Extraction of fatty alcohol

Transfer the hydrolysed solution quantitatively to a separating funnel. If the solution contains unhydrolysed surfactants, e.g. alkylbenzene sulphonate, dilute with an equal volume of ethanol. 

Extract three times with 50 ml petroleum ether. 

Combine the petroleum ether extracts and wash with 25 ml water or 50% aqueous ethanol. 

Re-extract the water or aqueous ethanol with 25 ml petroleum ether and add this to the main extract. 

Transfer the extract quantitatively to a tared beaker and evaporate to a low volume on a steam bath (caution flammable vapour). Complete evaporation under a jet of air without heating. 

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Proceed as for extraction of fatty alcohol (section 5.3.2). There is no need to avoid heating the extracted fatty acid as these are essentially in volatile. The fatty acid may be dissolved in ethanol and titrated with alcoholic alkali to phenolphthalein or converted to its methyl ester and examined by GLC. 

Determination of monoalkyl sulphosuccinatCy alkaline hydrolysis and extraction of fatty alcohols... 

Extraction of fatty alcohol with petroleum ether (section 5.3.2), or of... 

Alkylpolyglycosides acid hydrolysis and extraction of fatty alcohol. Alkanolamides and their ethoxylates acid hydrolysis, extraction of fatty acid, titration of alkanolamine or ethoxylated alkanolamine. 

Total aliphatic alcohol content does not usually exceed 35 mg/100 g oil. In olive-extracted oil, the level of fatty alcohols is ten times higher or even greater. Dry climatic conditions and high temperatures may cause high alkanol content of olive oil. 

Waxes. Waxes are esters of fatty alcohols with fatty acids. The content of olive oil wax content is very low and does not exceed 35 mg/100 g. Extracted olive oils have a very high wax content and this difference is used officially for the... 

Extraction of fatty acid (acyl isethionates) or of fatty alcohol (sulpho-succinates)... 

Extraction of ethoxylated alcohol (by deionisation) gives ether sulphate Fatty acid by petroleum ether extraction and alkali titration (lower ethoxylates also extracted) gives glyceride sulphate Extraction of fatty amine and acid titration (lower ethoxylates also extracted) gives sulphosuccinamate... 

Wax ester biosynthesis probably involves an acyl transfer mechanism. The high thioesterase activity found in crude plant extracts makes it difficult to demonstrate acyl-CoA involvement in wax ester synthesis. However, partial purification of an acetone powder extract from the leaves of B. oleracea gave a protein fraction that catalyzed an acyl-CoA-dependent esterification of fatty alcohols (222). Additionally the acetone powder extract from B. oleracea leaves appeared to catalyze the direct transfer of acyl moieties from phospholipids to fatty alcohols. The leaf extract also catalyzed under appropriate conditions the esterification of fatty alcohols to free fatty acids. The transacylase mechanism is likely to be the main mechanism of wax ester synthesis in vivo. The fact that labeled wax esters were synthesized by a membrane-bound microsomal fraction from Hordeum vulgare leaves following incubation with radioactive alcohols, but not after incubation with free fatty acids (17), is consistent with the proposed acyl transfer mechanism. In E. gracilis the acyl-CoA reductase is functionally coupled to the acyl transferase (227). Both of these activities were solubilized from the microsomes... 

Alcohols may be released from the esterified form by any of the hydrolytic or transesterification procedures described in Chapter 4. If a pure wax ester fraction is hydrolysed, the alcohols are obtained simply by solvent extraction of the alkaline solution. On the other hand, when other lipids are present, it is advisable to isolate them as a class by adsorption chromatography. TLC on layers of silica gel G with the elution system described for simple lipid separations in Chapter 2, i.e. with hexane-diethyl ether-formic acid (80 20 2 by volume) as the mobile phase, is usually used. With such a system, any secondary alcohols migrate ahead of primary alcohols, which in turn are slightly less polar than cholesterol diols migrate just in front of monoacylglycerols. If cholesterol is present in an extract, it may be necessary to re-run the plate in the same direction to obtain additional resolution and ensure that primary alcohols and cholesterol are fully separated. Procedures of this kind were utilised to isolate trace levels of fatty alcohols from animal tissues, for example [108,662,904]. When wax esters are transesterified, the methyl esters and free alcohols can be separated on a mini-column of... 

