Author Topic: Extracting H3PO3 from phosphite foliar solutions  (Read 18741 times)

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halfkast

  • Guest
Extracting H3PO3 from phosphite foliar solutions
« on: August 28, 2003, 10:00:00 AM »
Disclaimer:
!!!!!!!Educational and informational purposes only!!!!!!!!!!!!!!!

I won't bee held leagally responsible for this cause i don't wanna, but i wanna give it beecause i just wanna. Check your localz laws, if its illegal where you are then its the authors opinion that you should move houses before saving.
Its for educational purposes and i include warnings throughout loud and clear about the dangers.


Objective/Aim:

To isolate H3PO3(s) from an aqeous solution of it's phosphite salt(s), mono/di-potassium phosphonate.


Important numbers & Formulae


H3PO3     = 81.996 g/mol
K                = 39.098 g/mol
KCl            = 74.551 g/mol
H2O          = 18.015 g/mol
KOH         = 56.106 g/mol
HCl           = 36.461 g/mol
KH2PO3 (Mono-potassium phosphonate) = 120.086 g/mol
K2HPO3 (Di-potassium phosphonate) = 158.177 g/mol


This section is simply an analysis of the best and worst case scenarios as far as what the theoretical potential  yields actually are. You can read over this section if you wish or skip to the procedure further down...

HClmin is simply a theoretical quantity I made up to denote the amount of HCl that would be used up during the reaction and required by the procedure if the feedstock contained only the mono-K phosphonate form an unlikely event maybee... but nevertheless I think you'll find the information convenient when weighing your final yield as this quantity represents the upper potential theoretical yield for a given amount of the potion of phosphites.

The HClmax quantity has a more procedural significance...it represents the amount of HCl you'll actually measure out to guarantee a complete reaction whatever the proportion of mono/di-K forms in your foliar solution, specifically it simply assumes that it all contains only the Di-K form – The least phosphorous acid rich form, but this reaction requires more HCl.

Your actual yield will fall between them both, so from 40g, 100ml of 400g/L foliar potion you should get between 20-27g of H3PO3.
If you measure more than 27g, that's great, it just means that you are measuring a little H2O impurity most likely. If you weigh <20g your lab work needs work or your supplier does, because he is a con.

Analysis of HClmin and HClmax reactions and the theoretical outcomes


Quantity analysis of.: HClmin:
 
Formula
KH2PO3
(40g, .33 mol) + HCl(12g, .33 mol) ---> KCl(24.83g, .33 mol) + H3PO3(27.3g, .33 mol)

Reactants
KH2PO3  =     40g, 100ml@400g/L
HCl     =     12.145g, 40.48ml@0.3g/ml

Resultants and theoretical quantities of
KCl     =     24.83g
H3PO3   =     27.31g



Quantity analysis of.: HClmax:
 
Formula / Quantities
K2HPO3(40g, 0.25mol) + 2 HCl(18.44g, 0.5mol) ---> 2 KCl(37.5g, 0.5mol) + H3PO3(20.7g, .25mol)

Reactants
K2HPO3  =     40g, 100ml
HCl     =     18.44g, 61.46ml@0.3g/ml

Resultants and theoretical quantities of.:
KCl     =     37.5g
H3PO3   =     20.73g


Materials & Chemicals

Equipment
Electric fry-pan sand/oil-bath or hotplate (no COILS)
Table salt* if you use a hotplate. No oil/sand required
Glass Pyrex boiling jug
Empty wine or champagne bottle
Glass Pyrex tray or suitable casserol dish
Squeezable squirting bottle
Plastic scraper or any plastic object with a flat sharp edge
Fan-forced oven
Kitchen plastic wrap
Pestle – no mortar is needed
Reasonably good ventilation


Chemicals
Methylated spirits a.k.a denatured alcohol (simple, vaguely accurate names for simple, rarely accurate people...Yeah pick on ther yanks when life is going badly for ya, thats fine!)
Foliar spray containing aqueous di-potassium phosphonate and mono-potassium phosphonate salt (phosphites)
300g/litre (8.22M) HCl or muriatic acid
Distilled water; but springwater is fine.



