oxalic acid strength

[chipper]

Finman, Have been struggling with the idiosyncrasies of the British Beekeepers since I started beekeeping 25 years ago.
Please do nt be offended....
We just like to do things....Differently.....!!
I use 90g oxalic acid 1 kilo Sugar 1 litre Water...
Personal preference... as the winters in South Devon tend to be short and mild and there is often brood all winter.....Not this one mind...!

 

[Finman]

We just like to do things....Differently.....!!
...!

Jep I have noticed. 15 years later than others.

Even James Bod was allways in a hurry. Bad guys must wake him up because he did not went to sleep in time. Too tired.

....
Tragedy: first you read the recipe and then you do something else. That is called dysleksy
.

 

[Finman]

.
Lets look the facts..........


BBKA Feb 2004
methods to control varroa.

– using Apiguard, oxalic acid and formic acid and
considering the precautions needed.
All of these treatments need to be used
with caution and certainly when the
honey has been removed from the hive.
There is a danger that they will contaminate
honey. Under the right conditions,
they are very effective and can kill over
90% of the mites present. Apiguard is
probably the safest and easiest to use.

British Beekeepers Association Advisory Leaflet Number B13
BBKA 2007
Obtaining the oxalic acid


Because the concentration is very critical
the BBKA advice is to obtain a PREPARED
SOLUTION of Oxalic Acid in sugar. There
are some available on the market from bee
suppliers such as:
Oxalic Acid from Endolapi SRL (Italy) which
is 6% of oxalic acid in a 30% sugar solution
Oxuvar from Andermatt. Which is a 3%
solution of oxalic acid supplied with sugar
to make up the desired concentration...
....The dosage required is 5 ml
(millilitres) per seam of bees. This can be achieved by counting the
number of seams where there are significant numbers of bees.
Multiply this figure by 5 and this will give the quantity in ml of oxalic
acid solution that should be applied to the colony.

 

[Finman]

.
What means the text: 6% ...3% and desired stuff.
Oxuvar from Andermatt. Comma in wrong place...

Mit OXUVAR® wird eine Oxalsäuredihydrat-Lösung 3.5 % zum Träufeln verfügbar gemacht, die sich speziell durch ihre einfache Applikation auszeichnet. Der Imker erhält die Qualität einer frisch hergestellten Lösung, ohne sich den Risiken des Abwägens oder dem direkten Umgang mit reinem Oxalsäure-Pulver auszusetzen.

Gogle translate With OXUVAR ® is oxalic acid solution 3.5% is made available to the trickling, which is characterized especially by its simple application. The beekeeper maintains the quality of a freshly prepared solution without the risk of weighing or the direct use of pure oxalic acid powder suspended.

 

[Finman]

.

What a mesh!.............>

 

[bees knees]

Happy new year everyone.
First time doing oxalic acid so thought i'd have a quick read here before going ahead - ended up more confused really. I have the same oxalic acid ready made up from Maisemore as Barry (and arl in picture on linked thread). It is the endolapi 6% OA, 30% sugar one which is pictured in the BBKA leaflet. It doesn't say on the bottle whether it is dihydrous or not. I decided to use it straight out of the bottle as this is what the Maisemore online instructions and the BBKA leaflet imply. Both our hives seem fine today - about 6 seams of bees each (one hive more lively that the other - bees started flying around) - so we'll see if any ill effects...
I think some people on the previous thread have mistaken the contents of this bottle for instructions. It reads 3%OA, 30%sugar, water up to 1L. I have a 500ml bottle but also comes in 1L bottles so i suspect the "water up to 1L" just means it contains up to 1L of water depending on which size bottle you have - a label produced to use on either bottle?? What does anone else think? It is a bit ambiguous i agree.

 

[fred]

I am still confused. If the BBKA say the concentration is critical why is the Endolapi 6% and the Oxuvar 3.5%. Should I dilute the Endolapi with sugar solution to achieve a 3.5% concentration of Oxalic Acid before applying at 5ml per seam?

 

[RoofTops]

If I remember rightly the higher strengths are used in southern Europe. About 3.5% is what is used up here in the frozen north.

 

[Sabrina]

When I treated mine, I used a friend's OA, also 6% from Maisemore. I diluted about 50/50 in a spring dilution sugar syrup and then treated as per instructions. Fingers crossed that'll do the trick! I'm new at all this, so there's a lot of finger crossing going on.

 

[MuswellMetro]

Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless but supports Bayer says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 or Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 or for N solution X 90.03/126.07

so do we call this 35% (w/syrup) or 4.3% (Wv) of dihydrate or 6.02%N of solution



so do we call this 35% (w/syrup) or 4.3% (Wv) of dihydrate or 6.02%N of solution



so do we call this 3.5% (w/syrup) or 4.3% (W/v) of dihydrate or 6.02%N of solution

who is right, could be that Th**nes 3.5% is the same as maisemore 6% but you would need to read the label more clearly

OK not a chemist but a physicists, but doesn't effect me as i use lactic (alegic to oxaclic and rhubarb)

Confused of Muswell Hill

 

[Finman]

who is right

)

You make those calculations from your own head. They are not needed at all.

It same like to make sugar syrup for feeding. 30 answers will raise during 24 hours and there is nothing odd in that doing.

