Manual of practical pharmaceutical chemistry / by George Robertson.

  • Robertson, George
Date:
[1889]
Catalogue details

Licence: Public Domain Mark

Credit: Manual of practical pharmaceutical chemistry / by George Robertson. Source: Wellcome Collection.

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    6 For Total Alkaloids : To the mother-liquid, from the preceding process, add solution of ammonia in slight excess. Collect, wash, and dry the precipitate, which will contain the other alkaloids. Divide the weight of this precipitate by 2, and add it to the percentage weight of the quinine and cinchonidine. This gives the percentage of total alkaloids. Cinchona Bark {Extraction of Total Alkaloids). ANOTHER PROCESS. Take of Cinchona Bark (fine powder) Slaked Lime Chloroform Diluted Sulphuric Acid ] Distilled Water ) Rub the slaked lime and four ounces of water to a smooth cream in a mortar, and make it into a paste with the po\Vdered cinchona bark {note i). Dry the mixture over a water bath {note 2). Powder the mass and place it in a cylindrical percolator. Pour in 3^ fluid ounces of chloroform. Let it stand until packing is complete, then percolate slowly. After a time pour 3^- fluid ounces more chloroform into the percolator. When the percolation is complete, transfer the percolate to a stoppered glass retort {note 3). Add nearly ^ fluid ounce of water, and sufficient diluted sulphuric acid to render the mixture acid to test paper. Distil off the chloroform and preserve. Allow the residue in the retort to cool, then filter it {note 4). To the filtrate, add solution of ammonia in slight excess. Collect the precipitated alkaloids upon a filter, wash and dry over sulphuric acid, under a bell glass. Notes on the process:— 1. The lime liberates the alkaloids from their natural salts (the kinates). 2. The chloroform will then dissolve out the free alkaloids. 3. The chloroform dissolves out the quinine, cinchonine, quinidine and cinchonidine. 4. The dilute acid and water retain the mixed alkaloids as acid sulphates. 5. The best Red Bark should yield from 5 to 6 % of total alkaloids, not less than half being quinine and cinchonidine. 750 grains. 400 grains. 7 fluid ounces.
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