SHADYCHASE54
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Calcium pyruvate to sodium pyruvate or pyruvic acid
Hello all I was wondering if anyone out there might have any suggestions regarding the conversion calcium pyruvate to the sodium form. Would it be
possible to simply mix equal molar amounts of calcium pyruvate with sodium sulfate in aquous medium to thusly result in sodium pyruvate and calcium
sulfat most of which should precipitate? Then seperate the remaining calcium sulfate via fractional crystalization. If someone knows a reason that
this will not work could you please offer an alternate procedure. I realize I could simply acidify the calcium pyruvate and fraction the pyruvic acid
under reduced pressure, however what would be a suitable solvent for this procedure? I appreciate any responces and thank you all for your thoghts.
SHADYCHASE54
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unionised
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It would work but Ca SO4 ppts are notoriously sludgy and hard to filter. Try using Na2CO3 solution and ppt the Ca as CaCO3.
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SHADYCHASE54
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Thanks unionised for your suggestion, however I am now more interested in obtaining the free acid. I was thinking of using oxalic acid to acidify as I
would be left with hopefully the pyruvic acid and the calcium oxalate, calcium oxalate being almost totally insoluble in aqueous solution. As a result
it would seem that the final work up would be a breeze. Is this assumption correct? The reason I ask is that I rarely hear of acidification of calcium
salts with oxalic acid and I just wondered if maybe there was a reason that I was unaware of? I just wanted to know before potentially wasting my
chems. Obviously I will try it anyway but I always like as much info. as possible before hand. Thanks alot to anyone whom replies with a suggestion.
Shadychase54
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scientician
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I do this all the time, (oxalic acid and aq. calcium pyruvate.) It does work quite well, but I tend to use mine for bioassays. Calcium oxalate is
nasty shit, I don't recommend you ingest it.
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Organikum
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Wont the pyruvic acid/pyruvate polymerize or form other unwanted products when treated with sodium carbonate or even oxalic acid?
Literature and patents always mention this to happen.
For a quick experiment some grams of commercial calcium pyruvate were mixed with a slight excess of sodium carbonate in hot water.
There is a fallout which seems to be calcium carbonate but another layer of more mobile fallout.
Also the liquid tuned to the color of urine and this is for me often a sign of polymerisation taking place.
Any comments, ideas, flames?
/ORG
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Mesa
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Quote: Originally posted by Organikum  | Wont the pyruvic acid/pyruvate polymerize or form other unwanted products when treated with sodium carbonate or even oxalic acid?
Literature and patents always mention this to happen.
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If you are going to make a statement like this, provide at least one reference. It's not very difficult.
@OP: UTFSE
http://www.sciencemadness.org/talk/viewthread.php?tid=8560
[Edited on 26-9-2013 by Mesa]
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madcedar
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It seems like pyruvate salts have to be kept cold in order to get them behave. This is what our great-grand fathers had to say about it:
From: A Treatise on Chemistry by Roscoe & Scholemmer, Volume 3 Part 2 page 155
| Quote: |
The salts which are termed pyruvates or pyroracemates, crystalize only when they are prepared in the cold. When their solutions are
heated they pass into gum-like masses. These have been chiefly investigated by Berzelius, and the following are the most characteristic. Sodium
Pyruvate, C3H3O3Na, crystallizes in elastic prisms or tables, and is almost insoluble in alcohol. Calcium
Pyruvate, separates out in crystals on evaporating its solution in the cold. If warmed even by the hand a gum-like mass is produced.
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[Edited on 26-9-2013 by madcedar]
[Edited on 26-9-2013 by madcedar]
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Organikum
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Your link provides no answers to my questions and your request to be pointed to Wikipedia or any other source of common chemical knowledge, well, I am
not in the mood for babysitting, so no, thanks. 
@ madcedar: I will repeat the test in the fridge using cold water and report results. Thx.
regards
/ORG
[Edited on 27-9-2013 by Organikum]
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bfesser
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<strong>Organikum</strong>, he's right on one thing; if you say something like "literature . . . always mention[s] this to happen," then
you should provide at least one example.
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Mesa
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| Quote: Originally posted by Organikum |
Your link provides no answers to my questions and your request to be pointed to Wikipedia or any other source of common chemical knowledge, well, I am
not in the mood for babysitting, so no, thanks.
@ madcedar: I will repeat the test in the fridge using cold water and report results. Thx.
regards
/ORG
[Edited on 27-9-2013 by Organikum] |
My response to your post was unintentionally rude. Sorry about that. I was frustrated for reasons unrelated to this thread(which, incidentally, you
helped me out with in another thread. Thanks!)
That being said; prior to posting that response, I had already performed a cursory search for polymerized products from pyruvic acid on Wikipedia and
Orgsyn, before realising that it was stupid for me to waste my time researching a claim someone made with no supporting evidence.
