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Apolo707
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Diethyl ether peroxide formation prevention
Hello! This is my first post on this forum, so please don't judge me if this isn't in the right section. Anyway, I wanted to ask if storing diethyl
ether over sodium hydroxide really prevents the formation of peroxides on a 2-year time-scale. Has anyone tried this method and, after 2 years or
more, tested for peroxides with negative results?
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Sulaiman
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Welcome,
The SM search engine is not the best, better to use Google
e.g. to look for diethyl ether peroxide
in the google search bar type
site:sciencemadness.org diethyl ether peroxide
CAUTION : Hobby Chemist, not Professional or even Amateur
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Apolo707
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Quote: Originally posted by Sulaiman  | Welcome,
The SM search engine is not the best, better to use Google
e.g. to look for diethyl ether peroxide
in the google search bar type
site:sciencemadness.org diethyl ether peroxide |
I did this, but all the documents I found said something among the lines of "It is recommended to store diethyl ether over sodium hydroxide or sodium
metal to prevent the build-up of peroxides" without specifying to what degree this is effective. I would like if someone testifies that they have had
success with this method on a 2 year time-scale, or finds a paper testing the efficacy of different methods of preventing peroxides (for example,
testing the increase of peroxide concentration in a month for diethyl ether in open-air, deithyl ether in a closed bottle, diethyl ether in a closed
bottle over sodium metal and diethyl ether in a closed bottle over sodium hydroxide).
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aga
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Welcome to the forum.
Why must it be a 2 year timescale ?
What happens in 2020 that we have not already forseen/ordained and/or planned for, where old diethyl ether will be of any use ?
It sounds like a silly question - if you know how to make it, just make it in 2020 and avoid the whole 'storage' problem.
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Apolo707
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| Quote: Originally posted by aga | Welcome to the forum.
Why must it be a 2 year timescale ?
What happens in 2020 that we have not already forseen/ordained and/or planned for, where old diethyl ether will be of any use ?
It sounds like a silly question - if you know how to make it, just make it in 2020 and avoid the whole 'storage' problem. |
I agree with you, but the thing is that I recently came across quite a good offer of diethyl ether (it is not found in my country as a starting fluid)
and I expect that I will completely use it up by 2020. Given the fact that shipping is expensive, I would like to order more so that I don't have to
constantly pay for the shipping. Also, I theoretically know how to make it from ethanol, but I am a little uncomfortable with the fact that the
reaction mixture is so close to the already low auto-ignition temperature of diethyl ether. I want it to last me 2 years because I expect to go to a
country in which I can get dichloromethane (in my country it is impossible to buy it as a civilian), which is mostly able to substitute ether, by
then.
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Apolo707
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Anyway, the end-goal for me is to have a non-polar, reasonably low-boiling (under 120 degrees centigrade or so) and reasonably non-carcinogenic
solvent that I can make/buy. Out of the common ones, chloroform and toluene seem good, but the first one is considered carcinogenic (though I don't
really know how bad it is), and the second one is very hard to separate from other solvents in paint thinners. So I would appreciate if anyone can
think of a good solvent, apart form the aforementioned ones, that falls into these categories and isn't an ester (those are too reactive).
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Magpie
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Prevention of peroxides is easy: add a little BHT.
I get my ether from starting fluid, which I know you can't get. Making it would be my next option.
[Edited on 26-1-2018 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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Apolo707
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| Quote: Originally posted by Magpie | Prevention of peroxides is easy: add a little BHT.
I get my ether from starting fluid, which I know you can't get. Making it would be my next option.
[Edited on 26-1-2018 by Magpie] |
So the BHT they include works well as long as the ether is in a closed bottle? Have you stored ether with BHT for prolonged periods without problems?
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happyfooddance
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Keeping it free from air, light, and in a cold place (i.e. freezer) also help significantly.
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Dr.Bob
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If the material is sealed well (best is factory sealed container), and not opened, kept cool, and out of light, it likely will be fine for 2 years. I
have used ether that is years old, but just tested it once I opened it. As a liquid, any dissolved peroxides are most dangerous if they form crusts
on the lid, due to a poor seal and evaporation, or if you evaoprate the liquid, leaving the concentrated peroxides. So the key is to just test it
before use (iodide starch paper is easy to make or buy), and just treat to remove if needed. Many reactions will actually destroy the peroxide, so
that is also handy. Just depends on the usage as to how critical any peroxides will be. But if you can buy it cheap now, it likely can be made to
last 2 years with minor care. I would not store over Na for long periods (you would need to distill it afterwards anyway), that is much riskier, some
NaOH might be OK, but best to just keep it tightly sealed, BHT is fine also.
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Magpie
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| Quote: Originally posted by Apolo707 |
So the BHT they include works well as long as the ether is in a closed bottle? Have you stored ether with BHT for prolonged periods without problems?
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Yes, no problems with ether peroxides. This also works for THF. I add it at 200ppm.
