Wash / Re-X?

[thrillho93]

Hi,

I have some dry spice that I’d like to wash. I know that crystals can be water soluble, so I plan on dissolving them into Naptha and washing them with sodium carbonate + water.

Then I wanted to re-x them in Heptane. Is it possible to wash them with heptane and “combine” both steps?

 

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Freebase DMT solubility in water is negligible. When you wash DMT with sodium carbonate + water, the pinch of sodium carbonate is added to ensure DMT does not dissolve into the water. The sodium carb wash only removes polar impurities, like drops of lye soup. You can't move DMT from naphtha to sodium carbonate water to heptane. Sorry if you already understood that.

If you want to re-x with heptane, just skip the naphtha and dissolve DMT straight into heptane, then do the sodium carbonate wash on the heptane solution, followed by your re-x.

Or if you're asking about washing the DMT with heptane, you'd want to do that while it's dissolved an in immiscible solvent (water). You could do a mini-A/B (acid/base), which starts with dissolving your DMT in acidic water. From there you could wash the aqueous DMT-salt solution with heptane, picking up any non-polar impurities, like maybe naphtha residues. Then you separate and discard the heptane wash, add your base, and pull with fresh heptane. Now you're back where you could do the sodium carbonate wash on the heptane solution to pick up any polar impurities, followed by precipitation.

 

[froggydays]

I thought to purify you add the powder dmt after scraping to warm heptane after which fatty or other residues should fall to the bottom of the beaker, right? And then FP the heptane solution again.

 

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I thought to purify you add the powder dmt after scraping to warm heptane after which fatty or other residues should fall to the bottom of the beaker, right? And then FP the heptane solution again.

That’s a simple re-x. There’s several additional purification techniques that can be done before a re-x.

 

[thrillho93]

And correct me if I’m wrong but a re-x won’t always remove impurities like lye right?

 

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For lye, re-x isn't a targeted removal like a water + sodium carbonate wash is.

But if you dissolve lye-contaminated DMT into heptane, the lye wouldn't dissolve and would get left at the bottom of the glass. If you carefully pour or pipette the heptane solution away from whatever is visibly on the bottom, you might successfully leave behind polar impurities like lye.

But most of the time you'd have such a small amount of lye to remove, if any, so it would be like trying to separate dust from a glass of water -- it's likely to be invisibly small or suspended particles that move with the liquid. I'd recommend the water wash for a more definitive separation.