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Organikum
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| Quote: Originally posted by bfesser | | <strong>Organikum</strong>, he's right on one thing; if you say something like "literature . . . always mention[s] this to happen," then
you should provide at least one example. |
Just look at my name. I am literature!.
Problem solved.
....................................................
I read the FAQ, I post here since the dawn of times and what you say is just your personal opinion and no rule at all.
If somebody does not know about the problem the thread is uninteresting for him. if he knows, he has not to be told. Period.
And its still amateur experimentalism and not the embarassing try to copy the style of scientific articles (what you would like us to
do, as we know), we are not all Bariums, porn-actors playing research chemists.....
Actually I wanted to post some preliminary results, but this takes the fun out of it, for you two last posters turn whats supposed to be an relaxed
exchange of ideas and knowledge into homework.
Nobody likes homework.
Maybe another time.
/ORG
@madcedar: thx again, the spirit still lives, thats good to see 
[Edited on 28-9-2013 by Organikum]
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bfesser
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Thread Pruned
28-9-2013 at 05:46 |
bfesser
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You can say whatever you like. But if you want it to be taken seriously, it's best to support your statements with evidence in the form of lit.
references. If you want to act a spoiled child about it, go right ahead; I won't interfere further—I was simply making an observation.
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Mesa
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Organikum; the reason for my initial post asking for a reference was because I've never encountered such polymerization in very similar experiments
attempting to produce H2O2 by decomposing pyruvic acid with sunlight+catalyst. Pyruvic acid was obtained from calcium pyruvate and oxalic acid,
again, without polymerized products.
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Organikum
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| Quote: Originally posted by Mesa | | Organikum; the reason for my initial post asking for a reference was because I've never encountered such polymerization in very similar experiments
attempting to produce H2O2 by decomposing pyruvic acid with sunlight+catalyst. Pyruvic acid was obtained from calcium pyruvate and oxalic acid,
again, without polymerized products. |
Thats interesting.
As told before I tried to convert calcium pyruvate into sodium pyruvate by the suggested method of adding sodium carbonate. This gave a strong yellow
discolorisation if stochiometric or more carbonate was applied, only if considerable less then the stochimetric amount was used this was tolerable.
From what I know and by experience I judge this to be very probably polymerisation.
Of course it is very well possible that an acidic environment is much more suitable and far less problematic, its true for most ketones and aldehydes
so why not here.
I have some calcium pyruvate left and finally aquired oxalic acid, so I will do some experiments the next days and post results. Not that I doubt that
it works for you, so I pray it will for me too - or at least I am able to find out what I botch and can correct it.
One minute Google gives me this:
http://www.uni-ulm.de/physchem-praktikum/media/literatur/193...
Quote, page 593: "As is well known, pyruvic acid easily polymerizes upon standing ;"
I somewhat see it not necessary to reference stuff wellknown since a hundred years, I will refrain from doing so also in future, as wellknown stuff is
to look up by oneself or it gets endless.
Additionally about every patent on biosynthetikal pyruvic acid production and most contemporary patents on calcium or sodium pyruvate production
emphasize on the problem, I remember to have read an austrian one which pretty much did away with most very old methods (including anylysis of the
results) proving that they produce mostly polymeres or form rings but rarely the wanted pyruvate. Includes the dehydration by glycerol too, the fist
method of all as I think. Threy just had not the analytical possibilities then in the end of the 19th century and lateron.
Well, I have to try something now.
/ORG
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zed
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Somewhere, probably here, there is a procedure for producing Pyruvic Acid from Tartaric acid.
It isn't hard.
http://www.orgsyn.org/demo.aspx?prep=cv1p0475
[Edited on 26-11-2013 by zed]
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Organikum
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A horrible reaction for the true masochist.
Low yielding too.
/ORG
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zed
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Your opinion has been noted.
The materials are dirt cheap, and readily available OTC, at least here in the U.S..
Also, my experience with OrgSyn. procedures has been that they work well. They won't publish 'em if they don't.
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biojammer
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Hold on a second... Organikum said, "I tried to convert calcium pyruvate into sodium pyruvate by the suggested method of adding sodium carbonate. This
gave a strong yellow discolorisation... and by experience I judge this to be very probably polymerisation."
Sodium pyruvate is (bright urine) yellow in solution.  I don't know if the
reaction was successful, but it certainly sounds good. But I'm skeptical because Calcium Pyruvate is essentially insoluble.
With regards to stoichiometery... Ca(Pyruvate)₂ + Na₂CO₃ --> 2 NaPyruvate + CaCO₃
To test: filter and rinse the proposedly formed calcium carbonate. Then add vinegar to the CaCO₃... CaCO₃ will not bubble by adding vinegar
(whereas Na₂CO₃ will bubble). Then try a few drops of 10% HCl... CaCO₃ will bubble vigorously. If you have indeed made CaCO₃, please let me
know. I wish I had some calcium pyruvate to try this; especially since the price for Na pyruvate is about $1/g whereas Ca pyruvate is about $0.05/g.