The single most important condition for a successful synthesis is good mixing - Nicodem
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Apolo707
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Thank you for your help! In conclusion, I should store the ether in a good quality opaque/brown bottle with a good cap in a dark cabinet with ~200ppm
BHT and check for peroxides with potassium iodide-starch paper before distilling. But I have a couple more questions: where did you get your BHT and
would you think that 'washing' with ferrous sulfate solution periodically would also help?
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ninhydric1
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BHT is available online as an "antioxidant supplement". Look on Ebay or Amazon.
The philosophy of one century is the common sense of the next.
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Apolo707
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OK. I found it at a reasonable price on ebay.
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byko3y
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I love seeing the same wrong information replicated over and over again by the book authors and just random people, despite the fact the correct
information had been long known.
AFAIK sodium hydroxide reacts with alkyl peroxides to form a sodium alkyl peroxide, which is stable and can be purified: https://books.google.com.ua/books?id=nCCGAwAAQBAJ&pg=PA1... In a long term that seems to be a good way for making a nice boom.
On the other hand, I'd say you are a victim of safety paranoia. For example, picric acid has never ever exploded in any laboratory, but the amount of
paranoia because of it is insane. Ethers did explode, but only after concentration (either intentional or incidental) or during attempt of peroxide
removal by some retarded chemist.
I have a bottle of ether that is more than 1 year old and was opened many times, yet I can barely detect small traces of peroxides with sodium iodide
somewhere on the edge of the sensitivity of the method, meaning less than 0.1 mg of peroxide in 1 ml of ether. So if I concentrate a whole 1 L of such
ether, I'd get approx 100 mg of explosive compound (maybe), which won't hurt much even if it explodes.
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symboom
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Whaaaat sodium alkyl peroxide I did not know that compound is possible,though alkyl peroxides are unstable this reminds me of isopropanol peroxide
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Magpie
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| Quote: Originally posted by byko3y |
On the other hand, I'd say you are a victim of safety paranoia. For example, picric acid has never ever exploded in any laboratory, but the amount of
paranoia because of it is insane.
I agree this is redickerous. I think the paranoia comes in because it is a primary explosive used for artillery shells during WWII, and may be still
used as such.
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The single most important condition for a successful synthesis is good mixing - Nicodem
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Bert
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I got a metal can of ether in the stuff an older man (who had done fireworks and explosives as a hobby for several decades) gave me when removing all
the chemistry supplies and "rendering safe" his house before going into a hospice due to untreatable cancer, he was a very clean old man. He had kept the ether in his freezer, next to his nitroglycerin for many years... No problems in storage so far.
I kept it another 8 years in MY freezer. Still no earth shattering kaboom- The can was kind of cool, I really should have taken a picture.
Finally, I noticed an ether smell when opening the freezer. The seal had died after God knows how long, probably 30 years or more. So I donated it to
the next bonfire. Still no earth shattering kaboom-
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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byko3y
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symboom, actually my sensitivity in detecting peroxides was order of magnitude lower because I used isopropanol as a solvent and it
gave a slight positive reaction before any ether was added. So probably my IPA contains traces of isopropyl hydroperoxide.
I've performed a quick search and was surprised to find a lot of info on the subject:
http://pubs.acs.org/doi/abs/10.1021/ja01264a512 - Peroxides in Isopropanol
https://cen.acs.org/articles/94/i31/Chemical-safety-peroxide...
https://chemistry.stackexchange.com/questions/4597/isopropyl... - Isopropyl alcohol forming peroxides
http://www.sciencemadness.org/talk/viewthread.php?tid=21495 - Subject: Isopropyl Alcohol (2-propanol) Peroxides
So you'd better start adding BHT to your IPA 
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Nicodem
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Thread Moved
27-1-2018 at 10:27 |
Apolo707
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| Quote: Originally posted by byko3y | I love seeing the same wrong information replicated over and over again by the book authors and just random people, despite the fact the correct
information had been long known.
AFAIK sodium hydroxide reacts with alkyl peroxides to form a sodium alkyl peroxide, which is stable and can be purified: https://books.google.com.ua/books?id=nCCGAwAAQBAJ&pg=PA1... In a long term that seems to be a good way for making a nice boom.
On the other hand, I'd say you are a victim of safety paranoia. For example, picric acid has never ever exploded in any laboratory, but the amount of
paranoia because of it is insane. Ethers did explode, but only after concentration (either intentional or incidental) or during attempt of peroxide
removal by some retarded chemist.
I have a bottle of ether that is more than 1 year old and was opened many times, yet I can barely detect small traces of peroxides with sodium iodide
somewhere on the edge of the sensitivity of the method, meaning less than 0.1 mg of peroxide in 1 ml of ether. So if I concentrate a whole 1 L of such
ether, I'd get approx 100 mg of explosive compound (maybe), which won't hurt much even if it explodes. |
At first, I wasn't very scared of peroxides, but when I read this article https://www.google.ro/url?sa=t&source=web&rct=j&... I changed my mind. Here it says that an unopened bottle of ether exploded even
though it was stored in a dark and cool place. You might say that this is an isolated case, but that doesn't mean that I shouldn't be scared of a
potentially explosive solvent which is also very flammable.
