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Should carbon boiling stones be used in O-chem reactions?

  1. Jul 28, 2015 #1
    I performed column cromatography on an oil, and used carbon boiling chips but got some weird IR. I used hexanes and acetone as solvents, im trying to figure out some of the spikes, soo im thinking that maybe the boiling stone being carbon could acted as activated carbon and absorbed some organic compounds therefore giving me a weird IR. I could physically see some carbon grains from the boiling stone in my extracted oil.
     
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  3. Jul 28, 2015 #2

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    Details?
     
  4. Jul 29, 2015 #3
    It was spearmint oil, its composed of limonen and carvone. And the column used hexanes for the first three elutions and then 10% acetone in hexanes. Then they were evaporated (there is where we added the carbon boiling stone, there were also clay boiling chips) in order to get rid of the solvents, then I performed GC and IR and got some weird results such as hydroxides in the IR or acetone in GC.
    my best guess is that the sodium pellets from the IR were damaged, but im also exploring other options such as that the carbon stone trapped hexanes or acetone during the evaporation.
     
  5. Jul 29, 2015 #4

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    "They" would be what? Elutions?
    This is sounding like a crude extraction rather than a separation process.
     
  6. Jul 29, 2015 #5
    Yes the elutions were evaporated, I mixed elution one and two to try and get all of the limonene that came out with the hexanes since its the nonpolar compound. My question is just, can carbon boiling stones trap organic compounds (hexane and acetone)?, just like activated carbon can?.
    I saw them dissolve a little, and well organic compounds dissolve in organic solvents.
     
  7. Jul 30, 2015 #6

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    Google this term. You will find that this thread is "The Story On Carbon Boiling Stones." Congratulations --- we've just added an item to the world of "crap" to be found on the internet.

    Charcoal, activated carbon, amorphous carbon, vitreous carbon, fullerenes, schungite, various grades of lamp black, soot, coke, coals, graphite, and other chars ALL exhibit sorptive and catalytic properties, and will leach various "tars" and other residues into any solvent system.

    If you are attempting to assay/estimate yield from your extraction by IR, you will need to filter solids (boiling stone residue) from the extract. Just throwing the whole shebang into the IR is going to give you residue from every cigarette, deodorant stick, air freshener, and incense burner within a square mile of your laboratory, plus whatever manufacturing/coking/activation residues exist in the particular decolorizing/adsorbent grade of charcoal/activated carbon you are using.

    That's the point of using hexanes and acetone to do the extraction; these are sufficiently volatile solvents that they evaporate and leave the oil. Check the grades on both; just "stockroom/slop jar/utility" grades are full of crap.
     
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