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Chiral Purity (enantiomer excess) for HPLC

  1. Nov 8, 2007 #1
    [SOLVED] Chiral Purity (enantiomer excess) for HPLC


    When I use HPLC to test Chiral Purity, obtain chromatogra and peak area. How do I calculate with Peak area?

  2. jcsd
  3. Nov 8, 2007 #2
    LOL you want to know how they used to do it back in the day? Weigh the piece of paper your spectrum is on. Cut out the peaks and weigh the paper. You should be able to tell by the difference in mass how pure your compound is.
  4. Nov 9, 2007 #3


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    If you are given the areas of both enantiomers (or even epimers), the ee is calculated by first summing the areas of both peaks and determining their relative ratios. R and S, for example where R+S=1 and ratio of R=R/(R+S). ee is defined as {(R-S)/(R+S)}*100. If the areas are 0.6:0.4, the ee is 20%. If the areas are 0.98:0.02, the ee would be 0.96. In this example the desired enantiomer is R. If it is S in your case, just switch it around. If you get a negative number, the reaction produces an ee of the undesired product.
  5. Nov 12, 2007 #4
    Thanks gravenewworld and chemisttree.
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