Abstract of procedure
1.Measure 100ml of 400g/litre potassium phosphite solution
2.Measure HClmax solution
3.Add diluted  HClmax solution to diluted potassium phosphonate solution; wait
4.Boil off H2O
5.Refrigerate resultant concentrate
6.Extract [and, decant off] 3-5 times using cold methylated spirits
7.Boil off alcohol and H2O
8.Repeat Steps 6-7
9.Transfer to a large shallow glass pyrex dish
10.Heat until relatively anhydrous using 70-90C temperatures
11.Cover and cool your H3PO3 using a freezer
12.Transfer to a permanently air-tight container to bee buried  8)


Example of procedure


///HUGE WARNING///: PH3 IS PRODUCED UPON DECOMPOSITION OF H3PO3 AT 180C, ENOUGH TO KILL YOU AND PROBABLY ALSO ANYONE WHO ATTENDS TO YOUR LIFELESS BODY.  :)


1.Carefully measure 100ml of a 400g/L potassium phosphonate foliar solution and transfer to a wine or champagne bottle that can accommodate both this solution, aswell as the HCl which will be added. Dilute this with 100-200ml of DH2O.
Leave nothing behind in your measuring instrument, not a trace, cover your tracks using warm water.

2.With good ventilation present, carefully measure 61.50ml of 8.22M(300g/L) HCl solution, carefully dilute this with 200ml of DH2O. Store this in a suitable bottle

3.Using a funnel, add this dilute HCl solution to the wine bottle containing your phosphite salts in 5-10 increments over the course of 1hr, swishing the wine bottle around in a circular motion as you do this to ensure a complete reaction. 
Continue this until all of your dilute HClmax solution has been added to the wine bottle...which now contains H3PO3(aq), KCl(aq) and any excess HCl that wasn't used in the reaction due to the presence of mono-phosphonate salt form.
Shake and settle this reaction mixture for 1-3hrs.

4.Transfer the contents of your wine bottle, a cloudy white H3PO3(aq), KCl(aq) [,and any excess HCl(aq) ] mixture, carefully to your glass pyrex jug.
Cover your tracks from the wine bottle using a generous amount of warm-hot water and add this to your pyrex jug aswell.

5.Pour a generous amount of table salt on your hot plate, (not on coil ones ;D ) to protect the jug against the direct heat. But any type of oilbased sandbath is suitable, even prefered.
Place the pyrex jug on your chosen heating medium and bring to a boil gently and maintain over the course of a few hours or until you begin to see salt (KCl) precipitate. This just indicates that your H3PO3(aq), KCl(aq) mixture has now reached a point where there isn't enough room for them both..and of course the H3PO3 wins that battle allday everyday being strongly hygroscopic and deliquescent-so the KCl(s) is precipitated.
Remove the jug from the heat and allow to cool – Use the refrigerator when you feel it is safe to do so. Make it cool-cold before the next step.
Note: This step has the biggest question mark over it...the more you boil off the better as far as removing the KCl in this step, but it might also reduce your H3PO3 yields. Late brainstorm! It probably won't decompose in the presence of water, but boil the shit out of it at your own risk.

6.Add methylated spirits to this cold solution in tiny increments-you will notice more KCl precipitating out, as the KCl has yet another substance to compete with which it isn't soluble in to any great extent. Continue adding the methylated spirits until no further KCl is being precipitated. Add some more methylated spirits, you can't overdo it.
Note: Keep in mind that this reaction produces a LOT of KCl, so removing it early on is highly preferable or it is likely to trap H3PO3.

7.Carefully pour off this now much purer (though it still contains some KCl(aq)) alcoholic aqueous solution of H3PO3 in to another large jug.
For good measure use your squirt bottle to wash down the inside of the jug. Get a pestel and grind the KCl(s) for the 2nd and 3rd pulls so that it releases any H3PO3 in to the methylated spirits.
Transfer it back in to your (WELL RINSED) boiling jug
Note: Either keep the KCl or throw it away or save it for a nano maybee later. But it probably doesn't contain much phosphorous acid.

8.Repeat Steps 6 and 7. But don't expect to see much if any KCl precipitate out while boiling, your more likely to see it when adding the methylated spirits.

9.Now boil down this aqeous alcoholic H3PO3 once more to a cloudy white (maybee a hint of yellow) concentrate.


