- 9 - 
ml. of water, and titrate with a 0*1 N alkali (phenolphthalein in- 
dicator), adding 5 ml* of toluene toward the end of titration* The 
amount of 0*1 N sodium hydroxide used aultiplied by 0,0081 gives the 
oontent of nicotine. The method is based on the fact that nitrous 
acid, without affecting the nicotine, transforms the anabasine into 
the nitroso compound, which is not precipitated by picrio acid under 
the above conditions.-- Shmuk and Borozdina (65). 
Nicotine and anabasine, treated with an aqueous solution of 
aniline and a 5-peroent solution of ammonium thiocyanate or potassium 
thiooyanate in bromine water, give a yellow color, whioh remains 
constant after the addition of 0.5 to 3.0 cc. of 5 to 10 percent 
sodium carbonate for nicotine, and ohanges to a bright rose for 
anabasiae. The colored solutions can be compared in the colorimeter 
with corresponding standard solutions. However, the determination 
of anabasine and nicotine by the coloriraetric method in plants was 
complicated by the other compounds containing the pyridine ring.— 
Shmuk and Borozdina (66). 
To identify the alkaloids of to v acco the picrates of nornico- 
tine and anabasine can be methylated quantitatively by her ting with 
formaldehyde-formia aoid. Picrio acid does not methyl ate under the 
conditions used. Determination of the melting point of the piorate 
before and after methylation enabled nornicotine to be identified in 
the presence of nicotine.— Shmuk (64 ). 
Nicotine forms an azeotropio mixture with water in a concentra- 
tion of 2.5 gnu per 100 ml. This property is used in separating it 
from nomiootine or anabasine, or both. The separation of nicotine 
from a mixture of the three alkaloids was 97 to 103 peroent of theory 
when the procedure consisted in distilling the mixed alkaloids from 
126 ml* of water solution through the Widmer oolumn to a low volume 
(about 15 ml.), adding 60 ml. of water oontaining 2 gnu of sodium 
ohloride, and continuing again to a volume of 15 ml. The combined 
distillate was titrated and calculated as nicotine, but represents 
all the nicotine with some of the accompanying alkaloid or alkaloids. 
The titrated distillate was made alkaline with a slight excess of 
standard alkali to neutralize the standard acid, and the dis- 
tillations were repeated as before but without the addition of 
sodium chloride. The oombined distillate was titrated and the 
niootine calculated.-- C. K. Smith (73). 
The determination of niootine and nornicotine in the presenoe 
of each other in aqueous solution is described. One portion of the 
solution is treated with sodium nitrite and acetic acid. The nitroso- 
nornicotine formed is not volatile in steam from a solution buffered 
at pH 10. The unchanged niootine is steam-distilled off, and 
determined by acidimetrio titration or "By precipitation with 
siliootungstic aoid. To another portion formaldehyde and formic 
aoid are added to methylate the nomiootine to niootine. The total 
alkaloid, now niootine, is distilled off after addition of excess 
sodium hydroxide and determined as before. The difference between 
the two values represents the nomiootine. Details were developed 
-for attaining an accuracy of 97 to 98 percent.— Markwood (46). 
