Farmacopeo Nacional Argentina - Sixth Edition 1978
(Translated from Spanish. Reference should be made to the original Spanish version for authenticity.)
Alcohol (Alcohol aethylicum)
(a) | Definition: | Contains not less than 92.3% w/w, or 94.9% v/v (at 15°C) of ethanol. |
(b) | General characteristics: | Colorless, mobile, transparent liquid, with a burning taste and characteristic pleasant odor. Volatile and flammable. Miscible with distilled water in any proportion, without producing turbidity, and miscible with ether, glycerine, chloroform and acetone. |
(c) | Specific gravity: | Not greater than 0.8168 at 15°C. |
(d) | Boiling point: | 78°C |
(e) | Refractive index: | Between 1.3637 and 1.3639, at 20°C. |
(f) | Identification: | (1) To ten drops
of alcohol, add 2 drops of potassium hydroxide solution, and a few drops
of potassium iodide solution until a yellow color appears. Heating the mixture
gently should produce an odor and a precipitate of iodoform. (2) Gently heat 20 drops of alcohol, 20 drops of acetic acid and 10 drops of sulphuric acid. This should produce the characteristic odor of ethyl acetate. |
(g) | Limit of acidity: | To 50 ml of alcohol in a glass-stoppered flask, add 50 ml of distilled water and 5 drops of a solution of phenolphthalein, and then titrate with 0.02 N sodium hydroxide until the red color persists for about 30 seconds. It should not require more than 0.9 ml of the sodium hydroxide solution. |
(h) | Non-volatile matter: | Evaporate 50 ml of alcohol in a tared dish in a water bath and then dry at 100°C. There should not be more than 1 mg of residue. |
(i) | Heavy metals: | To 100 ml of alcohol, add 10 ml of dilute acetic acid, and 10 ml of distilled water. Then evaporate in a water bath until the volume has been reduced to about 20 ml. Subject this residue to the standard F.N.A. test for heavy metals. |
(j) | Fusel-oil components: | Mix 10 ml of alcohol with 5 ml of distilled water and 1 ml of glycerine. Then allow the mixture to evaporate spontaneously on a clear odorless filter paper. There should not be any perceptible foreign odor as the last traces of the mixture evaporate. |
(k) | Amyl alcohol and carbonizable organic residues: | Allow 25 ml of alcohol to evaporate spontaneously from a porcelain dish (protected from dust), until the surface of the dish is just slightly moist. Then, the addition of 2 or 3 drops of sulphuric acid should not produce any red or brown color. |
(l) | Methanol: | Dilute 0.5 ml of alcohol to 10 ml with distilled water; add 2 ml of a fresh solution of potassium permanganate and 15 ml phosphoric acid; then make up to 100 ml with distilled water, and allow to stand for 10 minutes. Then add 2 ml of a 5% solution of oxalic acid in a mixture of equal volumes of distilled water and sulphuric acid. When the solution has been decolorized, take 5 ml and add 2 ml of a 0.3% solution of phenylhydrazine chlorate and 2.5 ml of a 0.5% solution of potassium ferricyanide. Then, after standing for 5 minutes, add 2.5 ml of hydrochloric acid. There should be no red coloration. |
(m) | Aldehydes and organic impurities: | Add 20 ml of alcohol to a thoroughly-cleaned, glass-stoppered cylinder, and cool to about 15°C. Then add 0.1 ml of a 0.1 N potassium permanganate solution, and note the precise time. Then mix by inverting the cylinder, and allow it to stand at 15°C. The red color should not have disappeared completely in under 5 minutes. |
(n) | Acetone, other ketones, isopropanol and tertiary butanol: | Mix 1 ml of alcohol with 4 ml of distilled water, then add 10 ml of an acidified solution of mercuric sulphate and heat in a water bath. It should not produce a precipitate within 3 minutes. |