10.Pour this carefully in to your pyrex evaporation dish. Place in the oven on the very top shelve, with your fan force on, and the DOOR SLIGHTLY OPEN THROUGHOUT THIS STEP(!!), use a 70-90C heat.
Note: I know it takes a long time but you have to wait. Check it regularly, shine a torch across the liquids surface and tilt it to see how it's going.
When the H3PO3's ready it will STILL BEE A LIQUID, BUT SLIGHTLY VISCUOUS AND SYRUPY, it's melting point is 70C so it'll bee obvious when the ethanol and H2O has gone.
Prepare a big section of plastic kitchen wrap with a sache of drying agent taped to one side. The drying agent isn't necessary, but it will absorb any steam coming off the hot H3PO3...if you don't use it you'll still have the wax.
11.Carefully take your evaporation dish of delicious smelling phosphorous acid out of the oven, and plastic wrap it carefully (no air leaks!).  Place in the freezer. Come back in 30min-1hr and as you can see you are the owner of Excellent-Whoa! PHOSPHOROUS ACID!

12.Use plastic to transfer the goodies...do it in the freezer, the freezer is dry and cold. Weigh the shit. You did good. It's not meth but you can pretend! This shit is reagent grade man, I'd bet my dick on it.

Discussion

The procedure produces a white-yellow pleasant-smelling waxy solid strongly suspected to be made up of predominantly the compund H3PO3 (phosphorous acid) in excellent yields.


Yield
90% yields are quite do-able, of course you'll never know but during testing mine were closer to the HClmin theoretical so I know I probably got close..

If you use the basic lab technique of “covering your tracks” with a solvent that dissolves your desired end product, and carries it from every surface it touches during the procedure to the end-point of the procedure – the freezer.

Don't have any spills. So, think about what your going to bee forced to pour out of. If you have a spill, the work you've put in to covering your tracks seems worthless.

Quality
i.e. H3PO4, Other impurities, Hydration.


There may well bee a small KCl impurity at the end, certain steps repeated will reduce this, with no expense to yield as for example with maybe boiling a concentrated aqeous solution of H3PO3 and KCl.
The use of cold OH really helps with the KCl impurity. Small pulls/extractions also helps because of reasons Rh explained recently in the Solvent Miscibility chart sticky thread in the Newbee forum (where I belong)

HCl impurity will bee near non-existant, the addition of the ethanol may even cause some formation of ethyl chloride with any excess HCl, and bee burnt off during the second boil. Either that, or it is fumed off at the final evaporation in the fan-forced; one of the final steps.
So in one sense, the more excess HCl there is the better, because it means that your solution wasn't entirely made up of the less phosphorous acid rich di-K phosphonate salt.


Worried about H3PO3 impurity? So was I, because at one point I had only seen it as a frozen solid, so to test it I heated the container to about 30C+ in front of the heater. There was only a very small amount of liquid, very insignificant, the vast bulk of it remained a firm solid. I do mean tiny amounts too, not ¼ of it swishing around, I'm talking minute amounts! -1% visually. This is shit that was from a traumatic test procedure I spent days carefully drying.

Keep it in a cold place, as cold as possible, I doubt it will oxidize much at all.

Novel quickies

Okay so the problems associated with this substance as you all probably know are natural oxidation of the substance in the presence of free oxygen(1), drying(2); and the problems this causes for measurment as a reagent(3). So these are what the novel ideas are mainly focused at attempting to solve.

1.Funnel molten h3po3 into PVC tubes or sticks or a large syringe.
2.Add a sache of activated carbon to your container to keep O2 levels down.

Other possible uses
1.Drying agent?
2.A new waterless A/B ingredient?


Conclusion

Using this procedure the waxy solid phosphorous acid (H3PO3(s) can be easily extracted and isolated from an aqeous solution of it's phosphite salt(s), mono/di-potassium phosphonate.
The yields are excellent, the quality although untested in a HI reaction to any extent whatsoever should be quite suitable for the said reaction.
I'd really like a simple way of testing purity, and/or isolating either the phosphoric or the phosphorus acid, but we don't always get what we want...in a reasonable timeframe.

If you need help converting any numbers or concentrations or anything just let me know and we can edit it in to the write-up for future reference. This includes internationalisation of anything.

