Am.  Jour.  Phartn. ') 
April,  1894.  / 
Presence  of  Lead  in  Citrates. 
177 
Citrate  of  potassium,  obtained  from  four  different  sources,  was 
examined, 
In  the  8  samples  obtained  from  one  house,  3  showed  the  presence 
of  metallic  lead,  while  all  reacted  for  lead  when  examined  in  solu- 
tion. 
From  another  source  5  samples  were  obtained,  two  of  which  showed 
a  grayish  deposit  on  solution,  three  the  presence  in  a  soluble  form, 
while  two  were  free  from  the  same. 
From  a  third  source  two  samples  were  examined,  both  containing 
lead  in  a  soluble  form. 
A  fourth  source  furnished  one  sample,  which  was  perfectly  pure. 
It  may  be  seen  from  this  result  that  the  impurity  is  rather  com- 
mon. 
Lithium  Citrate. — It  appears  singular,  that  neither  the  Pharmaco- 
poeia of  1880  or  the  recently  issued  1890  edition  recognizes  the  possi- 
bility of  the  presence  of  this  dangerous  contamination,  while  in  the 
case  of  lithium  citrate  complete  tests  are  given  for  the  detection  of 
lead  and  similar  metallic  impurities. 
Of  this  salt  three  samples  were  examined,  two  of  home,  one  of 
foreign  manufacture,  none  of  which  revealed  the  presence  of  lead. 
It  appears,  probably  due  to  the  requirements  of  the  Pharmacopoeia 
as  to  the  purity  of  the  salt,  that  the  manufacturers  observe  greater 
care  in  its  preparation. 
To  determine  if  this  citrate  also  acted  upon  metallic  lead,  some 
particles  were  left  in  contact  with  an  aqueous  solution  of  the  salt. 
The  presence  of  lead  in  the  solution  could  -  readily  be  detected 
after  3  or  4  hor  1  s  standing. 
Other  Citrate  — A  sample  of  ammonium  citrate  was  also  examined, 
which  showed  ead  to  be  present.  As  ammonium  salts  readily 
attack  the  metal,  the  cause  of  this  presence  is  obvious. 
Sodium  citrate,  not  being  in  frequent  use,  was  not  examined. 
Of  alkaloidal  citrates  the  caffeine  salt  is  the  most  important. 
Several  samples  of  this  were  examined,  all  being  perfectly  free 
from  any  metallic  impurity. 
This  comprises  the  most  important  citrates  of  commerce,  with  the 
exception  of  the  scaled  iron  citrates,  which  were  not  examined. 
Official  Solutions  of  Citrates.- — The  presence  of  lead  is  not  confined 
to  commercial  citrates  alone,  but  official  solutions,  usually  prepared 
extemporaneously  by  the  pharmacist,  are  liable  to  be  subject  to  the 
