Chromatography - Chem 131A Paper Partition Chromatography Introduction Chro m at o gr a p h y is a simpl e and rapid m eth od forthe se p aration

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Chem 131A: Paper Partition Chromatography Introduction:   Chromatography  is a  simple  and  rapid  method  for the  separation  of a  mixture  of compoun   solution  and  a  sensitive  method  for identification  of each  compound.   One  or  the  basic  principles  under   chromatography  technique s  is the  very  rapid  partitioning  of the  various  compounds  (solutes)  between     different  immiscible  phase s:  a   stationary  phase  and  a  mobile  phase. For this  paper  chromatography  exercise,  the  developing  or  irrigating  solvent  consists  of a  homog e n e o u   of ethyl  acetate,  formic  acid,  and  water  in a  definite  proportion  (7:2:1).   Ethyl acetate  and  water  are   immiscible  with each  other  but the  addition  of formic  acid  allows  the  two liquids  to beco m e  mutually  sol   within limits.   The  chromatography  paper  is manufactured  from  nearly  pure  cellulose  fibers.   Cellulose     polysaccharide  of glucos e.   Other  solvent  system s  such  as  80%  phenol/20%  water  are  also  excellent  f   acids. When  the  chromatography  paper  com e s  into  contact  with the  irrigating  solvent,  the  water  molecules  wi   beco m e  attracted  to the  cellulose  molecule s.   Why?   This  combination  of cellulose  and  water  is called     stationary phase.   The  remainder  of the  irrigating  solvent  (not the  water)  is the   mobile  phase.   The   compon ents  that are  to be  separated  and  identified  will partition  rapidly  between  the  two phase s.   Com   that are  more  nonpolar  will tend  to be  more  "soluble"  in the  nonpolar  mobile  phase. Solutions  containing  the  compound s  to be  separate  are  applied  near  one  edg e  of the  paper  and  allowe
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This note was uploaded on 09/08/2010 for the course CHEM 132L at San Jose State University .

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Chromatography - Chem 131A Paper Partition Chromatography Introduction Chro m at o gr a p h y is a simpl e and rapid m eth od forthe se p aration

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