Best of care,
halfkast

hellman

  • Guest
Wow!
« Reply #1 on: August 29, 2003, 06:25:00 PM »
This is more like it,
Could you possibly pm me and tell us where we find this ambibenevolent foliar spray?,

Great post, fucking great,
Ok, monkeys get to work,

hellman ;)


Lucid_Dreamer

  • Guest
I've been patiently waiting...
« Reply #2 on: August 30, 2003, 01:25:00 PM »
Thank goodness, I was beginning to think I was going to have to post a write-up on this, very nice BTW.

And hellman, if you aren't finding phosphite foliar sprays for disease and fungicide control and prevention then you aren't looking hard enough. They are being used all over the world. The only reason they aren't trademarked and copyrighted is because of some major law suits between two companies who are about to release them here in the U.S. They are however, being sold in some states currently. There are endless posts on the where, when, and how of the foliar phosphite sprays, how could you have missed these unless your search engine finger is broke?


BOS

  • Guest
Kudos to you my friend.
« Reply #3 on: August 31, 2003, 12:23:00 AM »
Kudos to you my friend.
I was beginning to think no-one had the ballz to post a write-up on this magical spray.
I would have,but Ive never tried it-this must change,now I have got meself a recipe. :)

Nice write up cob.

All the best,
Ballzofsteel.

halfkast

  • Guest
Your all welcome of course
« Reply #4 on: September 03, 2003, 03:52:00 AM »
I think it could bee better, it's childishly written but it's functional and pending reaction testing I think that the quality of the product is excellent.

I've been busy for a few days, that's why I haven't returned to hive responsibilities sooner

There's no need to feel anxious about the PH3, I say this because it is safer that you check it regularly and touch the glass, 180C hurts a lot more than 100, faster!
Rotate the glass evap dish if you feel the need too, either because you want to bee ultra safe about the temperature of every part of it or just because it helps distribute the remaining liquid better.

ALSO remember to use your squirt bottle around the inner sides of both your boiling jug as the solution level lowers to wash off any H3PO3, and also do the same with the oven bake evap dish; just so it remains in solution.


In the actual procedure remember to use cold alcohol, it's missing in the write-up procedure, but it is written in the abstract of.

hellman, thanks a lot. I'd love to but I can't, where are you from? I'm sure it's easy to find in google man come on.


BoS hehe well tell me how it goes okay. especially tell me how it goes in a reaction but all feedback is excellent.

hellman

  • Guest
shit, what the fuk is this, repost if necessary
« Reply #5 on: September 03, 2003, 05:51:00 PM »
I just found this, on some chinese site,
i am sorry to post it here:

this was the site:

http://science.2ch.net/test/read.cgi/bake/1000375229/l50



If this is indeed true, i would be proud, but i have to go,..

15 ml benzene, 15 ml acetone, 25 ml AcOH and 5 mmol(1,01 g) Mn(AcO)3
are boiled under N2 atmosphere until the color of the soln changes from dark brown Mn(AcO)3 to pink Mn(AcO)2 - approx.
1,5 h. The rxn mixtr is diluted w/40 ml ether, washed w/25 ml water and 2x25 ml 5% NaHCO3,
the org layer is dried and evap'd to yield 40% phenylacetone(134 mg)

FOAF


abolt

  • Guest
Fester
« Reply #6 on: September 03, 2003, 09:27:00 PM »
Fester published that synth., years ago.


raffike

  • Guest
It might work but that manganese salt is ...
« Reply #7 on: September 04, 2003, 08:31:00 AM »
It might work but that manganese salt is expensive to say at least.


halfkast

  • Guest
I can't wait
« Reply #8 on: September 04, 2003, 10:12:00 AM »
for your 3 texturous shitstains to bee scraped up, but the unmistakable brown aftermarks will remain unfortunetly...

halfkast

  • Guest
flashing out impurities note
« Reply #9 on: September 09, 2003, 12:54:00 PM »
1. If you are left with a froxen product that is too yellow for your liking, try this... Take the sealed container out of the freezer warm it in front of the heater.
Refreeze it, it should look slightly different, I don't know exactly why, maybe it's just ice.
Anyway now add room temp methylated spirits to the frozen H3PO3 and swish it around and let it settle until the methylated spirits is yellow...the H3PO3 should bee pure white now, and more flakey.
Discard the yellow Metho.
It works just like geezmeister would do an acetone flash, but you can use more metho here, the frozen H3PO3 doesn't dissolve as freely as you (and I) might think, as you can see (when you do it).

