Natural abundance of heavy water
Gerry Niccolai
in the expected (by me, anyway) natural abundance of one
molecule of D2O per about 36 million water molecules?
Please, respond only if you cite EXPERIMENTAL evidence (IR?
Mass spec?).
Thank you in advance,
gerry
PS - The final objective being an estimation of the amount of
D2O present on earth from natural sources as opposed to
synthetic sources, so an estimation of the amount of water on
earth would be helful as well. Where does commercial D2O come from,
anyway?
Don Wiles
> Thank you in advance,
> gerry
Quoting from Cotton and Wilkinson (Advanced Inorganic Chemistry)
"Naturally occurring hydrogen contains 0.01556% deuterium....." That
agrees well with the old rule of 1 in 6000. Statistically, about 1
water molecule in 36,000,000 would have two deuterium atoms.
Goran Olsson, Plasma Physics, KTH
>Gerry Niccolai (ge...@cismibm.univ-lyon1.fr) wrote:
>> Can anyone confirm that heavy water (D2O) occurs in sea water
>> in the expected (by me, anyway) natural abundance of one
>> molecule of D2O per about 36 million water molecules?
>> PS - The final objective being an estimation of the amount of
>> D2O present on earth from natural sources as opposed to
>> synthetic sources, so an estimation of the amount of water on
>> earth would be helful as well. Where does commercial D2O come from,
>> anyway?
>Quoting from Cotton and Wilkinson (Advanced Inorganic Chemistry)
>"Naturally occurring hydrogen contains 0.01556% deuterium....." That
>agrees well with the old rule of 1 in 6000. Statistically, about 1
>water molecule in 36,000,000 would have two deuterium atoms.
Better also mention that heavy water is made (was originally made?)
through repeated electrolysis of natural water where deuterium gets
enriched in the water remaining (or is it the opposite?). Someone here
might be able to point to more efficient processes, involving other
D/H molecules.
And also that you don't have to process 36,000,000 molecules for every
D2O. Disregarding losses, 6000 will do, since the exchange 2 H2O <->
H3O + OH is going on all the time, and D gets redistributed.
This process is probably what the original poster would call
a natural source.
Synthetic sources? A little deuterium is produced in water cooled nukes,
but this must be completely insignificant.
Goran
Gerry Niccolai
: In article dwi...@ccs.carleton.ca (Don Wiles) writes:
: >Quoting from Cotton and Wilkinson (Advanced Inorganic Chemistry)
: >"Naturally occurring hydrogen contains 0.01556% deuterium....." That
: >agrees well with the old rule of 1 in 6000. Statistically, about 1
: >water molecule in 36,000,000 would have two deuterium atoms.
But they don't quote experience, only deduce heavy water in
water as the logical extension of deuterium in hydrogen.
: Better also mention that heavy water is made (was originally made?)
: through repeated electrolysis of natural water where deuterium gets
: enriched in the water remaining (or is it the opposite?). Someone here
: might be able to point to more efficient processes, involving other
: D/H molecules.
That rings a bell. I learned that electrolysis being a method of
enriching water in deuterium. At %D > 50, we are *sure* to
have some D2O, but my objective is to find proof that D2O is
present in naturally occuring water. (Again, I have *no*
reason to believe it isn't, I am trying to convice someone
that it is, but being a pure skeptic, he will not accept "it
should be" as a valid arguement.) Thus, again, I would like
in situ, experimental evidence.
<snip - I didn't quite understand what you meant, anyway>
: Synthetic sources?
I should have said industrial source. It is produced on the
millions of tons per year scale somewhere, somehow.
gerry
Felices ruri hodie,
Semper ruri felices.
Andrew M. Gough
[snip]
>
> I should have said industrial source. It is produced on the
> millions of tons per year scale somewhere, somehow.
