Sciencemadness Discussion Board

deuterium oxide for rare earths

David Marx - 29-8-2004 at 17:56

I have several 1 gram samples of 100% D, deuterium oxide that I am willing to swap for lanthanide or actinide samples.

The samples are from a recognized isotope manufacturer and I would be happy to include a copy of the analysis for any takers.

Great for the curiosity factor if not the research application.

Addendum: for anyone desiring to own some deuterium oxide but not having anything nice to trade, I have listed a couple of ampoules on eBay.

[Edited on 30-8-2004 by David Marx]

Hang-Man - 29-8-2004 at 18:25

Your location would be helpfull, as I'm sure 'deuterium oxide' is a no-no with customs.

chemoleo - 30-8-2004 at 09:30

Well, it would be EXTREMELY HARD for a customs officer to determine that it is D2O rather than H2O.
1 ml is not a lot though. In my lab we got liters of the stuff - expensive, sure!
What could you do with D2O, apart from this being a collectors item? I.e. for the amateur chemist/physicist?

rift valley - 30-8-2004 at 10:04

They sell it at united nuclear pretty expensive though

Esplosivo - 30-8-2004 at 11:07

Is it true that D2O is produced by electrolysing normal water until reducing the volume substatially? Does anyone have any reference to such a procedure?

Well, lol, I don't suppose D2O has a wide use for the amatuer chemist. It can sure be used to synthesize organic compounds possesing deutrium instead of hydrogen, so to record the transfer of hydrogen atoms during a reaction, but that is surely no home-made experiment :P If one is really on to it, he could also try replicating the allegedly fusion of deutrium atoms by electrolysing D2O with palladium electrodes if I remeber correctly. But that would also require heaps of apparatus simply to calculate the minimal energy changes. So well, I suppose it can only be used as an 'ornament' :P

mick - 30-8-2004 at 11:25

Have had people put molecular sieve in D2O to keep it dry because it is hydroscopic
Mick
I mean hygroscopic

[Edited on 30-8-2004 by mick]

The_Davster - 30-8-2004 at 13:25

Quote:
Originally posted by chemoleo
What could you do with D2O, apart from this being a collectors item? I.e. for the amateur chemist/physicist?


Try to recreate the experiment that was suposedly cold fusion...
:D

David Marx - 30-8-2004 at 17:16

I ship from the USA for those of you concerned with your local customs agent.

You are all quite correct in that deuterium oxide is little more than a curiosity to the home chemist. Of course, so most likely is any lanthanide/actinide materials you might possess (barring those used in fireworks or as organic catalysts). So if you are tired with one curiosity, why not trade it for another new curiosity?

neutrino - 31-8-2004 at 06:49

Quote:
From Encarta
Several methods have been used to separate the isotope from natural hydrogen. The two processes that have been most successful have been fractional distillation of water and a catalytic exchange process between hydrogen and water. In the latter system, when water and hydrogen are brought together in the presence of a suitable catalyst, about three times as much deuterium appears in the water as in hydrogen. Deuterium has also been concentrated by electrolysis, centrifuging, and fractional distillation of liquid hydrogen.


I may be wrong, but the second method sounds like electrolysis. This is also mentioned here:

Quote:
From Encarta
Processors obtain deuterium oxide by making use of the fact that deuterium oxide boils at a slightly higher temperature and is harder to separate by electrolysis than protium water. Scientists can boil off or use electrolysis to drive off the protium water in a sample of regular water. In either method, the liquid left behind gets heavier and heavier as the concentration of deuterium oxide rises.


I think the basic procedure for the electrolysis is to take a very large amount of pure water (thousands of liters, I think) and electrolyze it until you have a small amount left. This is very high purity D<sub>2</sub>O.

JohnWW - 1-9-2004 at 15:08

D2O is produced mostly by fractional distillation, especially in Norway, which has plenty of cheap electricity - about the world's cheapest, I think. During WW2 the Germans had a large electric-powered D2O production plant in occupied Norway, as part of their efforts to make atomic bombs and harness nuclear power - but it was destroyed by Allied saboteurs and Norwegian Resistance agents.

