396 
An  Assay  for  Sanguinaria. 
/Am.  Jour.  Pharm. 
\  September,  1913. 
solvents.  Kieselguhr  and  Kaolin  were  tried  for  removing  the 
coloring  matter,  but  were  found  to  retain  considerable  of  the  alka- 
loids. Finally,  Lime  was  found  to  liberate  the  alkaloids,  and,  at 
the  same  time  retain  the  coloring  matter. 
Many  of  the  volatile  solvents,  upon  evaporation,  leave  the  dis- 
solved Sanguinaria  alkaloids  decidedly  colored.  This  is  true  espe- 
cially of  Acetic  Ether  and  Chloroform,  traces  of  these  solvents  being 
apparently  decomposed,  thus  giving  enough  free  acids  to  salify 
a  portion  of  the  alkaloids.  Chloroform  is  evidently  the  best  solvent 
for  the  mixed  alkaloids,  but  cannot  be  used  upon  this  account.  The 
next  best  solvent  seems  to  be  Benzol,  but  it  takes  up  large  quantities 
of  coloring  matter.  The  only  two  solvents  free  from  this  objection 
are  Benzin  and  Ether.  Benzin,  however,  as  shown  by  LaWall 
(Amer.  Jour.  Pharm.,  1896,  p.  305  et  seq.)  dissolves  only  a  part 
of  the  alkaloids.  Ether  dissolves  them  all,  but  is  required  to  be 
used  in  larger  amount  than  Benzol  because  of  its  weaker  solvent 
action.  The  final  solution  of  this  problem  was  the  use  of  Ether 
for  the  first  extraction,  thus  leaving  behind  practically  all  of  the 
coloring  matter,  and  the  use  of  Benzol  for  the  final  extraction, 
thus  giving  a  smaller  bulk  for  evaporation. 
The  greatest  trouble  is  met,  however,  in  trying  to  extract  the 
alkaloids  from  the  ethereal  solutions  by  means  of  acid  solutions. 
The  mineral  acids,  even  in  dilute  solutions,  precipitate  a  large  part 
of  the  alkaloids.  It  has  been  this,  no  doubt,  which  has  rendered 
most  previously  published  assays  uncertain  and  unreliable.  Almost 
in  despair  appeal  was  had  to  nature.  She  furnished  the  key  that 
solved  her  riddle.  The  alkaloids  evidently  existed  in  solution  in 
the  plant.  With  what  natural  acids  were  they  combined  ?  Almost 
thirty  years  ago,  L.  C.  Hopp  (Amer.  Jour.  Pharm.,  1875,  P-  :93 
et  seq.)  demonstrated  by  simple  but  conclusive  tests  that  those  acids 
were  Citric  and  Malic  Acids.  Citric  Acid  was  the  key.  But,  the 
question  arose,  would  not  the  volatile  solvents  extract  some  of  the 
Sodium  Citrate  formed  upon  neutralization  of  the  acid  solutions 
with  Sodium  Hydroxide?  In  order  to  determine  this,  Sodium 
Citrate  was  treated  in  separate  portions  with  Ether  and  Benzol. 
Upon  evaporation  of  the  filtered  solvent  in  a  platinum  basin  no 
weighable  residue  was  left  in  the  case  of  Benzol,  and  only  a  slight 
residue  in  the  case  of  Ether.  Hence,  using  the  two  solvents  in  the 
order  finally  adopted  in  the  perfected  assay,  the  results  were  not 
vitiated  by  the  presence  of  Citrates. 