>
> gerry
Several years ago, about a month after the "Cold Fusion" announcement
and controversy began, I picked up an issue of Radio Electronics
magazine (a magazine that always has a lot of good home electronics
projects) because on the cover it had "Cold Fusion? Try It At Home!"
There was quite a long article on creating a Pons/Fleishman cold
fusion setup. An important part of the project is obtaining the
materials--the palladium, the platinum ($$$), and the heavy water.
The auther discussed the supply of heavy water. He said there were
two kinds of sources 1) extremely pure heavy water for laboratory
use, and 2) bulk heavy water in ton quantities, produced as a
byproduct of sulfuric acid manufacturing.
So . . . I don't know why sulfuric acid manufacturing would produce
heavy water as a byproduct. I bet someone on the net knows . . . right?
Regards,
Andy
Disclaimer:
All views expressed are my own opinions, and not necessarily
those of Intel Corporation.
--
_______________________________________________________________________________
Andy Gough | Internet: andrew_...@ccm.ch.intel.com
Intel Corporation CH5-131 | ICBM : 111^55'42" W; 33^18'23" N
5000 W. Chandler Blvd. | "Knowledge is power."
Chandler, AZ 85226 | -- Francis Bacon
-------------------------------------------------------------------------------
Phillip Bigelow
>: Better also mention that heavy water is made (was originally made?)
>: through repeated electrolysis of natural water where deuterium gets
>: enriched in the water remaining (or is it the opposite?). Someone here
>: might be able to point to more efficient processes, involving other
>: D/H molecules.
>That rings a bell. I learned that electrolysis being a method of
>enriching water in deuterium. At %D > 50, we are *sure* to
>have some D2O, but my objective is to find proof that D2O is
>present in naturally occuring water. (Again, I have *no*
>reason to believe it isn't, I am trying to convice someone
>that it is, but being a pure skeptic, he will not accept "it
>should be" as a valid arguement.) Thus, again, I would like
>in situ, experimental evidence.
I know nothing about your original question, but concentrating D20
rings a bell. In an old _Radio Electronics_ article (1980's I think), it
discussed one way to concentrate the stuff:
Fill a glass with water, then using electrolysis, zap the stuff down to a
point where the container has one half of it's original volume of water.
Then fill the glass up to the top with extra water. Zap it down to one half
it's original volume of water. Repeat the process a couple thousand times.
There's your D20. Not pure, but a lot more concentrated than D20 in regular
water.
--
<pb>
/ "In evolution, sometimes you're a fly. \
/ Other times, you're the windshield." \
Louis Psihoyos
Ian D. Gay
>In article <3no1go$d...@cismsun.univ-lyon1.fr>, Gerry Niccolai writes:
>[snip]
>The auther discussed the supply of heavy water. He said there were
>two kinds of sources 1) extremely pure heavy water for laboratory
>use, and 2) bulk heavy water in ton quantities, produced as a
>byproduct of sulfuric acid manufacturing.
>So . . . I don't know why sulfuric acid manufacturing would produce
>heavy water as a byproduct. I bet someone on the net knows . . . right?
Sounds like somebody is mixed up. Bulk D2O is mainly produced by H/D
exchange between H2O and H2S. So there is S involved, but not H2SO4.
(Unless oxidation of residual H2S produces it as a trace impurity in
the D2O ?)
Jeff E. Janes
:
: I should have said industrial source. It is produced on the
: millions of tons per year scale somewhere, somehow.
millions of tons? really? That should have put it in the C&EN top 50
chemical products list, but it wasn't there. Of course, they only count
US production.
--
Jeff Janes jej...@mtu.edu at Michigan Technological University
We have physicists, geometricians, chemists, astronomers, poets,
musicians and painters in plenty; but we no longer have a citizen among
us. --Jean Jacques Rousseau
Roy Jensen
To answer your last question:
> PS - The final objective being an estimation of the amount of
> D2O present on earth from natural sources as opposed to
> synthetic sources, so an estimation of the amount of water on
> earth would be helful as well. Where does commercial D2O come from,
> anyway?