Many standard procedures are available for studying adsorption by volumetric or titrimetric methods. Adsorption of fatty acid [17] has frequently been determined by titration with aqueous alkali, even if the fatty acid was previously dissolved in organic solvent. Extraction of fatty acid from the solvent caused no problems, especially if warm ethyl alcohol is added [13], but the validity of the method needs to be checked by titration of a known sample each time. 

Using a spectrophotometric assay to detect feruloyl-CoA transferase activity in enzymic extracts of 7-day suberized potato tuber discs, we tested a series of fatty alcohols or acids as potential acceptors of the feruloyl moiety (Table 1). 

This determination is best made by HPLC or CE, as described in Chapters 7 and 11. Under the proper conditions, a single peak is obtained for nonionic impurities. The standard extraction method for unsulfated material in alcohol sulfates (ASTM D 1570) is not appropriate for ethoxysulfates because the solubility characteristics of ethoxylated fatty alcohols differ from those of fatty alcohols. The products with higher degrees of ethoxylation will not be completely extracted and emulsion formation may altogether prevent extraction. 

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. 

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. 

For a further separation of the sulfonated surfactants the latter are heated for 4 h with 2 N HC1. The methyl ester sulfonates are split into methanol and a-sulfo fatty acids, which form disodium salts after neutralization with NaOH. The product mixture from acid hydrolysis can be separated by extraction with petroleum ether. For example, the fatty alcohols formed from fatty alcohol sulfo-... 

Figure 1.7 Typical zero-order and corresponding second-derivative electronic absorption spectra of ethanol-reconstituted lipid/chloroform extracts of autoxidized model polyunsaturated fatty-acid compounds and inflammatory synovial fluid obtained after (1) reduction with NaBH4 and (2) dehydration with alcoholic H2S04- (a) Methyl linoleate subsequent to autoxidation in air at ambient temperature for a period of 72 h (—), or exposure to a Fenton reaction system containing EDTA (5.75 x 10 mol/dm ), H2O2 (1.14 X 10 mol/dm ) and Fe(ll) (5.75 x IO mol/dm ) as an aqueous suspension (—) (b) as (a) but with methyl linolenate (c) untreated rheumatoid knee-joint synovial fluid.

Fatty alcohol- (or alkyl-)ethoxylates, CoE, are considered to be better candidates for LLE based on their ability to induce rapid phase separation for Winsor II and III systems. (Winsor III systems consist of excess aqueous and organic phases, and a middle phase containing bicontinuous microemulsions.) However, C,E,-type surfactants alone cannot extract biomolecules, presumably because they have no net negative charge, in contrast to sorbitan esters [24,26,30,31]. But, when combined with an additional anionic surfactant such as AOT or sodium benzene dodecyl sulfonate (SDBS), or affinity surfactant, extraction readily occurs [30,31]. The second surfactant must be present beyond a minimum threshold value so that its interfacial concentration is sufficiently large to be seen by... 

In a typical example of reactive extraction a fatty acid ester was easily formed by adding a small amount of an alcohol to a fatty acid metal salt and extracting at 315 °C [647]. This method was applied to PP/calcium stearate and PP/zinc stearate containing pellets the presence of the fatty acid metal salts was confirmed by GC-MS. 

Wood contains a small proportion (usually less than 5%) of components which are extractable by organic solvents such as ethanol or dichloromethane. The proportion of these extractives varies in hardwoods and softwoods and also between species. Although many of these substances are removed during the chemical pulping process, some may still be retained in the final sheet of paper. Their chemical composition is very varied, and they include alkanes, fatty alcohols and acids (both saturated and unsaturated), glycerol esters, waxes, resin acids, terpene and phenolic components. The proportion which remains in pulp and paper depends upon the pulping process used. In general, acidic components such as the resin and fatty acids are relatively easily removed by alkali by conversion to their soluble... 

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