I saw in a Sigma-Aldrich catalog of a few years ago that they (at least then) sold D2O and many deuterated organic compounds, presumably for studies of mechanisms of organic and biochemical reactions, with the aid of mass spectrometry and IR spectroscopy due to the effects of D on such spectra. They were very high-priced.

I also read somewhere that laboratory animal studies have shown that replacing much of the water in body fluids with D2O results in substantial slowing down of metabolism, with infertility being the first symptom. More than 25% D2O resulted in death.

John W.

Hermes_Trismegistus - 1-9-2004 at 15:15

Quote:

I also read somewhere that laboratory animal studies have shown that replacing much of the water in body fluids with D2O results in substantial slowing down of metabolism, with infertility being the first symptom. More than 25% D2O resulted in death.John W.


Imagine being a coroner trying to determine that cause of death.

on a quasi-related note, I'd like to take this opportunity to brag up Canuck ingenuity.

:D http://en.wikipedia.org/wiki/Candu

chemoleo - 1-9-2004 at 15:34

For the toxicity of deuterium oxide see
http://www.sciencemadness.org/talk/viewthread.php?tid=1003

Admittedly that's not on topic, so let's get back onto it!

Polverone - 1-9-2004 at 15:38

There seems to be a glaring contradiction in that wikipedia article:

Quote:
The moderator is in a large tank called a calandria, penetrated by several hundred horizontal pressure tubes which form channels for the fuel, cooled by a flow of heavy water under high pressure in the primary cooling circuit, reaching 290°C. As in the pressurized water reactor, the primary coolant generates steam in a secondary circuit to drive the turbines.
...
Since the core of the reactor is maintained at about room temperature and pressure, the equipment to monitor and act on the core is quite a bit less complex.


I suppose it runs at room temperature, if the room is on fire or we're just rounding to the nearest 1000 degrees. I think that 290°C water may be under more than an atmosphere or two of pressure, though.

This is actually the first obvious Wikipedia error I've come across in my browsing of their articles. That's fairly impressive, considering how open the system is.

[Edited on 9-2-2004 by Polverone]

Hermes_Trismegistus - 1-9-2004 at 15:52

Quote:

Admittedly that's not on topic, so let's get back onto it!


I dunno' chemoleo........... a dozen replies, and we have explored and discussed the availibility of a chemical, the isolation of that chemical, the toxicity of that chemical, and the technology that that chemical is primarily associated with.

That's fair to middling good for this forum.

I seem to remember one other thread that went from flaming felines...... to the unconcious equine sexual fantasies of the feminine sex, in about the same # of posts....eh!:P

chemoleo - 1-9-2004 at 16:21

no, all that was meant to be discussed was the swappability of D2O vs lanthanides.
Then the discussion of uses came up (to justify swappability). But toxicity is not really related there, is it?
Anyway... it is not that important.
Buy the D2O if u want to - I myself was fascinated by it one day. These days, since I have seen liters of D2O, I don't see why I got so excited about it.
I guess it's the usual thing - if you don't have it, you think it's the most exciting thing since sliced bread. But once u have it, a lot of chems lose their attraction.
Sad but it's true.... :(

David Marx - 1-9-2004 at 16:26

Quite true chemoleo, alot of chemicals do lose their appeal once the mystery goes out of them. I felt the same way when I first saw the little brown ampoules of deuterated solvents. Now, years later that appeal has mostly faded and I am more interested in continuing my experiments with f-group interactions.

I hope that someone is similarly disillusioned with their europium or gadolinium oxide or chloride samples and yearn for the chance to check out some D2O.

Marvin - 2-9-2004 at 09:55

"Have had people put molecular sieve in D2O to keep it dry because it is hydroscopic " (mick)

Yes, you'll get a lot of idiots in the labs if you dont keep the doors locked after hours.