D2O comes from regular, everyday, water! The NATURAL abundance of
1H is 99.985% and of 2H (deuterium) is 0.015%. Thus you are going to get
the following combinations with appropriate probabilities:
HOH 0.97066
HOD 0.02912
DOD 0.00022
Thus, 4500 molecules of water has: 1 molecule of D2O
131 molecules of HOD
4368 molecules of H2O
D2O is isolated based on it's increased mass over H2O and HOD. I am not
sure of the exact mechanism, but someone will enlighted us.
Natural abundances of the isotopes from the
CRC Handbook of Chemistry and Physics.
__________________________________
> Can anyone confirm that heavy water (D2O) occurs in sea water
> in the expected (by me, anyway) natural abundance of one
> molecule of D2O per about 36 million water molecules?
Nope. How did you arrive by this value?
> Please, respond only if you cite EXPERIMENTAL evidence (IR?
> Mass spec?).
Natural abundances have been known for a LOOONNG time.
Hope this helps.
Roy Jensen
rje...@sol.uvic.ca
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
* Imagination is more important than knowledge. *
* Einstein. *
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Jeff E. Janes
: On 26 Apr 1995, Gerry Niccolai wrote:
:
: D2O comes from regular, everyday, water! The NATURAL abundance of
: the following combinations with appropriate probabilities:
:
: HOH 0.97066
: HOD 0.02912
: DOD 0.00022
:
: Thus, 4500 molecules of water has: 1 molecule of D2O
: 131 molecules of HOD
: 4368 molecules of H2O
Uh, no. That is not right. Your numbers would be close to right if
the abundance of 2H were 1.5%. at 0.015% you are extremely wrong.
:
:
:
: > Can anyone confirm that heavy water (D2O) occurs in sea water
: > in the expected (by me, anyway) natural abundance of one
: > molecule of D2O per about 36 million water molecules?
I get more like 44 million, which I would consider close enough.
:
: -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
: * Imagination is more important than knowledge. *
: * Einstein. *
: =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Clearly :)
:
Gerry Niccolai
: Gerry Niccolai (ge...@cismibm.univ-lyon1.fr) wrote:
: :
: : I should have said industrial source. It is produced on the
: : millions of tons per year scale somewhere, somehow.
: :
: millions of tons? really? That should have put it in the C&EN top 50
: chemical products list, but it wasn't there. Of course, they only count
: US production.
I made up the number. "Lots" would probably have been a more
accurate description.
Gerry Niccolai
I never thought this question would take so long to answer.
Several have misunderstood the question. Take it as given that
the isotopic abundance of deuterium with respect to 1H in
water is, indeed, 1/6000. If the distribution is statistical,
that means that the occurence of D2O is (1/6000)^2 or
(1/36000000). Fine so far.
But what if one supposes that all of the deuterium in water is
in HDO molecules? Electrolysis or whatever removes H2O
selectively. We are only sure to have D2O in the mixture at
%D > 50.
I was hoping that somebody would respond to this thread "Of
course D2O is present in water, you dummy. It has IR bands
at 2xxx, 2xxx, etc. I see it every day and it gives me
headaches because I am looking for something w/ bands at
2xxx..."
So far, no one has cited experimental observation of D2O in
"normal" water.
Tomas Eriksson
Mass spectroscopy should be a good method to detect ratios of H2O, HDO
and D2O (mass 18, 19 and 20) when there are decent amounts of each.
