Extracting H3PO3 from phosphite foliar solutions

[SHORTY]

Any refrigerator compressor will work as a vacuum but it wouldn't bee practical to make one which could be switched back and forth from fridge to vacuum.  Usually the vacuum lines are soldiered to the compressor and evaporator so they have to bee cut which will release all the refrigerant. So to go back to use in the ref. you would have to recharge the system after reconnecting the lines.

However, if you have an old refrigerator or a/c unit it is really easy to use as a vacuum.  Basically you just cut the 2 lines and remove any wiring which goes to the cabinet for lights or whatever and then put a an on/off switch on it.  You should also put some type of drying device in line with the intake cause if you don't it won't last very long.  I found that out the hardway when mine locked up. The whole thing is welded together so i cut it open with a metal cutting disk just to see what it looked like inside.  the piston on mine had become rusted causing it to stick.  I was gonna clean it and weld it back together but havent had time to yet.

[Scottydog]

"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."

*******

Swim will try this!

He had a jar of LG 97% H3PO3 that after having opened the jar only twice resulted in rxn failure. He was wondering why the rxn failed when the I2 and E reacted perfectly the following day with RP.

He assumed that the acid had oxidized to H3PO4.

He was sadly mistaken.

This salt is extremely hygroscopic and absorbs water from the air yesterday.

The water that is absorbed wreaks havoc when it comes to later additions prior to the rxn so water proportions must bee scaled down.

The jar is 7 mos old and figured it may now bee useless.

He tried only adding "half" the amount of water to the I2/ pseudo FB and H3PO3 as recommended in Rhodiums writeup and it fired off like a charm. Yep, even 7 mos later!

I believe Johndee addressed theoretical shelflife of the H3PO3 somewhere in the past (concerning oxidation)

I assume adding twice the amount of H3PO3 would also work?

Swim is beginning to think that a majority of failures can bee attributed to adding too much water!

Hope this helps others...

Great writeup halfkast. Sounds easy and straight forward.

I'm sure local nurseries would have steady access to this foliar fungicide.

[halfkast]

Your right. See, the procedure is really a failsafe softly softly approach, which costs mainly time, but it is fail-safe.
But I agree, all the diluting isn't really necessary and leaving it out would bee optimal.

So in step 1: Don't dilute your 100ml of 400g/L foliar solution.

As for the Hcl  it should bee diluted to a concentration where the individual bee is comfortable working with, with cold water. 50-100ml is fine.

Yeah but the alcohol moves the equilibrium drammatically in the H3PO3's favour
Also I doubt whether those numbers hold true in most cases.
i.e. If you have 100ml of pure water, add 35g of Kcl and 30g of H3PO3. The Kcl will precipitate I think.

Precisely, DCM is non-polar and can extract Kcl from aqueous solutions, see? It's just a matter of whether it also extracts H3PO3, it can bee tested because I'm interested but you'll have to wait!

In any case these types of solutions, extra steps and changes are for a different write-up. That's why it's called the simple extraction of H3PO3 from foliar solutions.

abolt: H3PO3's incompatible with strong oxidizers, so sulfuric is a horrid choice

The charcoal step is for removing oxygen from the atmosphere, not for drying.    Although that could bee a problem, the carbon getting saturated with OH/H2O vapour.

I thought about the charcoal, I think it would bee an excellent addition to remove O2. But not only for covering the evaporation dish, also add a tray of it on a lower level in the lab oven while pre-heating...as the air in a fan-forced oven is probably mostly circulated for efficiency.
Maybee even better(!) would bee an oven safe carbon filter hanging by some means (wire) at the back of the oven in front of the fan. Or ALL of these additions.

Covering the evaporation tray probably has the most questions hanging over it, doesn't it?
I think if you put a tray of AC on the bottom shelf, and a home-made (any ideas?) carbon filter hung in front of the fan by a wire to each of the side-rails, then placing one over the evaporation dish can bee omitted.



These are the types of changes that can bee made while maintaining simplicity:
1.Changes to dilutions/concentrations of Hcl and the foliar solution.
2.Changes to the rate at which the Hcl is added. i.e you can add it in one addition if you want to
3.Pre-heating the evaporation dish.
4.Any other little shit that you are prepared to change in exchange for no garantees by me that it will work, because I havent tested it.
5.Changes to the heat of both the OH or the temperature of the Kcl/H3PO3 before pulling.
6.Evaporating more water off before the H3PO3 pulls (and OH addition to precipitate out Kcl)
7.Activated carbon relating to the oven already discussed.


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.

Very true, good idea. But many bees would rather bee caught with methylated spirits.

Shorty that's just the sort of hands on know-how we needed thanks! Okay so fridges aren't really feasable.
So whats the most basic setup and conditions for this type of vacuum dry do you think?