Esplosivo,
If you electrolyse water using sodium hydroxide and nickel electrodes you get an enrichment factor of between 6 and 12. That is to say the hydrogen coming off will have 6 or 12 times less deuterium in it than would be isotopically normal. If you do this to a bath full of water, the last few grams will be decently pure D2O. Expensive.

Its about 4 to 7 litres for every ml of D2O, though you'll need about 30 litres for every ml to get D2O of a high degree of purity in a single batch process. Of course you cant top up the cell during the process because this would continually dilute it, it needs to be a single cell with good mixing between the water contained.

John,

"D2O is produced mostly by fractional distillation, especially in Norway, which has plenty of cheap electricity "

This is almost but not entirley wrong. Electrolysis was the only practical method of use during the war and the norway site was ideal because of the hydroelectric power station. Staged electrolysis was used, the hydrogen from some of the later stages is still in excess of natural so these were burned and fed back to earlier stages.

Nowerdays virtually all D2O is made by the Girdler sulphide process. Alternate hot and cold tubes increase deuterium enrichment in either H2S or water (depending on the temperature) in counter current towers. Usually 3 stages are used and the output is enriched to the tune of around 10% D2O. The prefered method of furthur concentrating 10% D2O to high purity D2O is by vacuum distillation.

1g of D2O is worth somewhere between 10c and 1USD depending on purity. It is used a lot in NMR experiments and analysis.

[Edited on 2-9-2004 by Marvin]

JohnWW - 2-9-2004 at 17:06

The use of partitioning between H2O and H2S to concentrate D in the water to the extent of 10% D2O is hazardous, due to H2S being very poisonous on inhalation, in the same manner as but even more so than CO or HCN or (CN)2 or HN3. So do not try it at home. Because the concentration beyond 10% D2O has to be by fractional distillation anyway as you say, its economics are somewhat questionable compared to doing it all by fractional distillation (or electrolysis), non-hazardous.

The lesser degree of electrolysis of D2O in water subjected to electrolysis with a suitable electrolyte would presumably be due to the lesser ionic mobility (and activity coefficient) of D+ compared to H+, resulting from its double mass.

Re NMR spectra of deuterated compounds: The deuteron has a much smaller magnetic moment than a proton, and signals from deuteron absorption do not occur in proton NMR spectra, as its approximately double mass accordingly affects its magnetic moment (which depends upon both single-proton spin of ½ and mass). This also opens up the possibility of deuteron NMR spectra. Spin couplings between deuterons and protons are small but the presence of D on an adjacent atom can cause splitting of the proton signal. In addition, the extra mass of D compared to H greatly slows down tautomeric interconversions, especially at low temperatures, e.g. of the two possible chair forms of undecadeuterocyclohexane, C6D11H, to the extent that the two different H shifts can be easily detected by NMR.

Deuteration would be of at least equal importance (to NMR) for its effect on IR and mass spectra, due to its direct effect on the masses of substituted hydrogens.

John W.

Questionable Economics?

Hermes_Trismegistus - 2-9-2004 at 18:43

Power is quite cheap in Canada (world's largest producer of D :D) but going from 1/7000 ----> 1/10 conc. with as cheap of a chemical as H2S prior to mechanical seperation seems economically sound to me (humble resident wannabe).

Of course, I have the benefit of agreeing with current industrial practice, and it's relatively easy to flow downstream.:)

Marvin - 3-9-2004 at 08:10

Girdler sulphide isnt feasable at home, since a home version of the process for small amounts would need towers the same length as the real thing in order to get the same concentration out.

H2S is toxic, but in the industrial setting it forms a closed circuit, so its reasonably enviromentally sound.

