324 
Assay  of  Belladonna  Leaves. 
(Am.  Jour.  Fharm.. 
I       July,  1899. 
quantities  of  moisture  or  extractive.  In  the  following  work  an 
allowance  of  2  grammes  extractive  was  first  made  for  20  grammes 
drug,  hence  98  grammes  solvent  were  used ;  by  making  a  moisture 
determination  and  also  weighing  the  extract  obtained  from  the 
aliquot  portion  of  the  solution,  it  is  possible  to  make  a  correction 
for  the  presence  of  a  different  quantity  of  extractive ;  the  extract 
obtained  under  the  conditions  of  the  assay  process  will  contain 
approximately  15  per  cent,  moisture  and  85  per  cent,  solid  matter. 
By  adding  the  percentages  of  moisture  in  the  leaves  and  of  dry 
extract  and  calculating  to  20  grammes,  there  is  obtained  the  total 
extractive  taken  up  from  the  drug  and  this,  added  to  the  weight  of 
the  solvent  used  in  the  assay,  will  give  the  total  amount  of  solution 
from  which  an  aliquot  part  was  used  to  complete  the  assay. 
From  the  tabular  statement  of  results  it  will  be  noticed  that  the 
extractive  in  the  samples  examined  varied  from  3-5  to  4  5  grammes, 
instead  of  the  2  grammes  first  allowed,  and  the  alkaloid  found  cor. 
rected  for  this  gives  figures  closely  agreeing  with  the  results  of 
the  more  lengthy  total  extraction  processes. 
Based  upon  the  work  as  embodied  in  the  table,  the  following 
shorter  process  is  suggested,  allowing  3-5  grammes  for  extractive: 
Moisture. — Determined  in  2  grammes  leaves  at  ioo°  C. 
Alkaloidal  Assay. — 20  grammes  of  powdered  belladonna  leaves 
are  placed  in  a  glass-stoppered  bottle  of  250  c.c.  capacity  and  96-5 
grammes  solvent  [alcohol  (95  per  cent.),  90  parts ;  water  of  am- 
monia (10  per  cent.),  10  parts]  added ;  agitate  frequently  during  one- 
half  to  one  hour  and  filter  through  a  plaited  filter  (15  cm.  diameter) 
into  a  clean,  dry  flask,  keeping  the  filter  covered  as  much  as  pos- 
sible to  avoid  evaporation.  Weigh  the  flask  with  contents  and 
transfer  solution  to  a  capsule  of  about  150  c.c.  capacity,  in  which  a 
small  glass  rod  has  been  placed,  and  which  have  previously  been 
weighed  ;  weigh  the  emptied  flask  and  note  the  difference  in  the 
two  weights  as  that  of  the  aliquot  portion  for  the  assay.  Evaporate 
on  a  water-bath  at  a  temperature  of  500  C.  until  the  extract,  after 
cooling,  can  no  longer  be  stirred  with  the  glass  rod;  weigh  the  cap- 
sule and  contents,  thus  ascertaining  the  weight  of  the  extract  from 
which  the  percentages  of  extract  and  dry  extractive  can  be  calcu- 
lated [(6)  and  (7)  of  table].  Mix  0-5  c.c.  water  of  ammonia  and  10  c.c. 
water  and  use  this  in  portions  of  1  and  2  c.c.  to  soften  the  extract 
and  transfer  to  the  separator,  and  proceed  according  to  directions 
previously  given  in  this  paper  (page  322). 