Hey abolt next time you use that drying technique, add phosphorous pentoxide to the sulfuric. I think it might work even better.  

Scottydog, thank you  
don't test the sulfuric acid thing! Itll fuck it up hardcore.

Hey thats interesting scotty! So you think it's mainly water causing the problems?
How long and how big were those cooks man?
So you got no visual reaction or no conversion going by bioessay?

For drying your stuff...Pre-heat your oven and evap tray, put your soggy shit on there...heat it 70-90 for 10-15min take it out of the oven cover it with  plastic-wrap with absorbant paper taped to the inner side to absorb moisture and steam. place in the freezer...itll bee dry.

Oh yeah this is what I found.
If you don't use the absorbant paper with a drying agent taped to the plastic-wrap, you'll still get the nice wax, but it'll have some crystaline water upon freezing scattered over its surface.

If you do use the paper/drying agent patch, itll have a smooth surface upon freezing, no crystaline water from frozen steam.

Keep it in a dry place, avoid humidity. freezer is perfect.

Johndee was way too high, too.

[SFOtter]

I was just ordered over to this post by HalfKast to help me overcome the horrors of MBRP.

I can't offer much in the way of chemisty, but there's a product available at any good snotty wine merchant that might help prevent oxidation.  They sell small cans of inert gasses (I'm guessing it's nitrogen, but haven't for ingredient's yet).  Says it will prevent wine from oxidizing for up to a year with zero change in flavor.

BTW, thanks HalfKast.  I'm going to finish my first dream as planned out of shear bloodymindedness and then try your way.  That way I'll appreciate it even more.

[awayman]

SWIM recently found a device that is used for pressurizing fuel burning laterns. It works with a ordinary co2 cartriage. Instead of using the little pump device that is standard on the latern, you replace it with this thing. Rigging up an adapter for your storage container is easily done by a visit to the hw store, screw it on, insert co2 cartriage, and it's pressurized. Of course larger containers might not work with this device but for a gallon and down it does fine. Maintaining a good seal is crucial so use teflon tape on all connections.

[abolt]

abolt: H3PO3's incompatible with strong oxidizers, so sulfuric is a horrid choice

Hey abolt next time you use that drying technique, add phosphorous pentoxide to the sulfuric. I think it might work even better.


YOU DON'T MIX THEM TOGETHER!

hk, you asked the following question:

Can you think of an easy ghetto vacuum dry?

and I replied:

"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."

you could place the small glass jar of H2SO4 in another small plastic container, then place it in the tupperware container, as a safety device for spillage.

Precisely, DCM is non-polar and can extract Kcl from aqueous solutions, see? It's just a matter of whether it also extracts H3PO3, it can bee tested because I'm interested but you'll have to wait!

It won't work, that KCl is gonna like water/alcohol a hell of a lot more than it likes DCM...........but try it anyway.

[halfkast]

abolt there will bee fumes from the sulfuric.
Besides, I'm not even sure it will work to dehydrate the H3PO3. It will halt the hydration of it.

The bottomline is, it's not a good way of drying it. If it was, I'd like the idea; but it ain't.

Let me just check the DCM extracting from saline, I could bee wrong I seemed to have not saved what I was reading. You could bee right.



FOtter: If it is an inert, it's an excellent otc way for inert atmospheres! In the HI reductions too! Thanks  

>>I'm going to finish my first dream as planned out of shear bloodymindedness and then try your way.  That way I'll appreciate it even more.

Unwise, by the time you finish plan A, plan B could no longer bee an option.

[bigdumbnut]

Thanks for this very usefull and detailed info. I've UTFSE with no success though in one last detail. Your proceedure is for 400g/l concentration. SWIB has some foliar fertilizer  0-22-18 derived from phosphorus acid and potassium hydroxide. 100ml weights 127.5 g on a triple beam.Is this the same concentration? If not can you direct me in the right direction? Many thanks

[halfkast]

I can't work out very much with those numbers, sorry mate. Argox or someone else might bee able to. I don't even know what phosphite densities are, they aren't in the merck.

I find it hard to believe that they didn't put on the label a g/L make-up of the solution. They say nothing at all on the label?

crystalise 100ml of it and weigh it.

Of course you could use the amounts I prescribe, I doubt it is higher than 400g/L. The excess HCl won't do any damage at all.  

heh crystalise and weigh it though because I want to know what youv'e got too, plus its more fun, isnt it.  

