100 Kani^as Acadentij of Science. 



solutions of strychnine after treatment of the alkaloid with 

 zinc and hydrochloric acid. 



These methods are valuable as checks on gravimetric separa- 

 tion methods, but of course are of no value where a separation 

 of the alkaloids is desired. 



During the past few months I have been experimenting 

 with a new method for the separation of these alkaloids, which 

 in point of accuracy and simplicity seems to excel any method 

 heretofore published. It is based on the comparative insolu- 

 bility of strychnine chloroplatinate. 



The chloroplatinate of strychnine is nearly insoluble in 

 water, insoluble in alcohol, and practically insoluble in a mix- 

 ture of alcohol 90 per cent and dilute hydrochloric acid 10 

 per cent. The chloioplatinate of quinine is soluble in water, 

 fairly soluble in alcohol, and very readily soluble in the alcohol- 

 hydrochloric acid mixture. It was from those facts that the 

 following method was worked out. 



Dissolve .050 grammes to .100 grammes of the mixed al- 

 kaloids (depending on amount of strychnine present) in a 

 small amount of the alcohol-hydrochloric acid mixture (about 

 5cc.) ; add 20 per cent solution of platinic chloride, drop by 

 drop, while slightly agitating the mixture, until precipitation is 

 complete. Add 5 cc. more of the solvent, cover with watch 

 glass and set aside for one hour, then filter through tared 

 filter, wash with alcohol, place in oven, dry at 100 C. for 

 fifteen minutes, cool and weigh. If the proportion of quinine 

 is large, it will be necessary to add 5 to 15 cc. more of the 

 solvent before filtering. It will also be necessary to decompose 

 the precipitate with alkali (NaOH), recover the strychnine 

 with chloroform, evaporate and reprecipitate the chloroformic 

 residue from a few cc. of the alcohol-hydrochloric acid solvent, 

 with the platinic chloride reagent. 



The chloroplatinate of strychnine is yellow in color, crystal- 

 line, and has a remarkable luster. It contains about 62 per 

 eent of the alkaloid and 18 per cent of metallic platinum. 



The chloroplatinate of quinine has an orange color and an 

 Amorphous appearance. 



A trace of chloroplatinate of quinine gives an amorphous 

 appearance to the chloroplatinate of strychnine — a valuable 

 indication of the purity of the strychnine salt. 



The amount of strychnine can be calculated from the weight 



