THE  AMEEICAX 
JOURNAL  OF  PHARMACY 
NOVEMBER,  1908 
THE  DETERMINATION  OF  CHLOROFORM  IX 
LOZENGES. 
By  Edwin  Dowzard. 
As  it  cannot  be  expected  that  the  full  amount  of  chloroform 
incorporated  in  a  lozenge  mass  will  be  retained  in  the  finished 
product,  it  was  considered  a  matter  of  sufficient  interest  to  deter- 
mine, if  possible,  the  actual  amount  of  chloroform  present. 
After  some  preliminary  work  a  satisfactory  method  was  worked 
out  based  on  that  of  Xicloux  (Comptes  Rendus,  1906,  142,  163) 
for  the  determination  of  traces  of  chloroform  in  alcoholic  solutions 
and  air. 
Chloroform  when  present  in  alcoholic  solution  in  a  quantity  not 
exceeding  0.1  Gm.  can  be  determined  by  boiling  in  a  flask  under 
a  vertical  condenser  with  an  alcoholic  solution  of  potassium 
hydroxide.  After  cooling,  the  liquid  is  neutralized  and  the  chlorine 
determined  by  titration  with  standard  silver  nitrate  solution. 
In  the  method  about  to  be  described  the  following  reagents  are 
required : 
1.  Alcoholic  Solution  of  Sodium  or  Potassium  Hydroxide.  (25 
Gm.  of  pure  NaOH  or  KOH  are  dissolved  in  1000  c.c.  of  75  per 
cent,  alcohol.) 
2.  Dilute  Xitric  Acid.  (200  c.c.  of  nitric  acid,  S.  G.  1.42.  are 
diluted  to  1000  c.c.  with  distilled  water.) 
3.  Calcium  Carbonate,  free  from  chlorides. 
4.  Phenolphthalein  Solution,  U.  S.  P. 
