486 
Studies  on  Licorice  Root. 
5  Am.  Jour.  Pharm. 
\      July,  1921. 
tated  glycyrrhizin  is  dissolved  in  io  cc.  warm  95  per  cent,  alcohol. 
Both  portions  of  dissolved  glycyrrhizin  are  then  filtered  through  a 
70  mm.  No.  40  Whatman  paper  into  a  weighed  glass  dish.  The 
tubes  and  paper  are  washed  with  warm  95  per  cent,  alcohol  and  the 
washings  added  to  the  dish.  Two  drops  of  5  per  cent,  ammonia  are 
added  to  neutralize  any  traces  of  sulphuric  acid.  The  solution  in  the 
dish  is  then  evaporated  to  dryness  and  the  glycyrrhizin  weighed, 
after  drying  at  ico°  C.  overnight. 
The  glycyrrhizin  weighed  is  fairly  pure  and  there  seems  no  prac- 
ticable method  of  purifying  it  further,  at  any  rate  for  technical- 
analytical  purposes. 
DETERMINATION  OF  GLYCYRRHIZIN  IN  LICORICE  ROOT. 
The  matter  of  determining  glycyrrhizin  in  root  is  a  little  dif- 
ferent from  that  of  the  determination  in  extract. 
In  the  latter  case,  the  root  has  been  subjected  to  an  aqueous  ex- 
traction in  the  factory,  and  most  of  the  resins  and  some  of  the  bitter 
principles  have  remained  behind  in  the  spent  root,  and  do  not  there- 
fore enter  into  analytical  consideration  to  any  great  extent. 
The  process  of  manufacture  has  effected  a  partial  separation. 
In  the  case  of  determining  glycyrrhizin  in  root,  all  of  the  constitu- 
ents of  the  root  must  be  reckoned  with. 
It  has  been  suggested  by  some  investigators  that  the  root  should 
be  extracted  with  water,  parallel  to  factory  procedure  in  making 
licorice  extract,  the  solution  separated  from  the  "spent  root,"  evap- 
orated and  precipitated  with  sulphuric  acid. 
Linz  has  clearly  pointed  out  the  objections  to  such  a  procedure, 
which  are,  firstly,  mechanical  difficulties  (powdered  root  is  difficult 
to  percolate  with  water  and  a  solution  is  obtained  which  will  not  fil- 
ter satisfactorily),  and,  secondly,  a  very  impure  glycyrrhizin  is  ob- 
tained. 
I  am  therefore  convinced  that  it  is  highly  desirable  to  remove 
starch  and  gums  by  means  of  alcohol,  because  a  clean  liquid  is  ob- 
tained for  manipulation,  and  a  purer  glycyrrhizin  is  weighed. 
The  glycyrrhizin  is  very  conveniently  removed  from  the  root 
by  means  of  dilute  (75  per  cent,  by  volume)  alcohol,  but  this  strength 
alcohol  also  removes  from  the  root  some  resins  and  bitter  prin- 
ciples, which  may  contaminate  the  glycyrrhizin  weighed,  to  a  greater 
or  less  extent.    It  is  therefore  necessary  to  consider  preliminary  re- 
