254 POISONS : THEIR EFFECTS AND DETECTION. [§ 313. 
METHODS OF SEPARATION. 
§ 313. General Processes for the Separation of Alkaloidal Substances 
from Organic Matters. —The processes in use are the Stas-Otto process, 
the process of Kippenberger, and that of Dragendorff. The Hilger- 
Kuster method, in which gypsum is used, apparently leads to poor 
results, and will therefore not be described. 
The three processes are seldom used singly, but more or less in com¬ 
bination. The Stas-Otto process consists in exhausting the organic 
matters with strong alcohol. With every kilogramme of such sub¬ 
stances as liver or other internal organs, rather more than a litre of 
alcohol of 92 to 95 per cent, strength is required. The more finely 
divided the organ is the better. For this purpose is is often advisable 
to pass the matters through a mincing machine. The flask containing 
the substances and the alcohol is placed in a water-bath and the cork 
connected with a reflux condenser. The water in the bath is kept at a 
boiling temperature from one to two hours. In the original Stas-Otto 
process an acid, such as tartaric acid, was usually added ; but if the 
substance itself, as is usually the case, has an acid reaction, and at the 
end of the operation the alcohol is found acid, it is preferable not to add 
acid. The alcoholic solution is filtered through a piece of muslin and 
the organic matter pressed in a filter press, so as to squeeze the solution 
out of the mass. It is best now to distil off the alcohol, and then to 
extract the watery fluid in a separating funnel by petroleum ether two 
or three times, otherwise there will be much difficulty in filtration. 
The petroleum ether extract contains all the fatty matter and, it may 
be, some of the alkaloid dissolved in the fat. To recover this the 
petroleum is distilled off, a little paraffin wax added to the fatty matter 
left behind, and the fatty matters washed in a separating funnel with 
hot water made slightly acid by means of hydrochloric acid. 
The original liquid,' free from fat, is then filtered. The clear liquid, 
to which the washings of the fat are added, is now evaporated to dryness 
and treated with absolute alcohol. The absolute alcoholic extract is 
filtered and evaporated to dryness. This contains all the alkaloid in an 
impure state. It is, however, important to note that even when no 
alkaloidal poison is present, the extract invariably contains residues 
which give decided reactions with the group-alkaloidal reagents, such 
as iodine and potassic iodide, phospho-tungstic acid, and so forth. 
Kippenberger’s Process. —In Kippenberger’s process the reaction 
of the final product with general alkaloidal reagents in operating on 
alkaloidal free substances is much less than in the Stas-Otto process. 
Kippenberger extracts the organic substances with glycerin holding 
tannin in solution. To 500 grms. of glycerin should be added about 
100 grms. of tannin. 
