YEAR-BOOK OF PHARMACY PART I CHEMISTRY Absinthe, Detection of, in Liqueurs. X. Rocques. (Annales de Chim. analyt., 13, 227.) Two hundred c.c. of the liqueur is treated with 20 c.c. of water and distilled with a little pumice stone, until 200 c.c. have distilled over. To this 1 c.c. of pure aniline and 1 c.c. of H,PO1, sp. gr. 1.750, are added, and the mixture is warmed for an hour under a reflux condenser. On cooling, 20 c.c. of water is added, and the mixture is again distilled until 200 c.c. have been collected. The distillate is then treated, in a capacious separator, with 120 c.c. of ether, and, after mixing, with 400 c.c. of water. After agitation, the ethereal layer which separates should measure about 50 c.c.; the aqueous portion is then run off and rejected, and the ether solution is transferred to a flat-bottom capsule; 10 c.c. of alcohol, 95 per cent., is added, and the whole is left exposed at the ordinary temperature overnight. The residue, which should measure about 5 c.c., is then tested as follows. One c.c. of fresh sodium nitroprusside solution and 0.5 c.c. of 10 per cent. NaOH solution are added and left in contact for 30 seconds; then 1 c.c. of glacial acetic acid is added. On agitation a fugitive red colour is produced in the presence of wormwood oil or of any oil containing thujone. Some oils, such as anise and star-anise, which do not react as above, give a yellow tint on adding the alkali; and with anise a slight greenish shade is apparent with the glacial acid. It is claimed that this reaction will detect 0.005 Gm. of thujone in 200 c.c. of alcohol 50 per cent. (See also Year Book, 1907, 3, 178.) Acetanilide, Method for Determining in "Headache Powders." A. Siedell. (Journ. Amer. Chem. Soc., 29, 1088.) The acetanilide present is saponified, and the aniline liberated determined with standard potassium bromate solution. The standard potassium bromate solution may be conveniently prepared by adding bromine to a cold, almost saturated, aqueous solution of about 100 Gms. of potassium hydroxide, until no more is taken up, diluting somewhat with water, and heating to expel the excess of bromine, filtering and bringing to a volume of about 2 litres. The solution may be standardized with weighed amounts of either pure aniline or acetanilide. In the latter case, the acetanilide is first boiled several minutes in a moderately concentrated solution of hydrochloric acid and the hot solution titrated. The bromate solution is diluted so that each c.c. corresponds to 0.01 Gm. acetanilide. Experiments made for the purpose of ascertaining the limits of strength of acid and time of heating necessary for complete saponification of acetanilide showed that the acid solution should contain not less than 20 per cent. concentrated HCl, and the heating should be continued for at least an hour on the steam-bath, or the solution boiled energetically for 5 minutes. In these experiments 0.5 Gm. samples of acetanilide and approximately 60 c.c. of the acid solution were used. The results obtained were about 1 per cent. below the amount of acetanilide present. The presence of caffeine, in the quantities used for medicinal purposes, does not interfere with the results. Sugar, becoming caramelized by boiling with acid, produces a dark colour, which must be removed with animal charcoal, or the acetanilide may be removed from the mixture by means of CHCI, before saponification. The presence of salol has no effect on the process, but that of antipyrine or of phenacetin renders it inapplicable. Acetanilide, Phenacetin, Caffeine and Salol, Solubilities of, in various solvents. J. Seidell. (Journ. Amer. Chem. Soc., 29, 1088.) The solubilities of these substances, as shown in the following table, were determined with a view to their extraction and separation in "headache powders." Thus, mixtures containing salol, caffeine and acetanilide can be separated fairly well by digesting first in toluene to remove the salol, and then in amyl alcohol to remove the acetanilide; there is no solvent which affords a good separation of acetanilide from phenacetin. Acetone, Sensitive Test for, in Ether or Alcohol. H. Wester. (Pharm. Zentralh., 48, 620.) Three c.c. of the ether to be examined is shaken up with 5 per cent. aqueous solution of hydroxylamine hydrochloride and then with 4 c.c. of NaClO solution. In the presence of as little as 0.028 per cent. of acetone, the separating ether layer shows a distinct blue or greenish tint. Excess of the NaClO solution should be avoided. Acetyl-Salicylic Acid. (Evans' Analyt. Report, 1908, 5.) The melting point of eight samples (undried) ranged from 131° to 135°C., and of three from 121° to 124°C. A specimen which was said to cause vomiting, melted at 133°C., so that, as merely traces of free salicylic acid could be detected and the identification tests were normal, the trouble was only to be accounted for by the personal idiosyncrasy of the patient. Achillea millefolium, Essential Oil of. (Pharm. Review, 25, 215.) The fresh herb, cut in the morning, distilled the next day, yielded 0-234 per cent. of a deep blue oil, sp. gr. 0-876; saponification value, 37-7; acetyl value, 74. The entire plant distilled after drying gave 0-237 per cent. |