That leads on to another small issue.
I wasnt very specific with the temperatures..How much exactly to cool down to, and the temperature of the OH.
That's because it doesn't matter a great deal, I just want to make sure it turns out pure. The KCl really doesn't like dissolving with H3PO3, some water, and a dispropportionatly large amount of OH...whatever the temperature, as long as it is = or < room temp.

Its unfuck-UPable, the flashing note up there works really well if anything does happen to make it through.

mickyfinn

  • Guest
Requiem for a phosphonate...
« Reply #10 on: September 10, 2003, 12:06:00 AM »
I attempted to get help with this a few months ago but to no avail...

Post 440905

(mickyfinn: "phosphonate solution for H3P03 reflux", Stimulants)


A little birdie once told me in a PM that reagarding O-Ethyl Hydrogen Phosphonate:

Phosphorous acid is also called Phosphonic acid.
All salts of Phosphorous acid are called Phosphites and are commonly called Phosphonates. They are all one in the same.

O-Ethyl Hydrogen Phosphonate fungicide:
Mix about 100 grams of the phosphite in 100ml of HCl acid  and VERY SLOWLY heat it, you dont want to ever see it boil or bubble. Heat it as high as you can without boiling. After 1/4 of the solution has evaporated it should be ready for use.

Someone also told me this also works for Sodium and Potassium Phosphite but the ratios are slightly different ( 90 grams, 100 ml )

halfkast, does this make sense to you? I'm going to attempt to read your post again and fully understand it someday but the picture is slowly getting less fuzzy...

Three months ago I attempted to do this and then decided not to try it after combining the 30%HCL and the O-Ethyl Phosphonate powder in a mason jar. It now sits in the dark in the mason jar wrapped in a towel in a tuperware container. At this point, expert advice would be much appreciated as to the viability of this endeavor at this point in time and/or whether this should instead be disposed of properly post haste.

halfkast

  • Guest
The Na will work just as well, but you'll have
« Reply #11 on: September 10, 2003, 08:22:00 AM »
The Na will work just as well, but you'll have an even higher theoretical yield.
But the Na phosphonate brobably won't bee as common, for plants at least, beecause plants don't use it much, so the manufacturers choose the K.


I can't comment on C6H18AlO9P3 (aluminium tris stuff) but I would keep the powder tucked away for the future, in hard times only.
Work with K salts, they're common in aqueous solutions and probably in solid form too, which is excellent...

Okay...what you want to do is mix 1 mole eqivilant of the aqueous solution of phosphites (di actually), with 2 moles of HCl to get a return of 1 mole of H3PO3.

Well, I prefer to call it a solution of phosphites, or if I want to bee specific I would detail that it is a solution of mono-potassium phosphonate and di-potassium phosphonate salts.
I wouldn't say that I have a solution of di-potassium phosphite and mono-potassium phosphite.

You have two choices, actually 3.
1. you can simply multiply divide the amounts that I've used, in ml, or
2. You can calculate the molar ratios; ignoring volumes.

3. Your can give me the relevent numbers (HCl conc. and foliar conc.) and Ill give you the ratios in ml.

I was considering writing a java script so readers could enter they're concentrations of foliar solution and HCl, but a) I thought it was better to get it out there and b) I didn't know if it was suitable for various reasons.


halfkast

  • Guest
Highly interesting but..
« Reply #13 on: September 15, 2003, 02:15:00 PM »
Why is it here Rh?
Is this a secret post where the gremlins won't look is it?

Rhodium

  • Guest
Oops, off topic.
« Reply #14 on: September 15, 2003, 02:22:00 PM »
I didn't notice at first that it was off topic, as it was discussed above in the three posts listed below. I simply wanted to clarify the procedure when I saw it being discussed.

