THE  AMEEICAN 
JOU 
OF  PHARMACY 
NOTES  ON 
ATION  OF  NITROGLYCERINE. 
By  F.  W.  Heyl  and  J.  F.  Staley. 
After  abandoning  the  older  nitrometer  method  for  the  control 
of  nitroglycerine  in  pharmaceutical  preparations,  it  was  the  practice 
in  this  laboratory  during  a  considerable  period  to  use  in  its  place 
the  modified  Kjeldahl  method  wherever  possible.  The  Kjeldahl 
method  was  found  to  give  results  in  this  instance  fully  as  reliable  as 
in  the  case  of  other  highly  nitrated  organic  substances  such  as 
picrates  and  picrolonates,  which  have  thus  been  successfully 
analyzed. 
Recently  the  latter  method  has  been  supplanted  in  this  laboratory 
by  that  introduced  by  Scoville,1  particularly  when  preparations  bear- 
ing minute  quantities  are  under  examination.  Before  abandoning 
the  Kjeldahl  method  for  the  superior  method  of  Scoville,  we  first 
compared  the  results  obtained  by  using  these  two  methods  in  the 
routine  analysis,  upon  various  samples  of  nitroglycerine  prepara- 
tions. In  view  of  the  comparatively  large  number  of  collaborators 
who  took  part  in  the  cooperative  work  recently  described  2  in  the 
annual  report  of  the  Official  Agricultural  Chemists,  the  results  here 
given  may  be  of  some  interest. 
In  this  valuable  bulletin  the  nitroglycerine  found  by  the  modified 
Scoville  method  is  compared  with  results  obtained  gravimetrically 
upon  the  same  sample  by  extracting  with  anhydrous  ether.  It  was 
the  experience  of  some  of  the  collaborators  that  the  gravimetric 
1Amer.  Jour.  Pharm.,  83,  359,  1911. 
2  Bureau  Chemistry  U.  S.  Dept.  Agric.  Bull.,  162,  214,  1912. 
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