THE  AMERICAN 
JOURNAL  OF  PHARMACY 
JUNE,  i9io% 
SUGGESTED  U.S. P.  TESTS  FOR  GLYCERIN. 
By  Thomas  M.  Starkie,  Manager,  William  F.  Jobbins,  Incorporated. 
The  Food  and  Drugs  Act  having  adopted  the  Pharmacopoeia 
as  the  standard  by  which  manufacturers  must  be  governed,  it  is 
desirable  and  necessary  that  the  Pharmacopoeia  requirements  should 
specify  such  definite,  fixed  limits  of  impurities,  and  tests  for  deter- 
mination thereof,  as  will  avoid  the  possibility  of  contention  between 
pharmacists  and  chemists,  and  in  the  commercial  world,  and  the 
attention  of  the  members  of  the  Committee  of  Revision,  meeting 
in  Washington  this  month,  is  invited  to  the  subject  of  Glycerin. 
Many  of  the  tests  set  forth  in  the  Pharmacopoeia,  official  at 
the  present  time,  are  indefinite  and  unreliable,  and  allow  of  so 
much  possibility  of  contention,  particularly  by  some  pedantic  analyst, 
that  any  glycerin  could  be  claimed  as  failing  to  meet  the  require- 
ments of  the  Pharmacopoeia.  It  has  been  contended  that  in  a 
general  way  the  tests  as  given  in  the  present  Pharmacopoeia  will, 
in  the  hands  of  an  intelligent  analyst,  enable  him  to  distinguish 
between  a  pure  and  an  impure  glycerin.  Experience  over  a  great 
many  years  in  the  glycerin  business  has  shown  that  even  the 
most  intelligent  and  careful  analysts  will  differ  regarding  the  Phar- 
macopoeia tests  for  glycerin. 
Tests  involving  mixing  with  concentrated  sulphuric  acid,  and 
heating  glycerin  with  sulphuric  acid  and  alcohol,  should  be  aban- 
doned, inasmuch  as  they  lead  to  varying  results  in  different  hands, 
and  even  when  carried  out  with  the  greatest  care  may  lead  to 
wrong  conclusions,  and,  also,  such  tests  show  no  more  than  can 
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