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Rhubarb and Oxalic Acid

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Google : ScientificBeekeepin.com... interesting article (peer reviewed)

Oxalic Acid is found in Rhubarb leaves.... now when I was working in the Uni labs it would have not been any great problem to extract and purify.

But looking on FleaBuy for the magic crystals found one site offering smaller quantities with a chemical analysis

:(:(:(Shock horror,.... contains 0.001% lead!!:ack2::ack2::ack2:

SciB reccomends a 3.5%wv solution of OA
35g oxalic acid in 1 litre of 50/50 sugar/water (white granulated)

3 to 5ml per seam in mid winter.... ONCE ONLY

Since the wood cleaning OA has nasty impurities... where can the beek. buy analar grade ... or at least the pure stuff

:svengo: Back to the Rubarb leaves??????
 

oliver90owner 

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I daresay that is the maximum likely? Or is it a typical analysis?

That amount represents just 0.35 of a milligram in each litre - enough for 20 hives!

So each colony might get a maximum of 17.5 micro grams.

Shared reasonably equally between 10,000 bees, that equates to 1.75 nano grams ber bee.

All, except the queen will be dead by May, not due to lead poisoning, I would think.

The AnaLar grade will likely be the same material but with a certified analysis, not just max levels.

Regards, RAB
 

annem 

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I bought some from Boots the chemist several years ago 500g Oxalic acid Technical grade. They ordered it in for me!
 

mhill20 

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Annem, was your oxalic acid in crystal form, if so did you mix it yourself and apply!!
 
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I daresay that is the maximum likely? Or is it a typical analysis?

That amount represents just 0.35 of a milligram in each litre - enough for 20 hives!

So each colony might get a maximum of 17.5 micro grams.

Shared reasonably equally between 10,000 bees, that equates to 1.75 nano grams ber bee.

All, except the queen will be dead by May, not due to lead poisoning, I would think.

The AnaLar grade will likely be the same material but with a certified analysis, not just max levels.

Regards, RAB
On U~tube the Newton Abbot beeks say 4.5% Oxalic acid in a 30% sucrose solution... so the BeeScience website[ in the US ofA ] is way out !
Do they mean 3.5g / litre... [3.5%w/v] ?????
:banghead:How did they ever get men on the moon???????????
 

oliver90owner 

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Oxalic acid crystals can be either pure oxalic acid (anhydrous), or more normally the di-hydrate. Relative molecular masses are about 90 and 126 respectively.

RAB
 
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Oxalic acid crystals can be either pure oxalic acid (anhydrous), or more normally the di-hydrate. Relative molecular masses are about 90 and 126 respectively.

RAB
That is just why Chemists [as opposed to Pharmacists] use molar solutions

A Mole in chemistry terms is the gram equivalent weight.... molecular weight of oxalic acid [ethanedioic acid] is 90 ( thats just a number!)
chemical formula is C2O4H2 for the anhydrous form, add . 2H20 for the dihydrate form we can buy.
add up all the molecular weights
2 x Carbon 12 = 24
4 x Oxygen 16 = 64
2 x Hydrogen 1 = 2

Molecular weight = 90 ( remember 90 is just a number)

If we weigh out 90 g of Oxalic acid and make put it in a graduated flask and make that up to 1 liter with water we have a 1 molar solution.

Now Chemists work in moles/molar solutions to make it easy for themselves and generally have pure chemicals and accurate balances to work with.
And to me always seemes to be hiding behind a complicated conurburation of apparatus mumbling in alchemistic tongues about double bonds etc etc

Just to fudge all this we would be using the dihydrate which dissasociates when dissolved in an aqueous solution and the amounts have to balanced out

However we are beekeepers and life without maths and chemistry is difficult enough!

Wally Shaw's Oxalic Acid treatment suggests a mix (accurately weighed) of

1 kg sugar + 1 litre of water = 75g of oxalic acid dihydrate

I calculated that this gives a 4.5% w.w solution of OA in a 50% sucrose (sugar) solution, which is the same as the Newton Abbot u~tube vid states

with 5ml dribbled between each frame of clustered bees in either late December or early January.
Suggestion is that OMF floor screen should be removed to cool the bees into cessation of brood rearing before application
ONLY APPLY ONCE PER YEAR

From the scientific papers I have read there seems to be little indication that OA if applied correctly is going to kill all your bees...............

but is a method that successfully reduces the population of varroa mite.

I would really like some sensible feedback on this subject.... perhaps it should become a "sticky" if headed correctly

RaB.... with the deepest of respect, would not all the workers present in a hive in December be well past their respective sell by dates by the end of May?
 

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So are you saying you need 126g of dihydrate to be equivalent (that takes me back to the early 1960s before 'equivalent weights' were replaced with 'molarity') to 90g of anhydrous acid. Relative atomic and molecular (molar) masses are used now (RAMs and RMMs).

Things used to be relative to hydrogen which was given the arbitrary atomic weight of 'one'. Then they changed and compared everything to Oxygen-16, then everybody decided to standardise on comparison with Carbon-12.

We no longer refer to 'weights' as weight is a force; so mass is used. The weight of any mass depends on it's location - a one kilogram mass on the Earth will weigh 10 Newtons approx (on the surface) but only about 1.6 Newtons on the Moon. Simple really.

So these days all mass numbers are sorted out relative to the carbon isotope with 12 nucleons (there are others), which has been assigned the abitrary mass number of 12 exactly, not an amount of substance.

I mole if a sustance will contain about 6 x 10 (to the power of 23) atoms or molecules.

That is a very large number. For the carbon standard, it is exaclty 12g and is called the Molar quantity or commonly the 'Mole'.

Chemistry is simple really!

Regards, RAB
 

oliver90owner 

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icanhopit,

with the deepest of respect, would not all the workers present in a hive in December be well past their respective sell by dates by the end of May?

Most books use the terms 6 weeks in summer and 6 months in winter, so with deepest respect from this end I would say - it depends on where you are located, the length of time the bees are clustered (and not brooding) and other factors.

Lets consider the last bees emerging which could be in December. No brood to service so they would not physiologically age and pass to the forager stage until maybe a couple or three weeks after brooding restarts with gusto in the Spring. That nicely gets the first brood cycle out of the way, with new house bees starting to take over brood rearing duties. What this means practically is that nearly all the winter bees will be dead by about six to eight weeks after the brooding and foraging recommences in Spring. In the UK, this is probably by early May, in other regions timings will be different.

We do have an international audience on the forum, so we should not be too parochial with our views.

Regards, RAB
 
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RAB me ol' M8 I was trying to keep it simple!
Never really did get a handle on all those Normal and Molar solutions... but when I was a lad 240pence = £1 and it was a paper one at that, Spuds were sold by the stone and OS maps were 2 1/2 inches to the mile.

and bees were kept in " proper " beehives !

Would just love to know if you will be treating your bees to a dribble of OA this winter and what recipe you use, or would use if you did?

Had force 9 winds and 2 inches of rain here last night.. so must go and pick up the wallnuts before the squirrells get em!!!
Cheers
 

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