metalresearcher
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Is potassium 40 ever isolated ?
This isotope, occurring only 1:8600 in natural K, is slightly radioactive.
Is it ever isolated, like isolating deuterium(-oxide) from water ? Obviously not in an amateur lab, but a professional nuclear physics lab like in
Dubna.
Our body contains 20mg of K-40, equivalent to a pearl with a diameter of 3.5mm.
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unionised
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You can buy it.
https://www.isotopes.gov/catalog/product.php?element=Potassi...
I imagine you would need deep pockets.
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metalresearcher
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The K-40 sold by isotopes.gov is only 3-4% pure, so not well isolated. So I think that it is technically not possible or only with very hight tech
equipment in nanogram quantities.
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unionised
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I don't know how they get it to 4%, but if they took the stuff that's 4% and ran it through the same process again repeatedly I'm sure they could end
up with a high purity material.
Also, if you are prepared to accept microscopic quantities then anyone running an ICP/MS analysis of potassium will separate out the 40 mass unit
isotope.
But they won't keep it separate.
If you had enough money you could certainly get pure (ish) 40K.
Why do you ask?
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SWIM
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Worst case scenario it still ought to be easier than separating Uranium isotopes. (less relative mass difference than potassium isotopes)
We sure do lot of that, and we get those to well over 90% purity.
I bet the 4% is 4% because that's high enough for whatever purpose it's generally used for. Isotopic tagging maybe? making radioactive sports drinks?
who knows?
Well actually probably quite a few people here know, but I'm not one of them.
[Edited on 10-9-2017 by SWIM]
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metalresearcher
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Quote: Originally posted by unionised  | I don't know how they get it to 4%, but if they took the stuff that's 4% and ran it through the same process again repeatedly I'm sure they could end
up with a high purity material.
Also, if you are prepared to accept microscopic quantities then anyone running an ICP/MS analysis of potassium will separate out the 40 mass unit
isotope.
But they won't keep it separate.
If you had enough money you could certainly get pure (ish) 40K.
Why do you ask? |
Just for curiosity, I am not interested buying anything.
But in natural K, the K-40 is between K-39 (94%) and K-41 (6%), so the tiny amount of K-40 (1/8600) must be hard to isolate.
Or first isolate pure K-39 and then separate the remaining K-40 and 41 which is then in a ratio (100/6) * 1/8600 which is about 1:500.
Again, not suitable for an amateur lab.
[Edited on 2017-9-10 by metalresearcher]
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Felab
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A way to purify K40 would be taking advantage of the diferent rates of difussion of the diferent isotopes (K40 would difuse a bit slower than K39 due
to its greater mass).
Of course it would be slow and very tedious but certainly doable ( Cody's Lab attempted to do so but failed miserably)
Another methode that works (although being very energy intensive) is to submit a stream of charged atoms of a mix of K isotopes to a magnetic field in
a vacuum. The K40 atoms have a greater inercia than the K39 and therefore deflect less. This would only produce a few miligrams though but of a very
high purity.
[Edited on 12-3-2019 by Felab]
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Ubya
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| Quote: Originally posted by SWIM | Worst case scenario it still ought to be easier than separating Uranium isotopes. (less relative mass difference than potassium isotopes)
We sure do lot of that, and we get those to well over 90% purity.
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well K-40 is only 0.012% of the total potassium, while U-235 is 0.75%, 62 times more abundant.
it's not as easy as
| Quote: |
took the stuff that's 4% and ran it through the same process again repeatedly
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, to enrich uranium we already need thousands of centrifuges in series, and not all countries are able of
such thing, so imagine doing the same for K-40, an isotope not even as important as uranium.
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Vomaturge
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Potassium 41 has been isolated, in gram quantities, but it's not radioactive, it's far more abundant, and the process is still expensive.
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phlogiston
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To go from 0.014 to 4% take a lot more work than to go from 4% to 90+%, because you only have process much smaller amounts.
So putting it through the same process becomes progressively easier.
For Uranium, that is why a stockpile of lowish enriched uranium, say 20%, is a concern. It can be enriched to HEU very quickly.
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