Such an easy method for convertion of Ca to Na would be money-mental.
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zed
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Wow, a really dead thread. More than five years old. What I didn't realize at the time, was that Calcium Pyruvate has become cheap and available, as
a supplement.
In my youth, Pyruvic acid was a material I could not buy. Useful, but unavailable.
Gotta agree, I would not make it, nowadays.
BulkSupplements.....
https://www.bulksupplements.com/products/calcium-pyruvate-po...
[Edited on 16-1-2021 by zed]
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Boffis
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As pointed out above by several posters calcium pyruvate is now a fairly readily available food supplement and therefore a potential source of pyruvic
acid. The other routes to pyruvic acid such as the distillation of tartaric acid with sodium bisulphate or by the hydrolysis of αα-dibromopropanoic
acid are either just awful in the first cause or require a hard to obtain starting material as in the second route. I recently required a modest
quantity of pyruvic acid and since it didn’t need to be anhydrous, I decided to investigate the recovery of pyruvic acid from its calcium salt. I
couldn't find a good procedure on either the SM web sit or in the literature for this process so I decided to carry out a few experiments of my own.
The calcium salts comes as a fine, off-white powder so I first decided to investigate its solubility and its recrystallisation. I quickly discovered
that the salt is rather insoluble in water though when added to boiling water it slowly dissolves but doesn’t crystallise on cooling; instead,
colourless gelatinous lumps form. Even traces of alkali or alkali carbonates cause rapid yellowing, particularly on warming and this reaction has been
extensively studied, the eventual product, though not in great yield, is uvitic acid (5-methyl-isophthalic acid). Pyruvic acid seems more stable
towards dilute mineral acids and I have found that the free acid is readily liberated from the calcium salt by dilute sulphuric acid.
In order to determine the amount of acid actually liberated I decided to analyse the product. There are several proposed methods for the determination
of pyruvic acid in the literature but the one that caught my attention was a method utilising the condensation of pyruvic acid with o-phenylenediamine
to give 3-methyl-2-quinoxalone, this reaction therefore, appears to be practically quantitative. The method I based my procedure on used a
polarographic technique to measure the formation of the quinoxaline but I have adapted this technique to a gravimetric method whereby the quinoxaline
is filtered off and weighed. It appears that the yield of pyruvic acid from calcium pyruvate is at least 92%. I have used this figure in my subsequent
experiments to estimate the yield of the various derivatives that I have prepared.
The preparation of Pyruvic acid from Calcium Pyruvate
53.530g of commercial calcium pyruvate was dispersed into 100ml of water in a 250ml beaker equipped with a magnetic stir-bar. With vigorous stirring
50ml of 5M sulphuric acid were run-in over about 1 to 2 minute. After the addition of about 40ml the suspension suddenly gelled and manual stirring
was required for a brief period but with continued addition of the sulphuric acid the slurry thinned again, allowing the magnetic stirring to
continue. Once the addition of sulphuric acid was complete the cream coloured suspension was stirred for about 15-20 minutes and then chilled to 4°C
for an hour.
The suspension is vacuum filtered using a Buchner funnel, just as the cake starts to look dry but before it cracks 25ml of water were poured over and
drawn through the cake to remove most the residual acid. The cake was sucked as dry as possible, healing any cracks with a spatula. The cake is gypsum
and can be discarded. The filtrate is about 148ml and contains 0.46 Moles of pyruvic acid.
Analysis of pyruvic acid extraction from Calcium Pyruvate
2.147g of calcium pyruvate were dispersed into 10ml of water and 5ml of 5M sulphuric acid added. The suspension was stirred for 10 minutes and then
vacuum filtered. The cake was washed with 5ml of water.
2.155g of o-phenylenediamine were dissolved in 15ml of warm methanol and then slowly added to the vigorously stirred pyruvic acid solution; a pale
yellow precipitate formed rapidly. The filter flask and the beaker used for the diamine solution preparation were each washed with 5-7ml of methanol
and the washings added to the reaction mixture. The mixture was warmed for 15minutes to no more than 50°C and cool. Filter off the pale yellow solid
that has formed, wash with a little 50% methanol and dry. The yield was 2.943g of crude 3-methyl-2-quinoxalone; 91.9% of theory.
NB the amount of o-phenylenediamine used was equivalent to a 100% yield of pyruvic acid, a larger excess causes problems by precipitating with the
quinoxalone derivative.
No attempt was made to recrystallise the crude quinoxalone derivative as this would result in further losses. Some quinoxalone must remain in solution
but the high recovery suggests that the amount is small. Evaporating down the filtrate to half volume did not result in further quinoxalone being
deposited. The solution became cloudy and a little oil separated.
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