulfonate esters are separated from the sultones by chromatography on a silica gel column. Each eluent fraction is subjected to saponification and measured as active matter by MBAS determination measuring the extinction of the trichloromethane solution at 642 nra. (a) Sultones. Connor et al. [130] first reported, in 1975, a very small amount of skin sensitizer, l-unsaturated-l,3-sultone, and 2-chloroalkane-l,3-sultone in the anionic surfactant produced by the sulfation of ethoxylated fatty alcohol. These compounds can also be found in some AOS products consequently, methods of detection are essential. 

After identifying the optimal etherification conditions, our attention turned to isolation of 18 in diastereomerically pure form. Diastereomers 18 and 19 were not crystalline, but, fortunately, the corresponding carboxylic acid 71 was crystalline. Saponification of the crude etherification reaction mixture of 18 and 19 with NaOH in MeOH resulted in the quantitative formation of carboxylic acids 71 and 72 (17 1) (Scheme 7.22). Since the etherification reaction only proceeded to 75-80% conversion, there still remained starting alcohol 10. Unfortunately, all attempts to fractionally crystallize the desired diastereomer 71 from the crude mixture proved unfruitful. It was reasoned that crystallization and purification of 71 would be possible via an appropriate salt. A screen of a variety of amines was then undertaken. During the screening process it was discovered that when NEt3 was added... 

Generally, alkaline saponification in hydroalcoholic KOH is the most widespread approach [11 13]. This allows us to cleave ester bonds and, if necessary, to separate the saponifiable fraction (acids) and unsaponificable fraction (alcohols, sterols, and hydrocarbons). Generally, 3 h of saponification in 10% KOH in water/methanol (3 1) at 60 °C achieves a quantitative yield for triglycerides. Wax esters are less prone to hydrolysis and generally need stronger conditions. Quantitative hydrolysis of beeswax long chain esters has been obtained using 10% KOH in ethanol assisted by microwaves, for 60 min at 80 °C and at 200 W [21],... 

Figure 7.6 Total ion current profile of the acidic fraction of a sample from a linseed oil reference paint layer (Opificio delle Pietre Dure, Florence, Italy), after saponification and silylation of carboxylic and hydroxyl ic groups [9]...

The cooled reaction product is treated with 200 cc. of water, the layer of oil separated, washed once with a second portion of water, and subjected to distillation in vacuo. The first fraction of the distillate contains benzyl alcohol together with unchanged aldehyde, as well as a small quantity of water. The temperature then rises rapidly to the boiling-point of benzyl benzoate, when the receivers are changed. The product boils at 184-185°/15 mm., and analysis by saponification shows it to consist of 99 per cent ester. A yield of 410-420 g. is obtained, which corresponds to 90-93 per cent of the theoretical amount. This benzyl benzoate supercools readily, but after solidifying... 

Few analytical methods are available for the determination of total petroleum hydrocarbons in biological samples, but analytical methods for several important hydrocarbon components of total petroleum hydrocarbons may be modified. Most involve solvent extraction and saponification of lipids, followed by separation into aliphatic and aromatic fractions on adsorption columns. Hydrocarbon groups or target compounds are determined by gas chromatography-flame ionization or... 

Retinoids The challenge in fat-soluble vitamins analysis is to separate them from the lipid fraction that contains interferents. Alkaline hydrolysis, followed by LLE, is widely applied to remove triglycerides. This technique converts the vitamin A ester to all-trani-retinol. A milder process, which does not hydrolyze vitamin A ester, is alcoholysis carried out with metha-nolic KOH solution under specific conditions that favor alcoholysis rather than saponification. A more accurate explanation of this technique is reported in the book Food Analysis by FIPLC [409]. For some kind of matrices a simple liquid extraction can be sufficient with [421-423] or without [424,425] the purification... 

Isolation from Essential Oils. Geraniol is isolated from citronella oils and from palmarosa oil. Fractional distillation of, for example, Java citronella oil (if necessary after saponification of the esters present) yields a fraction containing ca. 60% geraniol, as well as citronellol and sesquiterpenes. 

A product with a higher geraniol content and slightly different odor quality for use in fine fragrances is obtained by fractionating palmarosa oil after saponification of the geranyl esters. 

After saponification and fractional distillation of the resulting alcohols, a fraction is obtained that contains ca. 98% geraniol. 

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