Am.  Jour.  Pharm. 
July,  1921. 
Studies  on  Licorice  Root. 
495 
and  whirled  in  the  centrifuge  for  a  further  10  minutes.  The  liquor 
is  again  discarded  and  the  sediment  is  washed  into  a  weighed  glass 
dish  and  evaporated,  and  the  residue,  dried  in  an  oven  at  100-105°  C. 
for  24  hours,  is  weighed. 
Matters  Insoluble  in  Hot  W ater. 
Two  grams  of  licorice  mass  are  placed  in  a  100  cc.  centrifuge 
tube,  which  is  nearly  filled  with  hot  water.  This  is  kept  hot  on  a 
suitable  bath  and  stirred  at  intervals  until  all  soluble  matter  is  in 
solution.  The  further  operation  is  carried  out  as  under  "Matters  in- 
soluble in  cold  water,"  using  hot  water  throughout. 
Sugars  are  determined  in  the  filtrate  from  the  glycyrrhizin  de- 
termination, or  preferably  on  an  original  portion  of  the  licorice  ex- 
tract, using  neutral  lead  acetate  to  clarify,  and  following  directions  of 
the  Association  of  Official  Agricultural  Chemists. 
SUMMARY. 
1.  The  method  of  Linz  for  the  determination  of  glycyrrhizin  in 
licorice  extract  is  discussed. 
2.  A  method  is  given  for  the  determination  of  glycyrrhizin  in 
licorice  extract. 
3.  Comparative  experiments  have  been  made  on  various  meth- 
ods for  separating  part  or  all  of  the  resins  and  bitter  principles  from 
licorice  root,  before  proceeding  to  the  determination  of  glycyrrhizin. 
4.  A  method  is  given  for  the  determination  of  glycyrrhizin  in 
licorice  root,  involving  removal  of  resins  with  ether,  followed  by  ex- 
traction of  glycyrrhizin  with  75  per  cent,  alcohol. 
5.  The  figures  for  glycyrrhizin  in  licorice  root,  published  by 
other  investigators,  and  in  books,  are  too  low. 
6.  The  other  constituents  of  licorice  extract  and  root,  which 
may  be  advantageously  included  in  an  analysis,  are  mentioned. 
I  have  been  very  ably  assisted  in  this  work  by  Messrs.  Bertrand 
Schneeberg  and  Milton  Hartman,  and  express  my  thanks  to  them, 
as  well  as  to  the  MacAndrews  &  Forbes  Company,  which  has  gen- 
erously encouraged  the  work. 
Laboratory  of  the  MacAndrews  &  Forbes  Company, 
Camden,  New  Jersey. 
June  17,  1921. 
