394 
Formaldehyde  and  Cane  Sugar. 
(  Am.  Jour.  Pharm. 
{     August,  1909. 
IS  FORMALDEHYDE  PRODUCED  BY  BOILING  SOLU- 
TIONS OF  CANE  SUGAR?  * 
By  Charles  H.  La  Wall. 
About  a  year  ago  A.  A.  Ramsay  published  a  statement 1  to  the 
eftect  that  when  solutions  of  cane  sugar  are  boiled  without  pressure 
at  from  ioo°  C.  to  103 °  C,  as  would  be  the  case  in  making  jellies 
and  preserves,  formaldehyde  is  produced  in  appreciable  amounts. 
This  paper  was  widely  quoted  and  was  said  to  render  valueless  the 
tests  for  formaldehyde  applied  to  jellies,  preserves,  etc. 
As  this  result  was  contrary  to  observations  made  by  the  writer 
in  the  examination  of  a  large  number  of  samples  of  jellies,  etc.,  all 
of  which  gave  negative  results  when  tested  for  formaldehyde,  it 
was  concluded  to  make  some  further  experiments  with  a  view  to 
ascertaining  the  correctness  of  the  statement. 
Upon  examining  Ramsay's  paper  the  most  striking  point  was  the 
fact  that  the  only  reaction  used  to  detect  formaldehyde  was  the 
well-known  Hehner  milk-sulphuric  acid  test,  which  was  applied  to 
various  fractions  of  the  distillate.  It  is  a  well-known  fact  that  this 
same  Hehner  test  is  a  group  reagent  for  various  aldehydic  bodies, 
and  that  it  is  likely  to  lead  to  erroneous  conclusions  when  unsubstan- 
tiated by  any  other  test  was  shown  in  a  paper  read  by  the  writer 
before  the  Pennsylvania  Pharmaceutical  Association  in  1905,  and 
published  in  several  journals  at  that  time,  to  the  effect  that  vanillin, 
which  is  methylprotocatechuicaldehyde,  gives  positive  results  by 
this  test,  and  that  samples  of  vanilla  ice  cream,  therefore,  will  always 
be  reported  as  containing  formaldehyde  when  examined  for  that 
substance  by  the  Hehner  test  alone. 
At  the  time  that  observation  was  made  it  was  shown  that  the 
most  satisfactory  confirmatory  test  is  the  Rimini  test  with  phenyl- 
hydrazine  hydrochloride  and  sodium  nitroprusside,  followed  by  solu- 
tion of  sodium  hydroxide,  which  produces  a  decided  blue  color  in 
the  presence  of  1  part  of  formaldehyde  in  500,000  of  solution,  and 
which  has  the  additional  advantage  over  the  Hehner  and  other  sul- 
phuric acid  contact  tests  that  there  is  no  danger  of  carbonization 
and  consequent  obscuring  of  the  test  when  applied  to  solutions  con- 
taining sugar. 
*  Read  at  the  April  meeting  of  the  Scientific  Section  of  the  Philadelphia 
Branch  of  the  A.  Ph.  A. 
1  Journ.  and  Proc.  Royal  Soc.  of  New  South  Wales,  41,  172,  abstracted 
in  the  Analyst,  vol.  34,  p.  28. 
