42 TECHNICAL DRUG STUDIES. 



case they snould be diluted to about the consistency of a 50 per cent 

 sugar solution, and in the latter some method which will separate, 

 the gum and fatty material must be adopted. 



Having obtained a clear solution of the substance in question the 

 procedure is as follows: 



Transfer the solution to a separator and add a slight excess of ammonium hydroxid. 

 (If the product was originally alkaline it is best to acidify it and then add a slight 

 excess of ammonia. If a precipitate is formed it should be separated by filtration 

 and the filtrate used for analysis.) Shake out the solution with 50 cc of Prolius mix- 

 ture (ether 4 parts, chloroform 1 part, and alcohol 1 part), and allow to stand; then 

 collect the clear solvent in another separator and shake out the aqueous solution twice 

 more with the Prolius mixture. Filter the combined solvent solutions through a 

 creased paper into a beaker and evaporate the liquid over a steam bath, using a fan. 

 Do not allow the residue to dry, but as soon as the last portions of alcohol are driven 

 off remove the beaker from the steam. Add 25 cc of normal sulphuric acid in 10 cc 

 portions, warm the mixture slightly and then filter into a separator after each portion 

 of the dilute acid is added, and finally wash with a little water. Then shake out the 

 solution five times with 15 cc portions of chloroform, preserving the chloroformic 

 extracts in another separator. Wash the latter with 10 cc of distilled water, discard 

 the chloroform, and add the wash water to the acid liquid which was shaken out with 

 the chloroform. Then add 10 cc of petroleum ether (boiling at 40-60 C.) and 

 thoroughly shake the separator, separate the acid liquid, and discard the solvent. 

 Add a slight excess of ammonium hydroxid, cool the mixture, and then shake out the 

 solution with 15 cc of petroleum ether of the boiling point before specified and reserve 

 the solvent solution in another separator. Shake twice again with the same quantity 

 of solvent, then wash the combined petroleum ether solutions once with distilled 

 water and filter into a small beaker, washing the separator and filter with 10 cc of 

 petroleum ether. Evaporate the petroleum ether rapidly over a steam bath, using a 

 fan, and if cocain was present in the original material it will be found in the residue. 



By this method it is possible to obtain the cocain in a very pure 

 condition; in fact, it will often crystallize in a few hours even though 

 the amount present be very small. The identification tests are 

 conducted as follows: 



Dissolve the residue in petroleum ether and pour portions of the solvent into a beaker 

 and a small evaporating dish, reserving the remainder for subsequent tests. After 

 the solvent has evaporated dissolve the contents of the beaker in 5 cc of normal sul- 

 phuric acid, warming if necessary, and add potassium mercuric iodid test solution. 



The formation of a precipitate indicates the presence of an alkaloid, 

 but, of course, does not identify it as cocain; if no precipitate occurs 

 further tests are unnecessary. 



To identify the alkaloid treat the contents of the evaporating dish with 2 cc of 

 concentrated nitric acid and evaporate the mixture to dryness over the steam bath. 

 When there is no further odor of nitric acid remove the dish, cool, and add 5 to 10 

 drops of fifth-normal alcoholic potash solution, noting carefully the color and odor 

 of the mixture while the dish is cool and then applying gentle heat and noting the 

 odor again. 



Minute traces of cocain will give off the odor of ethyl benzoate on 

 treatment with nitric acid and alcoholic potash. The odor is very 