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S.C. Wack
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Ether used to be sold in cans that were re-sealed with a cork stopper. Copper lined cans. Cu detects too. Wire or shavings releases oxygen immediately
and obviously.
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byko3y
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Apolo707, explosion after 6 month storage is absurd to me. Diisopropyl ether? Maybe. You need to keep the bottle like really opened,
maybe stopper lying upside-down on the neck or whatever. 1 L of air contains roughly 9 mg of oxygen, which is nothing even if it reacts fully with
ether.
The following quote of a peroxide test procedure proves my suggestion about them having no idea what the talk and what they do:
| Quote: | | shake 10 ml of ether with 1 ml of fresh 10% (w/v) potassium iodide solution and a few drops of hydrochloric acid. Peroxides liberate iodine and the
aqueous phase becomes yellow. If the result is uncertain, add little starch siolution. A blue colour results from a trace of liberated iodine.
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First of all, that's an arbitrary modification of a rarely used general peroxide test, which cannot be applied to ether due to its immiscibility.
Probably they've picked this one because it provides the highest ether to water ratio. But this procedure will procduce most of the iodine in the
ether layer.
Second, starch does not produce blue color in the presence of ether. For this reason the KI-starch method was removed from many pharmacopoeias,
despite the fact starch actually rises sensitivity.
That highlights my point: those people are FUCKING DUMB, and yet they provide advises about something they don't know, that's why they work at some
school or colledge and not in a research facility. In the colledge nobody sees they are dumb, because other are even more dumber and can mix up the
labels, or leave the ether opened, or throw some dibenzoyl peroxide into the bottle, or god only knows what.
Not so long ago in some colledge there was an explosion of silver nitride that was caused by arbitrary modification of Tollens' reagent - those
assholes made very concentrated solution while being dumb, just like the ones that exploded ether bottle.
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Apolo707
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| Quote: Originally posted by byko3y | Apolo707, explosion after 6 month storage is absurd to me. Diisopropyl ether? Maybe. You need to keep the bottle like really opened,
maybe stopper lying upside-down on the neck or whatever. 1 L of air contains roughly 9 mg of oxygen, which is nothing even if it reacts fully with
ether.
The following quote of a peroxide test procedure proves my suggestion about them having no idea what the talk and what they do:
| Quote: | | shake 10 ml of ether with 1 ml of fresh 10% (w/v) potassium iodide solution and a few drops of hydrochloric acid. Peroxides liberate iodine and the
aqueous phase becomes yellow. If the result is uncertain, add little starch siolution. A blue colour results from a trace of liberated iodine.
|
First of all, that's an arbitrary modification of a rarely used general peroxide test, which cannot be applied to ether due to its immiscibility.
Probably they've picked this one because it provides the highest ether to water ratio. But this procedure will procduce most of the iodine in the
ether layer.
Second, starch does not produce blue color in the presence of ether. For this reason the KI-starch method was removed from many pharmacopoeias,
despite the fact starch actually rises sensitivity.
That highlights my point: those people are FUCKING DUMB, and yet they provide advises about something they don't know, that's why they work at some
school or colledge and not in a research facility. In the colledge nobody sees they are dumb, because other are even more dumber and can mix up the
labels, or leave the ether opened, or throw some dibenzoyl peroxide into the bottle, or god only knows what.
Not so long ago in some colledge there was an explosion of silver nitride that was caused by arbitrary modification of Tollens' reagent - those
assholes made very concentrated solution while being dumb, just like the ones that exploded ether bottle. |
The peroxide test did make me question their credibility as well, but it makes sense that they most probably lied about the conditions the ether was
stored in. There was no way that much oxygen made it into an never-opened bottle. Thanks for pointing it out to me that many cases of these incidents
are caused by people without any sort of common sense. Regarding that silver nitride explosion, I want to ask how is it possible that people who don't
know that this reagent can make silver nitride if it is too concentrated get to work with it in the laboratory. Wasn't there any professor with a bit
more knowledge that could tell those people not to concentrate the reagent so much? Even I, an amateur, know that ammonia and silver compounds can
make silver nitride.
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Apolo707
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| Quote: Originally posted by S.C. Wack | | Ether used to be sold in cans that were re-sealed with a cork stopper. Copper lined cans. Cu detects too. Wire or shavings releases oxygen immediately
and obviously. |
Do you want to say that copper catalyzes the decomposition of organic peroxides into oxygen and the original organic compound? If so, that could be a
very interesting method of preventing the accumulation of peroxides in diethyl ether.
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NEMO-Chemistry
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I have several 25ltr 99% IPA plastic drums, one is maybe 4-5 years old now. They are in the original containers, one is almost all used now, but i
have used it for distillations and extractions, because its big its sat in the shed in the day light. Hot in summer cold in winter.
I didnt know how serious the risk was, so I have never ever tested it! What really concerns me however, would peroxides mess up my extractions?
I doubt i will test them for peroxides, if they have them and i know, then i got to do something about it. Ignorance is bliss in this case. I 'might'
sling a little copper wire in though.
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