netnofeels
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Whats the best way to obtain Sodium Bisulfite NaHSO3?
I need it for the final step of a experiment im doing. It will be used for forming bisulfite adduct with the aldehydes so that I can purify it. The
thing is I cant seem to find this at a decent price anywhere in the uk.. And when you search for it pretty much sodium bisulfate is the only thing
that appears. To the experts what would be the best way to obtain sodium bisulfite?
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j_sum1
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Sodium metabisulfite is functionally the same thing once dissolved.
Youtuber, Shiva chemist released a video just this week showing synthesis of sodium bisulfite.
That should get you there.
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netnofeels
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Quote: Originally posted by j_sum1  | Sodium metabisulfite is functionally the same thing once dissolved.
Youtuber, Shiva chemist released a video just this week showing synthesis of sodium bisulfite.
That should get you there.
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Thanks its hard to find small youtubers like that but ill add him to the list! Are you saying I could use Sodium metabisulfite to form bisulfite
adduct with the aldehydes the exact same way that sodium bisulfite does it? If so that would be great but how?
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Heptylene
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@netnofeels: I have extracted cinnamaldehyde from cinnamon bark oil by making the bisulfite adduct. I used sodium metabisulfite and it worked fine. If
you want to be certain you can try it on a small scale first.
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netnofeels
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| Quote: Originally posted by Heptylene | | @netnofeels: I have extracted cinnamaldehyde from cinnamon bark oil by making the bisulfite adduct. I used sodium metabisulfite and it worked fine. If
you want to be certain you can try it on a small scale first. |
Ok great. What made you think that would work okay?
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Heptylene
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Apparently you have an equilibrium between metabisulfite and bisulfite in water: Na2S2O5 + H2O <-> 2 NaHSO3. I couldn't find a decent reference
for this however.
I first tried it on a small scale: added metabisulfite solution to cinnamon oil in iPrOH. Heated for 30 min, filtered, washed, dried. The product was
hydrolyzed to a cinnamon smelling compound.
I then used the rest of the cinnamon oil (100 ml) and processed it in the same way. I hydrolyzed it and had enough to measure the density of the
product, which matched that of cinnamaldehyde.
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netnofeels
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| Quote: Originally posted by Heptylene | Apparently you have an equilibrium between metabisulfite and bisulfite in water: Na2S2O5 + H2O <-> 2 NaHSO3. I couldn't find a decent reference
for this however.
I first tried it on a small scale: added metabisulfite solution to cinnamon oil in iPrOH. Heated for 30 min, filtered, washed, dried. The product was
hydrolyzed to a cinnamon smelling compound.
I then used the rest of the cinnamon oil (100 ml) and processed it in the same way. I hydrolyzed it and had enough to measure the density of the
product, which matched that of cinnamaldehyde. |
If this would work I'd be mixing the crude aldehyde I have atm with excess saturated aqueous sodium metabisulfite solution for several hours,
filtering the solid bisulfite adduct, washing with ether, and liberating the aldehyde with excess aqueous sodium bicarbonate. Then distilling to give
pure aldehyde
I am at the end of a experiment ive been doing and really dont want to mess it up. Do you think this will work ok?
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Heptylene
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Which aldehyde is it you want to purify exactly? Without that information I can't tell you anything.
Why don't you run a small scale test? How much product do you have to purify?
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netnofeels
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| Quote: Originally posted by Heptylene | Which aldehyde is it you want to purify exactly? Without that information I can't tell you anything.
Why don't you run a small scale test? How much product do you have to purify? |
I sent you a message mate
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Jimmymajesty
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NaHSO3 can be prepared by burning sulphur in a can, sucking the SO2 into Na2CO3 solution in a wash bottle till it smells of SO2.
Actually I made ~700ml saturated NaHSO3 solution today as above.
Reason is that K2S2O5 is rather expensive, I can buy 3kg sulphur or 2kg Na2CO3 for the price of one kg PMB.
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PirateDocBrown
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I got mine at a photo supply store. Those are getting scarce these days!
Phlogiston manufacturer/supplier.
For all your phlogiston needs.
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woelen
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As far as I know, solid sodium bisulfite does not exist. The product they sell as bisulfite is the metabisulfite. In aqueous solution bisulfite is
present as ion, but when the solid crystallizes, two bisulfite ions condense into a metabisulfite ion:
HSO3(-) --> S2O5(2-) + H2O
In aqueous solution this ion is mainly present as bisulfite, in solid form it exists as metabisulfite. The metabisulfite ion, according to some books,
is not an [O2S-O-SO2](2-) species, but an [O2S-SO3](2-) species, with a direct S-S bond in the ion. It is an adduct of SO2 to SO3(2-).
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