[bigdumbnut]

100 ml of the foliar solution (forget the name but it was something like Fido-fox)was subjected to the concentration of HCl you used for 400g/l concentration. No additional water was added though.It was heated til slightly cloudy or KCl precipitating, cooled, refrigerated, and then subjected to Freezer stored Denatured OH til no more precipitation. This was repeated all day until no more salt reared it's ugly little head and then popped in the oven at under 200f with the door cracked open and a fan blowing in.The last part was the hardest for this old knuckle head. When is it time to throw it in the freezer with the "sticks everywhere you don't want it to wrap"? 
Well, I came up with 24 grams of h3po3 that surely has some water in it. Also I've saved all the salt in case I need some entertainment some night, I'll grind and wash for a little more.
  Don't know if it'll work but SWIBDN might try using it with less water than suggested to sidestep the overwatered thing. He thinks he can always add as things go on

[halfkast]

haha
OK thats wonderful, it wasn't a total failure.  

24gm is solid for a first try mate, you must have tried really hard, slick job!  

I've made the same mistake on the final evaporation, heh I was expecting to see a solid in the oven (duh me)

OKAY, when it's ready it's slightly viscuous. Not very viscuous but more visuous than alcohol or water.

I think the easiest way to judge its readyness for freezing is by taking a mental note of how it is when there is clearly and obviously some more evaporating to do.

Probably ideally it's best to remove your tray and cover it at the first moment of viscosity man!

But, although it might seem ideal at first thought to have a totally anhydrous wax. For weighting purposes.
With the flawed drying process, that is with some presence of O2 causing oxidisation.

The time that you stopped it could bee right on the mark-I'd take it.

Especially if swibdd one of these eye-balling type cooks, if your confident you can make a concentration of solution that will bee effective then do it.

[halfkast]

OK, the idea I did have in mind was to distill the water out rather than do it in the open air, but I'm not even certain the Net result will bee the solution and H3PO3 beeing exposed to less oxygen. Plus the time will bee much longer, especially if it isn't transferred to progressively smaller boiling flaskes.

How about a thin layer of cooking oil on top of the aqueous/oh during boiling?

This has been tested- this relates to a certain way to remove KCl in it's entirety...Use HCl to salt it out, perform this in whichever way you like. KCl is practically insoluble in concentrated HCl.
The HCl removes itself.

Maybee even gas the foliar solution from the outset, but that hasn't been tested. Would the concentrated HCl ever salt out the H3PO3?
I've got a strong feeling it wouldn't, but that it might cause more fuming of the HCl, and that if it is filtered in this state it would bee of excellent purity as far as KCl goes. hmm?


Separation and purification of anhydrous mixture of H3PO3 and H3PO4. We simply need to exploit the 30C difference in melting points, H3PO4 m.p at 42.35C, although if it has formed the hemihydrate due to prolonged cooling this portion's m.p will bee 29.32C..this is convenient as both temperatures are well below H3PO3's at 73C.

What needs to bee done, to do this easily, is to have a colomn of the mixture at one side of a sealed square evaporation dish.
To remove this from the freezer and to set this dish up on an angle (?, slight?) on top of a heating pad (?, iron? VCR maybe?) , and to heat it slowly, and evenly...so the H3PO4/phosphIC 'cid makes it's way down the slope.

[biotechdude]

quote<<
Separation and purification of anhydrous mixture of H3PO3 and H3PO4. We simply need to exploit the 30C difference in melting points, H3PO4 m.p at 42.35C, although if it has formed the hemihydrate due to prolonged cooling this portion's m.p will bee 29.32C..this is convenient as both temperatures are well below H3PO3's at 73C.
>>quote

Just a brain storm re removing SOME of the H3PO4 / phosphorIC'd unwanteds.  Could you turn on the hot and cold taps to get it to the right position that flows out water off as close to 45`C. 

Then get the raw frozen foliar extract in a little jar and raise it up on a little stand (for even heat transfer) inside a small saucepan.  Than let the 45`C tap water flow into and overflow out of the saucepan; slowly heating the contents of the (O2 and H20 sealed) extract jar to as close to 45`C as possible. 

Then could you just decant or suck out the melted liquid (of H3PO4 and phosphorICs); leaving the still solidified H3PO3 inside (as it wont melt until 73`C).  I know this wont remove all of the unwanteds, and you may loose a little H3PO3 (possibly that tightly bound to H20); but the nett effect will bee far purer H3PO3 solids that can be refrozen and used.

Quick, easy....and pointless?? Please advise

[halfkast]

the conciencious and astute biotechdude.

Of course, anything you do to apply heat and use gravity to separate will cause some sort of separation one would have to assume.

you know I love that idea of heating. How about we take your saucepanx and place a smaller saucepan upsidedown inside and use that as the heating surface?

Or maybee wrap it in foil? and submerge it in a saucepan containing water of a measured temperature?


this problem isnt going to last long i dont think.  

[halfkast]

It's now the authors preference that the free-water is evaporated at room temperature using a regular fan and or an air-conditioner.