However, I don't expect your average MS equipment will allow you to
measure a peak of 1 at 20 and a peak of 36000000 at 18... But it will
deifinitely allow the detection of D2O far below 50% D. I could probably
get a drop of D2O from my NMR colleagues, but I don't have a mass
spectrometer, and I wouldn't like to ask any colleague's permission to
inject water into their high vacuum system... Someone must have done
this sometime, I'd say. Have the honourable original poster conducted a
completely exhaustive search of CA and CZ back to anno dazumal? :-) :-)
The question is quite interesting though. I don't expect the deviation
from statistical distribution to be large, but I think it's conceiveable
that there is a very, very small deviation. H2O, HDO and D2O will have
different vibrational contributions to their free energy, because they
will have different vibrational frequencies. HDO will also differ in its
vibration modes, since belongs to another point group, i.e. is less
symmetrical. Vibrational energies in the liquid state isn't exactly
uncomplicated though... But possibly, the reaction H2O + D2O --> 2 HDO
could have a very small vibrational dG contribution. So, the avergae
distribution needn't be "statistical" down to the last atom.
Tomas
-------------------------------------------------------------------------------
L. G. Tomas Eriksson tom...@physchem.kth.se
Ph.D. student, Department of Chemistry/Physical Chemistry,
Royal Institute of Technology, Stockholm, Sweden
John Vinson
>>my objective is to find proof that D2O is
present in naturally occuring water. (Again, I have *no*
reason to believe it isn't, I am trying to convice someone
that it is, but being a pure skeptic, he will not accept "it
should be" as a valid arguement.) Thus, again, I would like
in situ, experimental evidence. <<
Would he accept mass spectrometry as evidence? Most mass specs
I've seen have a little "noise" from environmental water around
mass 18: and I'm sure that if you blew that area up, you would
see peaks from 18 (H2[16]O) up to 22 (D2[18]O). But HDO would
be the biggest isotopic peak - I suppose you could call it "half
heavy" water.
Tryggvi Emilsson
If you want to measure H2O/HDO/D2O ratios you don't stick water into a mass
spectrometer*.All you would see is the ratio of the naturally ocurring oxygen
isotopes.(16/17/18==99.759/.0374/.2039). To get the H/D ratio,reduce the
water to hydrogen,then measure the ratio of masses 2,3 and4.
T.Emilsson
*Unless your MS can resolve 19.0168 from 19.01478, ie.: HDO(16) from H2O(17).
Bhart Indu
water. First D2O can be separted from regular water by repeated fractionation
Boiling point of D2O is slightly different from H2O say approx 0.1 deg.
This difference is used to separate D2O. Once separted, it can be analyzed
by NMR etc.
--
Bhart Indu
Georgia Institute of Technology, Atlanta Georgia, 30332
Internet: b...@prism.gatech.edu
Tomas Eriksson
>tom...@physchem.kth.se (Tomas Eriksson) writes:
>>Mass spectroscopy should be a good method to detect ratios of H2O, HDO
>>and D2O (mass 18, 19 and 20) when there are decent amounts of each.
>
>spectrometer*.All you would see is the ratio of the naturally ocurring oxygen
>isotopes.(16/17/18==99.759/.0374/.2039). To get the H/D ratio,reduce the
>water to hydrogen,then measure the ratio of masses 2,3 and4.
>T.Emilsson
>
>*Unless your MS can resolve 19.0168 from 19.01478, ie.: HDO(16) from H2O(17).
Too bad... But if we detect H2, HD and D2 instead of H2O, HDO and D2O we
haven't really solved the problem as posed, i.e. detected D2O *directly*.
We could still use MS, but subtract the background at mass number 20
from H_2^18O. This isn't very elegant, but say that we can detect 0.1%
D2O (signal-background = 0.5 * background). This is equivalent to
detecting D2O when the D contect is about 3%. So we would have proven
that we do have D2O also when D < 50% of (H+D).
The obviously "simple" solution would be to use purer ^16O to burn H2
and D2, and use the water thus purified. Experimentally, this seems like
overdoing things...
Well, perhaps we have to rely on spectroscopy after all..
Wheatley N
> Although there is probably no direct proof of observation of D2O in
>water.
>
Mass spectrometry?