"Because the concentration beyond 10% D2O has to be by fractional distillation anyway as you say, its economics are somewhat questionable compared to doing it all by fractional distillation (or electrolysis"

Nonono. Economics of the sulphide process is not in question, its without doubt the cheapest way of doing it by a long way. It pans out thus,

For the first stages you want to process massive amounts of water at very little cost per unit volume and it doesnt matter if only a low percentage of deuterium make it into the concentrated section. The raw material is free. In the GS process only about 1/5th of the deuterium in the feed water makes it into the 10% output at the end. It simply isnt worth improving the process to get more out when the waste is just rejoining the river anyway.

In addition the temperatures used are low, about 100C seperation or less, so this can use waste heat from a power plant. Heat exchangers are used at every stage to furthur conserve power.

When you get the enriched output its more important virtually all of the D in the 10% make it to the high concentration form, and cost per unit volume is less important as it makes much less impact on the overall price of the product.

Electrolysis is the most selective and the most expensive per unit volume of water processed, so its very badly suited to early stages of enrichment. The Norway plant was an absolute gift to the germans because it was producing hydrogen electrolytically for industrial purposes anyway. It only needed to be adapted and D2O came off with very little extra power as a byproduct.

The bottom line is, there is no way of making small amounts of D2O at home more cheaply than you can buy it. Even if you tried there is essentially no way of determining how much the natural water has been enriched until it gets high enough to measure changes in density.

D2O is used routinely in NMR, both for calibrating the instruments and simplifying the spectrum of organic compounds. For example an organic compound shaken with D2O will exchange D for the H on all acidic groups (acids, alcohols) and so these will vanish from the proton spectrum.

Deuteron NMR does not have much use as being quadropolar its line width is too large to resolve detail. The magnetic moment and Lamor frequency do not depend on the mass of the nucleus, they are quantum effects.

JohnWW - 4-9-2004 at 04:42

Quote:
(cut) D2O is used routinely in NMR, both for calibrating the instruments and simplifying the spectrum of organic compounds. For example an organic compound shaken with D2O will exchange D for the H on all acidic groups (acids, alcohols) and so these will vanish from the proton spectrum. (cut)


But the shift of carboxylic acid Hs are by far the largest in proton NMR spectra of organic compounds because of having the greatest level of deshielding, and so have very distinctive NMR spectral signals, anyway, usually easily capable of being distinguished from alcoholic and phenolic Hs. Using D2O to replace these (being the most labile Hs in organic chemistry) with D, which does not show up in proton NMR, would thus be of limited use. The only possible exceptions would be in compounds like trinitrophenol (picric acid), where strongly deshielding nitro groups in the alpha-positions result in the -OHs being acidic, similar to carboxylic acids.

John W.

mick - 4-9-2004 at 19:53

If you were full of D2O it would realy confuse them if you had a MRI scan
Mick

no kidding.

Hermes_Trismegistus - 4-9-2004 at 20:00

MRI'ing a corpse would probably confuse a medtech.

Marvin - 4-9-2004 at 22:36

John,

Once again you are speculating with no information and no experience only because you want to boost your post count. Ive allready said, it works fine with alcohols and that it is used routinely. It also works fine with many other functional groups that hydrogen exchange.

Hermes, they prefer to be called metabolically challenged and I imagine long hospital waiting lists mean the medtechs see more than a fair share.

Proteios - 4-9-2004 at 23:20

Quote:
Originally posted by Marvin
John,

Once again you are speculating with no information and no experience only because you want to boost your post count. Ive allready said, it works fine with alcohols and that it is used routinely. It also works fine with many other functional groups that hydrogen exchange.

Hermes, they prefer to be called metabolically challenged and I imagine long hospital waiting lists mean the medtechs see more than a fair share.


right on Marvin!

in neutron scattering D is preferential over H due to its higher coherent scattering cross section, lower incoherent cross section and reduced inelastic scattering problems......put simply... in neutron scattering D2O is used like water!.....(golly... if you didnt know that.... file it away under life altering information!)... but it brings a smile to the face that there are people around who treasure 1ml of D2O and think the feds r gonna bang em up for it!.... chuckle!

