DETERMINATION OF NICOTINE IN TOBACfMX 63 



seems to have given satisfactory results in the hands of most analysts, 

 and has come to be recognized as the standard i^rocess. But this 

 method is long and tedious, and hence is not adapted to our needs. 

 It consists essentially in moistening the powdered sample with aque- 

 ous caustic soda and extracting with ether for several hours in a 

 suitable form of continuous extraction apparatus. The ether is care- 

 fully distilled from the extract, and the residue is subjected to distilla- 

 tion with steam. The distillate is collected in 100 c. c. portions and 

 titrated with a standard acid. It is apparent that the process is an 

 expensive one, both in point of materials consumed and necessary 

 equipment and in the time required for carrying it out. 



Keller ° has described a method which is simple and rapid in execu- 

 tion and avoids the tedious process of distilling the extracted nicotine 

 with steam. Six grams of the tobacco, previously dried over lime, 

 are placed in a cylinder with GO grams of ordinary ether and GO 

 grams of petroleum ether, and 10 c. c. of 20 per cent aqueous caustic 

 potash are added. The contents of the cylinder are vigorously 

 shaken for thirty minutes and then allowed to stand for three hours 

 to clarify. The extract is filtered and 100 grams of it placed in a 

 cylinder. To remove the ammonia in solution, a rapid current of 

 air is blown through the extract, after Avhich there are added 10 c, c. 

 of water. After shaking well, an excess of standardized hydrochloric 

 acid is added and the titration completed with standardized ammonia. 

 With some minor modifications the method gives fair approximations, 

 but we have found that it is unsuited to our requirements. In point of 

 materials consumed it is even more expensive than the Kissling proc- 

 ess, and it also contains several sources of error. Adding 10 c. c. of 

 aqueous potash to the ether mixture increases the total weight of 

 solvent more than 8 per cent, and considerable quantities of nicotine 

 remain in the aqueous portion. Ordinary ether boils at 36° C., which 

 is but little above ordinary room temperatures, and consequently it 

 is quite impossible to filter the extract without very considerable loss 

 of the solvent by evaporation. Again, most tobaccos yield extracts 

 which are so deeply colored that the nicotine can not be titrated with 

 accuracy until the solvent has been removed. This is the principal 

 reason why it is necessary to subject the extract obtained by the 

 Kissling process to distillation with steam. From the results of our 

 experiments with Keller's method, supplemented by further tests 

 along other lines, we have developed a process Avhich differs essen- 

 tially from Keller's in all of the details of the operation and. obviates 

 the difficulties encountered in the latter. 



cBer. Pharm. (iesell., 1S98, 145. 

 4359— No. 102—07 5 



