Alcoholic solutions, essential oils

Every resin is a natural mixtare of several others, which sometimes admit of easy separation by different solvents, such as alcohol, ether, essential oils, alkaline solutions, et cetera. For instance, when certain acid resins are dissolved In alcohol, and an alcoholic solntion of acetate of copper is added, it happens sometimes that only a part of the resin is precipitated. The deposit, which can be readily separated from the liquid, is found occasionally to be but partially dissolved by ... 

C, b.p. 156 C. The most important of the terpene hydrocarbons. It is found in most essential oils derived from the Coniferae, and is the main constituent of turpentine oil. Contains two asymmetric carbon atoms. The (- -)-form is easily obtained in a pure state by fractionation of Greek turpentine oil, of which it constitutes 95%. Pinene may be separated from turpentine oil in the form of its crystalline nitrosochloride, CioHigClNO, from which the ( + )-form may be recovered by boiling with aniline in alcoholic solution. When heated under pressure at 250-270 C, a-pinene is converted into dipentene. It can be reduced by hydrogen in the presence of a catalyst to form... 

Organic from Water An area where pei vaporation may become important is in flavors, fragrances, and essential oils. Here, high-value materials with unique properties are recovered from aqueous or alcohol solutions. 

The chemistry of fenchyl alcohol, Cj HjgO, must be regarded as in a somewhat unsettled state, as questions of isomerism arise which are as yet unsolved. It was ori nally prepared by Wallach by reducing the ketone fenchone, a natural constituent of several essential oils, by means of sodium. Later he obtained it in fairly large quantities as a byproduct in the preparation of fenchone-carboxylic acid, by passing a current of C(X through an ethereal solution of fenchone in the presence of sodium. Fenchyl alcohol has, so far, been found in one essential oil only, namely, that of the root wood of Pinus palustris. 

Esters, or salts of alkyl radicles, such as linalyl acetate, etc., are frequently the most important constituents of essential oils. Their importance is especially noteworthy in such cases as lavender , bergamot, peppermint, and wintergreen oils, and their estimation is very frequently necessary. The principle upon which this depends is the fact that most esters are decomposed by solution of caustic alkali (preferably in alcohol) according to the equation—... 

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. 

Cologne and other Fragrant Waters.—These preparations are mostly solutions of bouquets of essential oils, or extracts, in alcohol, improved by distillation. For common kinds distillation is omitted. 

Enfleurage is a method that is almost obsolete, producing a rather impure product. Thin layers of cold, odourless fat such as lard are coated onto glass plates called chassis and the plant material is spread in layers onto the top of the fat. Other chassis with fat and plant material are stacked onto each other and the essential oil is absorbed into the fat. When the fat is saturated, it is washed with hexane to dissolve the essential oil. After removal of hexane, the residue is washed with alcohol and the resultant solution is evaporated to give purer essential oil, or more strictly an absolute. The true pomades are products of enfleurage as they are the fragrance-saturated fat. 

In aqueous alcoholic solutions, it very readily solubilizes essential oils. Aqueous solutions of hydrophobic drugs (e.g. miconazole, hexetidine, clotrimazole, benzocaine) can also be prepared with Cremophor EL. Cremophor EL has also been used as a solubilizing agent for drugs like cyclosporin A, paclitaxel, and cisplatin. Cremophor LLP is manufactured by purifying Cremophor EL and is therefore suitable for parenteral applications, e.g. Taxol preparations. In oral formulations, the taste of polyoxyl 35 castor oil (Cremophor EL) can be masked by a banana flavor. 

Properties Light-yellowish, essential oil rather pungent, citruslike odor. D 0.887-0.906, refr index 1.468-1.483 solutions are levorotatory. Soluble in 80% alcohol. Combustible. 

A food extract, such as a lemon extract, is really not a chemical extraction but consists of the essential oils that are mechanically pressed out of lemon skin and then kept in a 45% solution of alcohol. A drug extract is called a tincture. Tinctures are usually alcohol solutions and are liquid-solid extractions. Examples are the tincture of iodine, oil of wintergreen, oil of clove, and oil of peppermint. Cosmetic extracts such as ambergris, musk, castor, and benzoin, are called essences and are used to make perfumes. 

It crystallizes in hexagonal prisms veiy bitter fuses at 67" (134".6 F.) loses Aq at 100 (212 F.) and the remainder at 125 (257 F.) becomes colored, swells up, and, finally, bums with a smoky fitune. It does not sublime. It dissolves in 2,200 pts. of cold H,0, in 760 of hot H,0 very soluble in alcohol and chloroform soluble in amyl alcohol, benzene, fatty and essential oils, and ether Its alcoholic solution is powerfully Imvogy-rous, [a) = — 270 .7 at 18 (64 .4 F.), which is diminished by increase of temperature, but increased by the presence of acids. 

The hisnlphuret of carbon is purified by distillation in a very gentle heat, and then forms a very transparent, mobile, colourless liquid, of sp. g. 1.272, sinking, therefore, in water, which has a peculiar offensive smell of putrid cabbage. It is very volatile, boiling at 108" and very combustible, burning with a pale blue flame, and producing sulphurous and carbonic acids. It is insoluble in water, soluble in alcohol, ether, and oils. It dissolves sulphur and phosphorus readily and these solutions, by spontaneous evaporation, yield fine crystals of those elements. It also dissolves camphor, essential oils, and resins. 

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