JohnWW - 5-9-2004 at 01:47

That last post - re neutron scattering properties of D2O - has NOTHING to do with the effect of D on NMR spectra! There is no way that it can be a legitimate criticism of my last post.

I stick by what I said in my last post. The Hs in alcohols are much less acidic, and hence much less labile (liable to ionization and exchange with D from D2O), than in carboxylic acids (which have O= on the same carbon), and indeed are less acidic than water. UNLESS, as I said before, there are strongly electron-drawing groups like -NO2 on either the same carbon or a neighbouring carbon (which also results in deshielding of the alcoholic (or phenolic) H and hence shift in NMR spectra).

Besides, only a relatively few short-chain alcohols (and phenols) are soluble in water (or D2O). The longer-chain ones are insoluble waxes or oils, which rules out even trying to exchange their alcoholic Hs with D2O. Carboxylic acids with the same numbers of carbons are much more water-soluble, due to their greater polarity.

John W.

mick - 5-9-2004 at 05:15

Carrying out reactions in deuterated solvents and using stuff like deuterated acetic acid, sodium hydroxide, pyridine etc is useful because it can make it easier to follow some reactions by NMR.
Mick

Proteios - 5-9-2004 at 11:12

Quote:
Originally posted by JohnWW
.. has NOTHING to do with the effect of D on NMR spectra!
John W.


...chuckle... i think u might have missed the point.....D2O is very common. However the statement above is not true... both neutrons scattering properties and NMR spectra depend upon nuclear spin. Youre right about the acids though.

Marvin - 9-9-2004 at 06:07

Disentangling the threads somewhat,

John wrote in the deuterated acetone thread,

"As for alcohols not exchanging Hs with D2SO4, I only went so far as to say that the rates of such an exchange would be much less than that of carboxylic acids due to the much lesser degree of ionization; and that it would practically not happen for other than the shortest-chain alcohols, because higher alcohols (which are waxes and oils) are practically insoluble in water."

We wernt discussing alcohols with D2SO4, just plain D2O. Even moderatly concentrated D2SO4 in D2O would be expected to cause oxygen exchange, which is another level entirly.


In this current thread,
"....I stick by what I said in my last post. The Hs in alcohols are much less acidic, and hence much less labile (liable to ionization and exchange with D from D2O), than in carboxylic acids (which have O= on the same carbon), and indeed are less acidic than water. UNLESS, as I said before, there are strongly electron-drawing groups..."

Going from a random webpage from google the timescale for most alcohols are 10^-5 seconds for an exchange. This is not slow.

http://www.chemistry.ccsu.edu/glagovich/teaching/472/nmr/cou...

A textbook grabbed from the shelf behind me, "Spectroscopic methods in organic chemistry" a pretty standard undergrad textbook calls it the "D2O shake" and its number 3 on the tips for determining an unknown structure right behind identifying solvent peaks and trying to find an integral for a single proton. How much more basic a method can you get!

The 'method' if you can call something so simple a method says 'if the sample in CDCl3 or CCl4 solution, is shaken with a drop of D2O the OH NH and SH hydrogens exchange rapidly with the deuterons, the HDO floats to the surface out of the region examined by the spectrometer and the signal of the OH NH or SH simply dissapears from the spectrum (or more usually is replaced by a weak signal close to d4.8 coming from suspended droplets of HDO).

and later on,
"Besides, only a relatively few short-chain alcohols (and phenols) are soluble in water (or D2O). The longer-chain ones are insoluble waxes or oils, which rules out even trying to exchange their alcoholic Hs with D2O. "

Irrelavent, as is commonly known, and mick has already pointed out in the other thread anyway, the solvent for NMR is usually organic and more frequently chloroform or carbon tet. Pure compounds are not used.


and from much earlier,

"But the shift of carboxylic acid Hs are by far the largest in proton NMR spectra of organic compounds because of having the greatest level of deshielding, and so have very distinctive NMR spectral signals, anyway, usually easily capable of being distinguished from alcoholic and phenolic Hs. Using D2O to replace these (being the most labile Hs in organic chemistry) with D, which does not show up in proton NMR, would thus be of limited use. "

Removing these lines is not just about having less lines on the spectrum. Proton exchange also blurs static hydrogen lines making multiplets more difficult to interpret, and as the molecules get more complex the job of interpreting goes up massively.