It's unknown what rate the H3PO3 oxidates but it will happen much slower at room temperature. It was tested because of reading this that day when you and I were discussing ratios of HI:E when no recylcing agent was used. This is you I'm referring to biotechdude

'As a rule of thumb, reaction rate doubles when T is raised by 10-15°C. Therefore a temperature difference of 100°C means an acceleration of the reaction rate by a factor of 27 - 210, or 130 - 1000 times faster.' Os


Using a fan and and air conditioner or air dehydration unit doesn't take much longer at all.

The end product is pure white, which was surprising. Beecause I put the yellow down to Cl.

The hygroscopic water still hasnt been dealt with but I'm pretty sure the fan + A/C will do it, but the process had to bee shut down and refrigerated for time managment reasons.


I feel crap but I thought it was only right to post the findings so you could work with them.

[SHORTY]

It's now the authors preference that the free-water is evaporated at room temperature using a regular fan and or an air-conditioner.

I havent used this procedure so i may bee way off base here but have you tried using silica gel to remove the water in a sealed container.  It would take longer but in a sealed container the oxidation would bee slowed significantly.

I too have wondered how much oxidation takes place when i make hypo from sodium hypophosphite because i have to evap off alot of water in order to remove the salts from the solution.  I used to bee really worried about it and for a while i evapped under vaccuum until i broke the pump.  Afterwards i just heated it so that it steamed and let it evap slowly without boiling so that only the surface of the solution would bee exposed to air. 

I then figured that if i was oxidizing too much to phosphoric acid then it would not react when iodine was added.  However, I guess this would bee different for phosphorous acid since it has to bee heated before it will react.

[bigdumbnut]

Swib tried something based on several ideas read here. He extracted from 200ml Foliar with no added water. He ended up with 69.2 G which he sucted up in a 100ml syringe. This sat in the freezer for a couple of days of cogitation. He then taped a small water bomb balloon over the discharge end and a large balloon over the plunger to the body of the syringe. The syringe could now be pushed and pulled while sealed from the environment. He then ran hot water into a 16 oz measuring cup for a while, then read 138F on the Tmometer. He put the syringe business end down into the cup with the water running lightly for 15 min. Temp remained constant. The innards of the syringe got semi-liquid. He pulled back the plunger, tapped on the side a little , then pushed in fairly hard. This syringe had no needle but a small opening thru which, now, came some liquid in to the little balloon. This was repeated until no liquid was visible. Then back in the water a couple of min and repeated as above. In the end he had 33.8 G of slightly off white dry flakey/granular acid in the syringe and 35.4 G of smegma in the little balloon. I'm not sure how he'll prove it's purity yet, but I'll repost as soon as he does. Maybe how much I2 a given amount will turn into the correct G/ml acid?

[halfkast]

hehe what a liar bigdumbnut, thats pretty funny, it was crystalline was it?

do ya promise? or did you just add that on for fun?

anyway that part is unimportant.

Excellent experiment. Well done man.

Was it a pretty dry mixture u reckon?

for your next experiment, the balloon covering the plunger isn't required, but it was a great idea. Bee confident that not includeding it will have no detrimental effect as far as water or O2.

I was going to comment on density, hygroscopies of the both and how they would behave in the syringe, but it's not important.


Keep the nozzle on the syringe or whatever the correct name is facing towards the floor.

So was the stuff you expelled from the syringe more yellow or was it just thinner do you think?

[bigdumbnut]

Like compacted table salt actually . It appears quite dry but is still in the syringe figuring it will keep better there than elsewhere.
The yellowish color left with the liquid expelled and the next day had a greenish tint and had become solid (the expelled liquid that is). The ballon at the discharge contained the splatter that would exist otherwise but when the plunger was pulled back first the little ballon would suck flat and then some leakage would occur at the plunger. Without the big balloon there would have at least been moisture there to suck in. At least I didn't have to wipe water out first.

[dalewilj]

Swims dream did not work. Swim purchased Foliar Fert. from Ogasims Labs 0-22-18 : ; from lable. Total N 0%, Aval. Phosphorous Acid (P2O5) 22%, Soluable Potash(K2O) 18%
Derived from Phosphours Acid and Potassium Hydroxide. Name of product is Phy**-**s Foliar Fertilizer. Swim read others dream on how to extract. Follow step by step.Only different was use of iso alc. instead of Meth. Alc. Did not get get any precipitation of KCL xtals. On first step with HCl and foliar. Swim evaporated first step and put in freezer. 0 degrees over night. Did notice two seperater layers bottom more viscous than HCLmax solution.Bottom layer had higher vapor pressure than top layer. Left in fridge over night. In morning dreamt that xtals had precipitated out of solution. Both solutions had not froze. Did iso mix of both solutions no KCl preciptation. Warmed up solutions xtal went back into solution. Now dream is in fridge. Any ideas of what went wrong. Wrong foliar or wrong alc.