316 
Citrate  of  Iron  and  Quinine. 
Km.  .lour.  Pharm. 
June,  1S84. 
THE  ASSAY  OF  CITRATE  OF  IRON  AND  QUININE. 
By  John  Chales  Falk,  Ph.G. 
From  an  Inaugural  Essay. 
The  Pharmacopoeia  gives  a  process  for  assaying  this  salt  which  con- 
sists in  precipitating  the  quinine  with  solution  of  soda  from  an  aqueous 
solution  of  the  scales,  dissolving  out  the  quinine  with  chloroform, 
separating  the  chloroform  and  evaporating  to  dryness.  The  weight  of 
the  residue  is  given  as  the  proportion  of  quinine  in  the  scales.  In 
order  to  test  the  correctness  of  this  process  I  first  prepared  some  citrate 
of  iron  and  quinine,  carefully  following  the  pharmacopoeial  proportions 
and  directions,  and  then  assayed  it  as  follows : 
Dissolve  4  Gm.  of  the  salt  in  30Ccm.  of  water,  pour  into  the 
separator,  add  the  rinsings  of  the  capsule  and  0*5  Gm.  of  tartaric 
acid,  solution  of  soda  in  excess,  then  add  successive  portions  of  chloro- 
form, and  shake  several  minutes  after  each  addition.  Having  allowed 
four  portions  each  of  loCcm.  to  run  into  a  weighed  beaker  it  was 
evaporated  on  the  water-bath  till  of  a  constant  weight,  which  was  *560 
Gm.  A  fifth  portion  of  chloroform,  evaporated  separately,  left  a  resi- 
due weighing  *004  Gm.  showing  that  practically  all  the  quinine  was  re- 
moved from  the  solution.  This  gave  then  a  total  residue  weighing 
'564  Gm.  or  *084  Gm.  more  than  the  amount  of  quinine  in  the  4 
Gm.  of  scales.  On  repeating  the  assay  the  same  result  was  obtained, 
and  obviously  this  process  was  not  to  be  depended  upon  for  accurate 
results. 
This  residue  was  dissolved  in  a  small  amount  of  water  with  sul- 
phuric acid,  filtered  and  the  filter  washed  with  acidulated  water  till  the 
filtrate  ceased  to  be  affected  by  solution  of  soda.  The  filtered  solu- 
tion was  then  treated  with  an  excess  of  solution  of  soda,  the  precipi- 
tate collected  on  two  balanced  filters  and  washed  with  cold  distilled 
water  till  the  washings  ceased  to  cloud  with  solution  of  chloride  of 
barium.  The  filtrate  and  washings  measured  65Ccm.  The  filters 
and  contents  were  dried  on  the  water  bath  till  they  ceased  to  lose 
weight.  The  weight  of  quinine  thus  obtained  was  '477  Gm.  equal 
to  11*925  per  cent.,  and  it  was  almost  pure  white.  The  correctness  of 
this  result  was  verified  by  repeating  the  assay  with  the  same  scales. 
Six  samples  of  the  salt  were  procured  in  Philadelphia  and  assayed 
for  total  alkaloids  only,  in  precisely  the  same  manner. 