I trust this clarifies the matter.
It does work, it is used often and it is not of very limited help.

[Edited on 9-9-2004 by Marvin]

mick - 10-9-2004 at 04:25

If you run a COSEY and NOESY experiment on a fairly complex compound containing sugar and/or protein residues before and after a D2O shake there is a good chance that you can work out the 3D structure in solution. It is a fairly powerful tool. The instuments today have superconducting magnets and work on the FT principle. There is an excellent free FT-NMR conversion program on the net. The old ones had a large magnet and worked with radio wave frequences, they always looked fairly straight forward to me. Does anyone know the most powerful magnet that can be built at home, I will have a look. Home built NMR instrument? Some thing to think about.
Thanks
mick

Typo

[Edited on 10-9-2004 by mick]

JohnWW - 10-9-2004 at 09:08

Because of other electron-drawing groups in the molecules, often vicinal, the alcoholic Hs in saccharides and any in peptides should be more labile (more capable of exchange with D2O) than those in ordinary alcohols, and the molecules themselves would be (for chains of the same lengths) more water-soluble for the purpose. At the same time, their -OH NMR shifts would be intermediate between those of ordinary alcohols and of carboxylic acids, and similar to those of -OHs with e.g. alpha-nitro groups, posing difficulty in identifying them. This would be reflected in their acid dissociation constants. So in this case, exchange of H for D using an excess of D2O, to modify the NMR spectrum so as to determine the -OH environment, is certainly useful.

As regards making your own NMR spectrometer - you could look up patents (most of which should have expired by now) for them with the US Patent Office, and other countries' patent offices. Many patents are on-line on their websites. But it would be fairly expensive. Varian Associates seems to be the longest-established and best-known maker of NMR spectrometers.

John W.

mick - 10-9-2004 at 10:07

A home made NMR should be possible. You spin the stuff in a big magnet, more of the protons spin in the same direction due to the magnetic field. Hit them with a broad band radio frequence and some off them will spin the other way absorbing the radio frequency. Measure the output and you could get an NMR spectra. I know there is a problem with relaxation time and other stuff but if you used modern electrics it could be better than the original, and no superconducting stuff. I think you could get a good NMR from 40MHz magnet, I think they go upto over 900MHz now.
mick
The edit was because I forgot to sign it

[Edited on 10-9-2004 by mick]

Proteios - 10-9-2004 at 10:42

Quote:
Originally posted by JohnWW
Because of other electron-drawing groups in the molecules, often vicinal, the alcoholic Hs in saccharides and any in peptides should be more labile (more capable of exchange with D2O) than those in ordinary alcohols, and the molecules themselves would be (for chains of the same lengths) more water-soluble for the purpose. At the same time, their -OH NMR shifts would be intermediate between those of ordinary alcohols and of carboxylic acids, and similar to those of -OHs
John W.


a nice piece of specious reasoning there...... peptide hydrogens are really quite non-acidic due to the resonance/hydbridisation.....or whatever chemical handwaving you want.... but the bottom line is.....peptide hydrogens are relatively very stable/non-acidic (ergo proteins dont fall apart that easily). Google before flight of fantasy on what you think the universe should look like.

Your hand waving on chemical shifts leaves something to be desired too!

Marvin - 11-9-2004 at 11:11

Home NMR is something I've considered. A feasable electromagnet would be limited by iron saturation at (from memory) about 2.2 Tesla, this would be enough for a 100MHz (proton, as will all the numbers I quote be) NMR machine.

