Charcoal, animal purification

For purification, transfer the acid to a 150 ml. flask containing 60 ml. of water, boil the mixture under reflux, and then add acetic acid in 5 ml. portions down the condenser until almost all the solid has dissolved avoid an excess of acetic acid by ensuring that the solvent action of each addition is complete before the next portion is added. A small suspension of insoluble impurity may remain. Add 2 g. of animal charcoal, boil the solution again for 10-15 minutes, and then filter it through a preheated Buchner funnel. Cool and stir the filtrate, which will deposit pale cream-coloured crystals of the acid. Collect as before and if necessary repeat the recrystallisation. Yield of pure acid, 9 g. m.p. 227-229°. 

Adipic acid [124-04-9] M 146.1, m 154 , pK 4.44, pK 5.45. For use as a volumetric standard, adipic acid was crystd once from hot water with the addition of a little animal charcoal, dried at 120 for 2h, then recrystd from acetone and again dried at 120 for 2h. Other purification procedures include crystn from ethyl acetate and from acetone/petroleum ether, fusion followed by filtration and crystn from the melt, and preliminary distn under vac. 

Payen gives a description of a process by which the purification is rendered more complete, obviating at the same time all danger in the manipulation. It consists in causing it to pass, when in a state of fusion, through granular animal charcoal. Th apparatus consists of a cylindrical vessel provided with a false bottom,... 

HCN) of 50% hydrocyanic acid are gradually added (caution /). The mixture is allowed to stand, with frequent shaking, for 12 hours, and then a mixture of 400 c.cs. (excess) of cone, hydrochloric acid (D. 1 19) and 200 c.cs. of water is added. This produces a lumpy precipitate, which is dissolved by prolonged boiling in a flask another 200 c.cs. of water are added, and the boiling continued for 2 hours more. The mixture is finally evaporated to dryness on a water bath to remove hydrochloric acid. The residue is warmed with about 60 c.cs. of water and made faintly alkaline with ammonia. When cold, the leucine which has separated is filtered off at the pump and washed with cold water until all the ammonium chloride has been removed. Further purification is effected by recrystallising from hot water with the addition of animal charcoal. The mother liquor is concentrated or treated with absolute alcohol to obtain any leucine remaining dissolved therein. 

In order to purify the latter compound, the crude base is dissolved in the sixfold quantity of absolute alcohol. A five-fold quantity of an absolute alcoholic solution of oxalic acid containing the stoichiometric quantity of oxalic acid (+ 10% excess) to form the monooxalate, is their added. A considerable evolution of heat taking place. Upon cooling of the reaction mixture the monooxalate crystallizes out slowly, in an 80% yield. For purification purposes, the thus-obtained monooxalate is recrystallized from the 17-fold quantity (by volume) of absolute alcohol, with addition of animal charcoal, followed by recrystaillization from the 16-fold quantity (by volume) of a mixture of alcohol and benzene (1 1). The purified monooxalate melts at 160-162°C (decomposition). 

Another case, much more serious and also more pertinent to the chemical process development area, occurred in 1989 when over 1600 people became ill with eosinophilia-myalgia syndrome (EMS) and 38 died, worldwide, after taking l-tryptophan (Trp) manufactured by one producer in Japan. Prior to the outbreak, this producer whose Trp met the >98.5% purity specification had decided to employ a new genetically modified strain of the established Bacillus amyloliquefaciens and also to halve the amount of activated charcoal used in the purification step. These changes cause the Trp product to become contaminated with several new impurities, principally I to III, all associated to some extent (using a crude animal model) with EMS.5... 

Powdered activated carbon (PAC) can be derived from a number of different agricultural commodities, including waste soy hull (32-36). Commercial activated carbon, however, is manufactured from only a few of these, including wood and sawdust, peat, hgnite, nutshells (including coconut shell), and pits (37). Related materials include animal charcoal, gas black, furnace black, lamp black, and activated charcoal, but these are not used in fats and oils purification and will not be further addressed. 

After cooling, the distillate is filtered, the o-nitrophenol washed with water, pressed out on a porous plate, and dried in a desiccator. Since it is obtained completely pure, it is unnecessary to subject it to any further process of purification. In order to obtain the non-volatile p-nitrophenol remaining in the flask, the mixture is cooled by immersion in cold water, the water solution is filtered from the undissolved portions, and the filtrate boiled for a quarter-hour with 20 grammes of animal charcoal, the water evaporating being replaced by a fresh quantity. The charcoal is then filtered off and the filtrate allowed to stand in a cool place over night, upon which the p-nitrophenol separates out in long, almost colourless needles. The oil still present in the distillation flask is boiled with a mixture of 1 part by volume of concentrated... 

Derivation Purification of ozocerite by treatment with concentrated sulfuric acid and filtration through animal charcoal. 

Butyric acid is obtained from the animal charcoal wluch has been used in the purification of glycerin, in which it exists as calcium butyrate. It is also formed by subjecting to fermentation a mixture composed of glucose, water, chalk, and cheese or gluten. The calcium butyrate is decomposed by H,SO, and the butyric acid separated by distillation. 

Bridge s classical procedure287 may be cited as an example of nitrosation of a phenol Phenol (60 g), sodium hydroxide (27 g), and sodium nitrite (54 g) are dissolved in water (1500 ml) and treated gradually with a mixture of concentrated sulfuric acid (150 g) and water (400ml) at 7-8° with cooling. After 2 h the precipitated nitrosophenol is filtered off, washed with ice-water, taken up in ether, and shaken with animal charcoal at room temperature. Evaporation of the ether affords an 80% yield of p-nitrosophenol as yellow needles that melt at 125° with decomposition. For purification it may be recrystallized from benzene or toluene. 

Another early convert was Count Carlo Lodovico Morozzo (Mouroux) (Turin 5 August 1744-2 July 1804), general in the army of Piedmont, who published on the purification of air by plants, the composition of air, the colours of flowers and other vegetables, eudiometry of pure air and air vitiated by animal respiration, the gases obtained from dew, animal colours, the absorption of air by charcoal, and the respiration of oxygen. ... 

The technique for the isolation of nicotinic acid depends on the starting material. In most cases, a preliminary hydrolysis is required either with acids or alkalies. The extractions are more complete if the material is rendered free of lipids, a necessary step when working with animal products. The free acid is extracted from the hydrolysate with organic solvents such as hot alcohol. It may then be separated as such from the organic solvent extract or in the form of an ester or as the copper salt the free acid can be recovered from the copper salt by H2S treatment. Purification is carried out by crystallization from concentrated water or alcohol solutions. Nyc et al. extracted nicotinic acid from the mycelium of Neurospora with acetone. Subsequent purification steps included the formation of the barium salt, acidification with H2SO4 and adsorption of the free nicotinic acid on charcoal. Elution was accomplished with 4% aqueous aniline and the final purification step involves recrystallization from a i 4 mixture of acetic acid and benzene. Leifer et al. have applied paper chromatography with M-butanol saturated with ammonia to separate nicotinic acid from contaminating materials. 

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