Glycerin solutions, diluted

Some pharmacopeias also contain specifications for diluted glycerin solutions. The JP 2001 contains a monograph for glycerin that contains 84-87% of propane-1,2,3-triol (C3H8O3). The PhEur 2005 contains a monograph for glycerol 85 per cent that contains 83.5-88.5% of propane-1,2,3-triol... 

Since fermentation takes place in a dilute aqueous solution, the reaction continues until the alcohol concentration approaches about 14%. At higher concentrations, the process becomes self-inhibitory. By-products from starch fermentation to ethanol can include higher-molecular-weight alcohols, glycerine, and ethers. Usually no more than 10% starch is converted to these compounds. Atmospheric distillation, vacuum distillation, and membrane separation techniques can be used to recover ethanol from the final fermented product. The distillate bottoms, called stillage, are recovered as a by-product for animal feed. A biomass fermentation flow diagram is provided in FIGURE 12-2. 

When drilling a rubber stopper, you will find it prudent to wet the tip of the bit with glycerin or a dilute ammonia solution and drill on a table as indicated above, or in a special stopper drill (Fig. 27). 

If sections of a resin containing plant part are placed in a saturated aqueous solution of copper acetate for a week or two and mounted in dilute glycerin, the resin will be stained an emerald green. 

Problems Even diluted protein solutions often plug the filters completely. If the sample is also viscous (e.g., buffered with 10% glycerin), even centrifuging for several hours is of no use. The sample does not even think about passing the filter. The filter rips at higher centrifu-... 

Nitro isobutyl glycerine trinitrate is soluble to concentrated sulfuric acid and dissociated to produce nitric acid. It is sensitive to react with bases as saponification reaction, especially for hydroxides of alkali metals and alkali-earth metals. Nitro isobutyl glycerine trinitrate can be destroyed by NaOH. In water or dilute acids, it is diflhcult to be hydrolyzed. However, in dilute base solution, it can be hydrolyzed to a yellow solution with a hydrolyzation constant of 1.81 x 10... 

As for the tension of the liquid, it does not differ in an appreciable way of that of the soap solution of which it is partly made. Indeed, the tension of a liquid film can ( 158) be represented by the expression or in which p is the pressure exerted by a bubble of the same liquid on the air that it imprisons, and d the diameter of this bubble however we saw ( 121) that with regard to the glyceric liquid, one has, at ordinary temperatures, pd = 22.56 one deducts = 5.64 from them, a value which is also that of the tension of a film of our soap solution This identity should not surprise according to the research of Dupre, the tension of a soap solution hardly varies by very considerable changes even in the proportion of water, and undoubtedly the same thing takes place when one dilutes the solution with glycerin. 

The employment of absolutely pure fats may be regarded as the main condition for the production cf pure glycerine in this way, because otherwise the foreign matters remain behind in the glycerine solution, and cannot be quite completely removed from it. The fats to be employed therelore—more especially in the case of animal tallow—niust, before they are ready for saponification, be pmified with the utmost care, and this is accomplished by treatment of the same with very dilute sulphuric acid or soda lye, with simultaneous heating. All membranous parts, which are mixed with the tallow, are thereby destroyed, and the decomposition products arising dissolve in the acid or alkaline liquid, on which finally floats the pure melted fat, which is either moulded into blocks, or immediately brought into the decomposition vessel. 

The freezing-point of glycerine diluted with water depends on the water content. The following table gives the specific gravity of aiiueous glycerine solutions determined at 15 and the freezing-points —... 

The presence of sulphuric acid, generally in tlus form of calcium sulphate (gypsum), can Iks ascertained by mixing tire diluted glycerine with a solution of barium cliloride a resultant white deposit provcjs tlio presence of sulphuric acid. If the deposit resulting from the barium chloride is soluble., in hydrochloric acid, this proves the pres( nc( of ])hos )hori< acid also. 

Functional Nail-Care Products. Cuticle removers are solutions of dilute alkaHes that faciHtate removal, or at least softeniag, of the cuticle. Formulations containing as much as 5% potassium hydroxide have been reported. Such preparations may contain about 10% glycerine to reduce dryiag, and thickeners, such as clays, to reduce mnoff Lipids and other conditioners are iacluded to reduce damage to tissues other than the cuticle. 

A standard solution was prepared in 50% acetonitrile and water having a known concentration of about 100. ig of glycerin per milliliter. Then 1.0 g of Nasonex was transferred into a 200-mL volumetric flask. About 30 mg of calcium chloride was added and diluted to volume with 50% acetonitrile in water and mixed. A portion of standard and sample solutions were filtered through a 0.45- xm nylon syringe filter. Equal volumes (1. iL) of standard and sample solutions were injected separately into the chromatographic system. 

Piitz [11] obtained a patent for the preparation of dinitroglycerine relatively free from the trinitrate by dissolving 1 part of glycerine in 3.3 parts of nitric acid (sp. gr. 1.5) below 15°C. The solution was diluted with 1 part of water and neutralized with calcium carbonate. The product was separated as an oil and a small quantity was extracted with ether from the aqueous solution. 

Free Acids and Bases. — On diluting 10 cc. of glycerin with 50 cc. of water, the solution should not affect red or blue litmus paper. 

Hydrochloric Acid (Chlorides). — 5 cc. of glycerin diluted with 25 cc. of water should exhibit at most a slight, opalescent turbidity on the addition of silver nitrate solution. 

Example 3. Kn of I2 between glycerine and CC14 (xgly/xccl4) is 0.50 at xgly = 0.0001 and is 0.40 at xgly = 0.002. Assuming that both solutions are ideally dilute at the lower concentration and that the... 

Amyris Oil, West Indian Type, occurs as a clear, pale yellow, viscous liquid having a distinct odor suggestive of sandalwood. It is the volatile oil obtained by steam distillation from the wood of Amyris balsamifera L. (Fam. Rutaceae). It is soluble in most fixed oils and usually in mineral oil. It is soluble in an equal volume of propylene glycol, the solution often becoming opalescent on further dilution. It is practically insoluble in glycerin. 

Assay Preparation Transfer about 4 g of sample, accurately weighed, into a 250-mL Erlenmeyer flask, and add 80 mL of 0.5 N potassium hydroxide and 0.5 mL of phenolphtha-lein TS. Connect an air condenser at least 65 cm long to the flask, and heat the mixture on a hot plate for about 2.5 h. Remove the air condenser and add approximately 10% phosphoric acid to the hot mixture until it is definitely acid to Congo red test paper. Reconnect the air condenser, and heat until the fatty acids are liquified and clear. Cool, and transfer the mixture into a 250-mL separator with the aid of small portions of water and hexane. Extract the liberated fatty acids with three successive 25-mL portions of hexane, and collect the extracts in a second separator. Wash the combined hexane extracts with two 25-mL portions of water, and add the washings to the separator containing the water layer. Retain the combined hexane extracts for the determination of total fatty acids. Transfer the contents of the first separator to a 250-mL beaker, heat on a steam bath to remove traces of hexane, filter through acid-washed, fine-texture filter paper into a 500-mL volumetric flask, and finally dilute to volume with water (Solution I). Pipet 25.0 mL of this solution into a 100-mL volumetric flask, and dilute to volume with water (Solution II). Retain the rest of Solution I for the determination of Glycerin (below). 

Maltol occurs as a white, crystalline powder with a characteristic caramel-butterscotch odor, and is suggestive of a fruity-strawberry aroma in dilute solution. One gram dissolves in about 82 mL of water, in 21 mL of alcohol, in 80 mL of glycerin, and in 28 mL of propylene glycol. 

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