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

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Discussion Overview

The discussion revolves around the use of carbon boiling stones in organic chemistry reactions, particularly in the context of column chromatography and the potential for these stones to absorb organic compounds, affecting the results of infrared (IR) and gas chromatography (GC) analyses. Participants explore the implications of using carbon boiling stones in the extraction process of spearmint oil, which contains limonene and carvone.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant notes that the use of carbon boiling chips may have led to unexpected IR results, suggesting that the carbon could act like activated carbon and absorb organic compounds.
  • Another participant questions the clarity of the extraction process, implying that it resembles a crude extraction rather than a refined separation process.
  • A participant expresses concern that carbon boiling stones could trap solvents like hexane and acetone during evaporation, potentially contaminating the results.
  • One contributor emphasizes the sorptive and catalytic properties of various forms of carbon, warning that they may leach residues into solvent systems and affect analytical results.
  • There is a suggestion that filtering solids from the extract is necessary to obtain accurate IR results, as the presence of boiling stone residue could introduce extraneous signals.

Areas of Agreement / Disagreement

Participants express differing views on the impact of carbon boiling stones on the extraction process and analytical results. There is no consensus on whether the use of these stones is advisable or what specific effects they may have on the compounds being analyzed.

Contextual Notes

Participants highlight potential limitations in the extraction process, including the quality of the carbon boiling stones and the possibility of contamination from various sources. The discussion remains open regarding the specific interactions between carbon boiling stones and organic solvents.

MarcozXD
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I performed column cromatography on an oil, and used carbon boiling chips but got some weird IR. I used hexanes and acetone as solvents, I am trying to figure out some of the spikes, soo I am 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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Details?
 
Bystander said:
Details?

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 I am also exploring other options such as that the carbon stone trapped hexanes or acetone during the evaporation.
 
MarcozXD said:
they were evaporated
"They" would be what? Elutions?
This is sounding like a crude extraction rather than a separation process.
 
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.
 
MarcozXD said:
carbon boiling stones
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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