WalterB
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Registered: 1-12-2023
Location: FL black blotter
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shelf live LiALH4
HI.
Have LiALH4 over 5 years in metal can from supplier shelf life should be one year. Never opened, kept in two plastic bag filled with silica beads and
closed in other container filled also with silica, lid is crashed little bit down not sure if I did it or from decrease pressure inside. Wil be still
use able or its already bad? Do not want to open till I need it.
Thank you.
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Texium
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Ultimately the answer is “you won’t know until you try it.” I have seen reagents in those sealed metal cans be perfectly preserved until long
past their expiration date, and I’ve also seen ones that have degraded despite the can remaining visibly intact. When you do open it, you can run a
test reaction on something cheap to see if it is still active. My suggestion would be a reduction of methyl or ethyl benzoate to benzyl alcohol,
because it should only work if the LAH is active and it can easily be followed by TLC.
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WalterB
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Thank you Texium. I thought that just wanted to make sure. I guess I will learn something new. 
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woelen
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From my own experience I can say that LiAlH4 has unlimited shelf life if it is kept absolutely dry and no air cycling is possible.
I have some in a glass bottle with special seal inside a GL45 screw cap. That LiAlH4 is almost 10 years old and it is as good, as when I received it.
I also kept some in a small glass bottle, with an ordinary plastic screw cap. That LiAlH4 has completely degraded. The problem with most containers is
that there is cycling of air in/from the container. Hot weather, then air goes out, cold weather, then air gets in again. Each time, when there is
some cycling, also some water vapor get in, which reacts with the LiAlH4. If your seal is so good, that there is no thermal cycling of air, then the
LiAlH4 remains good.
The same is true for NaBH4, this also can be kept perfectly fine in a compeltely sealed bottle, but it slowly degrades in an ordinary bottle, due to
air cycling, leading to formation of NaBO2.xH2O in the long run.
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WalterB
Harmless
Posts: 5
Registered: 1-12-2023
Location: FL black blotter
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Mood: There's More Than One of Everything
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That sounds good due I never open the can and was filled under inert atm. Will post after open.
Thx to NL from ex CZ.
BTW if was you who did my registration good date of birth.
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