404 
Analysis  of  JTusfai'd. 
j  Am.  Jour.  Pharm,. 
(    August,  18S-2. 
A  METHOD  FOR  THE  ANALYSIS  OF  MUSTARD; 
By  Albert  R.  Leeds  and  Ed(iar  Ev^erhart. 
So  far  as  is  known,  there  has  been  only  one  attempt  made  to  ana- 
lyze mustard  by  its  separate  constituents.  Hassall,  in  his  book  on 
Food,  its  Adulterations  and  the  Method  for  their  Dete(;tion,  proposes 
an  analysis,  partly  direct  and  partly  indirect.  His  method,  and  the 
results  obtained  by  it,  are  those  most  quoted  both  in  English  and  for- 
eign books  and  journals. 
His  plan  of  analysis  is  as  follows :  The  moisture  and  ash  are  deter- 
mined as  ordinarily,  and  the  oil  by  extracting  with  ether.  The  myro- 
nate  of  potash  is  estimated  by  taking  advantage  of  its  well-known 
reaction  with  the  myrosine  contained  in  the  mustard  flour,  in  presence 
of  water.  Forty  or  fifty  grains  of  the  mustard  are  allowed  to  digest 
for  twenty-four  hours,  with  about  250  cc.  of  water  in  a  well-corked 
flask.  At  the  end  of  that  time  all  the  myronate  of  potash  will  have 
been  decomposed  by  the  ferment  myrosine  into  glucose,  sulphate  of 
potash  and  mustard  oil  (allylthiocarbamide),  according  to  the  equation 
C\oHi8KNS20,,==C6Hip6-f-KHS04-fC4H5NS.  The  contents  of  the 
flask  are  distilled,  and  all  of  the  allylthiocarbamide  goes  over  with  the 
water  vapor.  The  end  of  the  condenser  dips  below  the  surface  of 
some  strong  ammonia  water  to  prevent  loss  of  the  volatile  oil.  When 
no  more  oily  drops  come  over  with  the  distillate,  the  receiver  and  its 
contents  are  removed  and  allowed  to  stand  until  the  allylthiocarbamide 
has  combined  with  the  ammonia,  forming  thiosinnamine  (C4H.NS.NH3). 
The  solution  is  evaporated  to  dryness  in  a  tared  platinum  dish,  and 
from  the  amount  of  thiosinnamine  found  is  calculated  the  myronate 
of  potash. 
So  far  the  method  is  all  that  can  be  desired,  but  the  remaining  part 
is  open  to  very  serious  objections.  For  the  determination  of  the  myro- 
sine and  sulphocyanide  of  sinapine,  a  combustion  of  the  mustard  is 
made  with  soda-lime  for  the  total  nitrogen,  and  another  portion  is  fused 
with  alkaline  carbonates  and  nitrates,  to  estimate  the  total  sulphur. 
As  much  nitrogen  and  sulphur  as  is  contained  in  the  myronate  of  pot- 
ash is  subtracted  from  the  total  nitrogen  and  sulphur,  and  fronr  the 
two  residues  are  calculated  the  amounts  of  myrosine  and  sulphocya- 
nide of  sinapine.    The  cellulose  is  estimated  by  diflerence. 
The  whole  of  the  sulphur  residue,  and  so  much  of  the  nitrogen  as 
is  necessary,  are  calculated  into  sulphocyanide  of  sinapine,.  and  the 
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