Making a magnet at home would be a nightmare though, you need field homoginity in the 1 part in 100 million, or better, 1 billion range for decent NMR and theres only so far winding your own shim coils will go. The magnet itself would take a lot of power unless the sample area is tiny. Moving down to 60MHz would help a lot. Perminant magnet systems are then feasable, or electromagnet systems become a lot easier. Very very accurate machining of the iron core would be needed to even attempt this, an off the shell magnet not specifically designed for NMR would be useless.

If you can find a secondhand NMR magnet (not superconducting obviosly) this cuts out a lot of problems.

Youd need to be a good radio engineer to build a 100MHz or 60MHz setup electronics. Youd have to superheterodyne the thing into low noise filters and the whole project is more like a lifes work if you add a stable magnet to the construction list.

Seems like a reasonable point in a relevent thread to talk about my own plans for a NMR spectrometer. Audio frequency!

Now why the hell would anyone want an audio frequency NMR spectrometer you ask, and you ask it because you'd lose all the information regarding molecules. The answer is that its still useful because you can still determine isotopes and their concentrations. For those people with little imagination, call it a 20th century tricorder. You put the sample of a few hundred ml solution inbetween a Helmholtz magnet, you have a pick up and drop (in nuclear terms) magnetic field switching on and off, the audio coil wrapped round the sample is connected to an amplifier, to a filter, to another amplifier (gain of a million or more needed) and then into a PC soundcard and signal avaraging coaxes a spectrum out of the noise over time, (say an hour or so).

From that you get a list of concentrations of all 'visible' isotopes (with a non zero magnetic moment, ie all with odd numbers of neutrons or an odd number of protons).

Cheep, cheerful and lets you try isotopic enrichment at home, want to know how much deuterium is in that solution after electrolysis? Shout at it and for some basic electronics (in addition to a PC), less complicated than a ham radio you can hear the reply.

There are only a few elements that wouldnt show up at all if you want to do elemental analysis and you are happy to assume natural abundances. Cerium is one. There are a fair few elements that might be impractical to see in reasonable time though, being a very low field instrument sensitivity suffers horribly.

And I know what some people would be thinking, why cant we use a nice stable Helmholtz field to do high field NMR. The answer is with only a few kilograms of copper (reasonable assumption I think) in coil windings and a reasonable sized coil (circa 10cm I think my math was for), youd be talking a kilowatt+ to get more than a few thousand gauss (1000 gauss = 0.1Tesla) and with power usage going up with I^2R but field strength only going up with I, this is close to limiting for this idea, 5 to 10MHz proton NMR not being useful for molecules. I do have some tricks up my sleeve for increasing the resolution of a 60 or 100MHz instrument, but it couldnt be used commercially as it would take far to much time. I did think about patenting the idea for an NMR device that did mineral analysis or isotopic analysis with audio frequency, but again only amateurs would be willing to wait hours or overnight for a single sample result.

mick - 12-9-2004 at 06:25

Thank
Point taken. The idea came from looking at Mr Fusions stuff with the nice array of magnets. A couple of years ago an old 60 MHz NMR got skipped. The worst one I think I have missed is all the old PYE 104 GLC's. They seemed to be so straight forward and repairable. You could plug bits into them to up grade them and unplug the bits and the thing would still work.
I like the idea of isotope detection, you are looking for the the isotope and not environment. Analysis is 99% knowing what you are looking for.
mick

A quick edit on analysis
A chap thought his radio receiver on the roof had been sabotaged and it was personal. It looked like silicone sealant. A quick test in a bunsen flame proved it was bacon rind. I think it was security or some one eating a bacon sandwich.
mick

[Edited on 12-9-2004 by mick]

mick - 12-9-2004 at 10:55

I was thinking that if you got some of these NeFeB magnets and clamped them in the right position then something must happen to the nuclei , it is just measuring it that is the problem.
mick
Typo
Spelling is not very good, chemistry OK

[Edited on 12-9-2004 by mick]