Post 457094

(hellman: "shit, what the fuk is this, repost if necessary", Stimulants)

Post 457113

(abolt: "Fester", Stimulants)

Post 457173

(raffike: "It might work but that manganese salt is ...", Stimulants)

halfkast

  • Guest
hmm Forgiven
« Reply #15 on: September 15, 2003, 02:36:00 PM »
*screenshot*

That's okay Rhody

awayman

  • Guest
This is great!!!!
« Reply #16 on: September 15, 2003, 05:15:00 PM »

abolt

  • Guest
My 2 cents
« Reply #17 on: September 16, 2003, 10:28:00 PM »
Here are some thoughts I have had about your "fungicide spray" write-up. This should be quicker, higher yielding, and scale up easier

If you have glassware and an aspirator I would add the 30% Hcl (why do you dilute it?), then setup a distillation rig on a water bath and distill off most or all of the water.

Then I would pour in say ~100 ml of MeOH into the solid mass, reflux for 30 mins, and then filter out the left over KCl.

Distill off the Meoh, on a water bath and dry leftover H3PO3.

Why MeOH?............It has less water and unlike Metho (denatured alcohol), it forms no azeotrope with water and can be permanently recycled.


halfkast

  • Guest
abolt thanks! Wetness of the alcohol doesn't...
« Reply #18 on: September 17, 2003, 12:38:00 AM »
awayman, since you put it that way, it's an honour! haha
are you Ozzy?
(PM us if ya want bee)

abolt thanks!

Wetness of the alcohol doesn't matter at all, neither do azeotopes. It might in yours though =)

Bad lab technique

The yield is quantitative for the procedure. I just don't like saying that.

I think DCM can bee used to extract KCl from aqueous solutions. I'm not sure about H3PO3. You?
Ill test it, but Ill have to create another sample and distill some DCM-time. I ONLY tested for the procedure and discarded.  :P


Diluting is probably unecessary, but it's easier to work with when it isn't fuming.

There's quite a few errors in there if you look over it, but it's my first write-up. It functions as stated.

Vacuum drying is highly desired. But the glassware setups looked complicated, but I've seen shorty mention that he vacuum-dried something recently.

Can you think of an easy ghetto vacuum dry?
Is this feasable: A fridge, a large drying tube or dessicator. I want it to bee with anybees household fridge in situ. Disconnect hose for process, reconnect==fridge as normal for anyones grandma. Basic enginuity. Can this bee accomplished?

Add this to the procedure:
During the final evaporation/H3PO3 crystalisation step, construct a means of suspending a piece of mesh loosely covered with large mesh activated carbon over the evaporation dish during this step.

a tightly framed piece of fine mesh for example.
Let there bee no sagging of the mesh in the solution.

abolt

  • Guest
another 2 cents
« Reply #19 on: September 17, 2003, 01:09:00 AM »
Wetness of the alcohol doesn't matter at all

Of course it does, if you can minimise water then you have less chance of KCl piggybacking the H3PO3 in the alcohol pull.

Solubility of KCl = 35 grams/100 ml water
Solubility of H3PO3 = 30 grams/100 ml water

neither do azeotopes

Good Bees recycle their solvents and alcohols. Utilising MeOH is the simplest way to do this, plus it has the added bonus of less water.

I think DCM can bee used to extract KCl from aqueous solutions. I'm not sure about H3PO3. You?
Ill test it, but Ill have to create another sample and distill some DCM-time. I ONLY tested for the procedure and discarded.


I don't think DCM will work. Why would it select the KCl and not the H3PO3 as well? Like attracts like(usually), KCl and H3PO3 are both polar.

Diluting is probably unecessary, but it's easier to work with when it isn't fuming.

There are hardly any fumes with 30% HCl. Diluting it just makes your workup more tedious.

There's quite a few errors in there if you look over it, but it's my first write-up.

It's a good writeup, especially for this forum. It wasn't rated excellent for nothing. ;)

Vacuum drying is highly desired. But the glassware setups looked complicated, but I've seen shorty mention that he vacuum-dried something recently.

If you could do that write up, then you could do a vacuum distill/dry with your eyes shut.

Can you think of an easy ghetto vacuum dry?
Add this to the procedure:
During the final evaporation/H3PO3 crystalisation step, construct a means of suspending a piece of mesh loosely covered with large mesh activated carbon over the evaporation dish during this step.

a framed piece of fine mesh for example.


If this step is for the drying of your H3PO3 crystals then I will give you an easier and more efficient technique.

Place your wet crystal mass, on a dish, in an air tight container (tupperware) and place a glass jar, half filled, with Sulfuric acid (bee careful) next to it then seal the container for a week or so. The sulfuric acid will absorb all the moisture.