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

In summary, the extraction process used hexanes and acetone as solvents, and the carbon boiling stone residue was filtered out. The oils were then extracted with IR, and the results indicated that there could be organic compounds present.
  • #1
MarcozXD
2
0
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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  • #2
Details?
 
  • #3
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.
 
  • #4
MarcozXD said:
they were evaporated
"They" would be what? Elutions?
This is sounding like a crude extraction rather than a separation process.
 
  • #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.
 
  • #6
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.
 

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

Carbon boiling stones are commonly used in O-chem reactions to prevent the formation of superheated regions within the reaction mixture. This helps to ensure more uniform and efficient heating throughout the reaction. Additionally, carbon boiling stones can also act as nucleation sites for the formation of bubbles, which can help to prevent the reaction from boiling over. Therefore, it is generally recommended to use carbon boiling stones in O-chem reactions.

2. What are carbon boiling stones made of?

Carbon boiling stones are typically made of small, porous pieces of carbon or graphite. These materials are chemically inert and can withstand high temperatures, making them ideal for use in O-chem reactions. They also have a high surface area, which allows for more efficient heat transfer and bubble formation.

3. Are there any disadvantages to using carbon boiling stones?

One potential disadvantage of using carbon boiling stones is the possibility of contamination. If the stones are not properly cleaned or stored, they can introduce impurities into the reaction mixture. Additionally, some reactions may not require the use of boiling stones, and adding them unnecessarily can create more waste and increase costs. It is important to consider the specific reaction and consult with a supervisor before deciding to use carbon boiling stones.

4. Can other materials be used instead of carbon boiling stones?

Yes, there are other types of boiling stones that can be used in O-chem reactions. Some common alternatives include ceramic boiling chips and glass boiling beads. These materials also have high surface areas and can serve the same purpose as carbon boiling stones. However, it is important to check the compatibility of these materials with the specific reaction being performed.

5. How should carbon boiling stones be added to a reaction mixture?

Carbon boiling stones should be added to the reaction mixture before heating. It is important to use a clean, dry spatula or tweezers to handle the stones to avoid contamination. The number of boiling stones added will depend on the size of the reaction vessel and the desired heat distribution. It is generally recommended to add one or two boiling stones per milliliter of reaction mixture, but this can vary depending on the specific reaction and the type of boiling stones being used.

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