Chris W Thomas
>Gerry Niccolai writes:
>
>>>my objective is to find proof that D2O is
>present in naturally occuring water. (Again, I have *no*
>reason to believe it isn't, I am trying to convice someone
>that it is, but being a pure skeptic, he will not accept "it
>should be" as a valid arguement.) Thus, again, I would like
>in situ, experimental evidence. <<
>
natural abundance of D2O is simply the product of these probabilities
(neglecting any oxygen isotopes)
the natural abundance of D2O would be 0.000156 * 0.000156 = 24.3 ppb
Of course, this is not true because we aren't considering the source of
natural water. Whatever chemical means produced this natural water, be
it biological, electrical, geological, etc.) will occur via differing
pathways; each of which will exhibit their own isotopic effect.
So, we can rationalize the natural existence of D2O, but we don't feel
like determining the isotope effects for ALL possible means of producing
water.
Instead, why don't we consider this problem: what would be the
properties of a crystal of 100% H2O? or D2O?
Regards,
Chris W Thomas
cth...@ucsd.edu
http://nssgi-1.ucsd.edu/~cthomas/tor.html/
Roy Jensen
********* I G O O F E D **********
I wrote a lot of stuff about the D2O and it's NATURAL abundance.
I posted that:
> : HOH 0.97066
> : HOD 0.02912
> : DOD 0.00022
> :
> : Thus, 4500 molecules of water has: 1 molecule of D2O
> : 131 molecules of HOD
> : 4368 molecules of H2O
Which is NOT CORRECT. I used percentages instead of probabilities.
0.015 % abundance == 0.00015 probability
The correct values are as follows:
The NATURAL abundance of 1H is 99.985% and of 2H (deuterium) is 0.015%.
Thus you are going to get the following combinations with appropriate
probabilities:
HOH 0.999700022
HOD 0.000299955
DOD 0.000000022
Thus, 44 million molecules of water has: 1 molecule of D2O
6599 molecules of HOD
43.987E6 molecules of H2O
Sorry for any inconvienience.
Roy Jensen
rje...@sol.uvic.ca
Jorgen Skyt
: On 26 Apr 1995, Gerry Niccolai wrote:
: Thus, 4500 molecules of water has: 1 molecule of D2O
: 131 molecules of HOD
: 4368 molecules of H2O
: D2O is isolated based on it's increased mass over H2O and HOD. I am not
: sure of the exact mechanism, but someone will enlighted us.
Well for some reason it's much more easy to split H20 in H2 and O2, than
to split D2O in D2 and O2. This is used to concentrate the amount of D2O
in normal water. And therefore the cheap energy and clean water in Norway
was very important during WWII. And therefore british commandos and
resistance-heros of norway blowed up a big heavy-water plant in norway.
When first concentrated (how much, I don't remember) further separation
can be made using the strange behavior of water a little above freezing
point. As far as I remember (haven't looked it up yet), H2O has its
lowest density at 4 deg. celsius, while D2O has its lowest density at 11
deg. celsius.
The concentration of D2O happens in many steps, but to my knowlegde it is
not possible to go further to extract T2O from the water. Much easyer to
make artificial.
Joergen Skyt
Denmark
John Morriss
JE>: > in the expected (by me, anyway) natural abundance of one
JE>: > molecule of D2O per about 36 million water molecules?
JE>I get more like 44 million, which I would consider close enough.
What everyone seems to be forgetting is that any particular D or
H atom will be swapping in and out of one water molecule after
another many times a second.
So, if a D2O molecule exists, it probably won't in a microsecond
or so... But another one will...
---
* OLX 2.1 TD * Life would be easier if I had the source code...
raeesch...@gmail.com
> Can anyone confirm that heavy water (D2O) occurs in sea water
>
> Mass spec?).
>
>
> gerry
>
> D2O present on earth from natural sources as opposed to
> synthetic sources, so an estimation of the amount of water on
> earth would be helful as well. Where does commercial D2O come from,
> anyway?