I cannot understand what is so difficult in that trickling.


Trickling was studied 10 years to get good results and strong enough solution. After that one hive owners stepped forward and mixed the whole thing with their own ideas.

To me disease control is a serious issue. It is not social happening.

.

 

[MuswellMetro]

corrected pressed ther wrong button

]Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless but supports Bayer says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 or for n solution X 90.03/126.07)

who is right, could be that Th**nes 3.5% is the same as mai****re 6% but you would need to read the label more clearly

OK not a chemist but a physicists, but doesn't effect me as i use lactic (alegic to oxaclic and rhubarb)

Confused of Muswell Hill:rofl

 

[broandy]

corrected pressed ther wrong button

]Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless but supports Bayer says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 or for n solution X 90.03/126.07)

who is right, could be that Th**nes 3.5% is the same as mai****re 6% but you would need to read the label more clearly

OK not a chemist but a physicists, but doesn't effect me as i use lactic (alegic to oxaclic and rhubarb)

Confused of Muswell Hill:rofl

You not on your own lol

 

[MuswellMetro]

You not on your own lol

last post of this, i going for a G&T and about 42 degrees proof

the 35g in 1000 syrup appears to be


3.5% (w/syrup) or 4.3% (W/v) of dihydrate or 3.07%N of solution

 

[Finman]

.
It depends just on you what are you making. After calculations do not help.

If you make 3.5% solution do it. Weigh the stuff and mix it.

If bees are alive next day, it is a miracle! Halleluja, but not calculations after wards.

- is it normal that a dead bee is on snow
- No, it should be at least 10 bees. The others may be dead.

 

[gavin]

Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless but supports Bayer says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32 or Ok its a long time ago since idid this SO I MAY BE WRONG but as far as I can see

Standard dilution used in intial experiements was 7.5 grams or 8 grams per 100 grams of water =100grmas of sugar

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup.

Add 8g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 5mls (I'm guessing but not far out) .... so 8g in 167.65 ml is ... 4.77%!

That is of course 4.77% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.77% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.77% = 3.41%.

So do we call this call it 4.77% (w/v) of the dihydrate. Or 3.41%N solution

7.5gms was 4.5%(w/v) of dehydrate or 3.2%N solution


a site that shall be nameless says add 35gm to 1000ml of 1:1

so I that not 3.5% of water but syrup

3.5g in 100 of syrup

or 3.5g in 100/1.2296 of water = 3.5g in 81.32

{snipped a repeat**

who is right, could be that Th**nes 3.5% is the same as maisemore 6% but you would need to read the label more clearly

OK not a chemist but a physicists, but doesn't effect me as i use lactic (alegic to oxaclic and rhubarb)

Confused of Muswell Hill

You are a lot closer than Finman but if you are going to copy a post of mine elsewhere then change the numbers you ought to have a good reason for making the changes. I posted this on 30 Dec in the other place. As far as I can tell it is accurate.

--------------------------------------------------------
Hi John

50% (1:1) sugar syrup has a density of 1.2296 g/ml to water's 1.000 (at 20C)

So 100g sugar and 100 ml water yields 162.65 ml of syrup. Let's check: 162.65 x 1.2296 = 199.99g, close enough to 200g, the weight we started with.

Add 7.5g oxalic acid dihydrate to 162.65g syrup and that will add some volume .... let's say 4mls (I'm guessing but not far out) .... so 7.5g in 166.65 ml is ... 4.5%!

That is of course 4.5% oxalic acid dihydrate, the stuff you can buy as crystals. If you want to convert that to the equivalent of anhydrous oxalic acid (to take out the 'water of crystalisation') then you can multiply the 4.5% by the molecular weight of anhydrous oxalic acid and divide by the molecular weight of oxalic acid dihydrate ie (90.03/126.07)x 4.5% = 3.2%.

Just as valid to leave it as a % of the oxalic acid dihydrate, as the Charriere and Imdorf paper did. So I call it 4.5% (w/v) of the dihydrate.

So, to make 4.5%:

- add 7.5g to 100g sugar + 100 ml water, or
- add 4.5g to syrup and make up to 100ml once dissolved (to be picky)

... or any multiple thereof. And don't let any man from the far north tell you otherwise.

hope that was clear ... if not, ask a chemist!

Gavin

-----------------------------------------------------------

Thornes sell 4.5% (w/v) oxalic acid dihydrate aka 3.2% (w/v) oxalic acid.

cheers

Gavin

 

[Finman]

So, to make 4.5%:

- add 7.5g to 100g sugar + 100 ml water, or
- add 4.5g to syrup and make up to 100ml once dissolved (to be picky)

hope that was clear ... if not, ask a chemist!

Gavin

-----------------------------------------------------------

I am a chemist. What is idea to write wrong formulas? Have you taken your medicine today?


7.5g oxalic acid + 100g sugar + 100 ml water = 3,5%

And you need no density calculations

.

 

[Finman]

Introduction
Varroa (Varroa destructor) mites can be effectively controlled by use of OA dripping (Nanetti and
Stradi, 1997). However, reports from Germany, the Netherlands, Switzerland and Italy indicate a
concentration related bee tolerance problem. High concentrations (4.2%) is extremely effective, but
may influence spring development in colonies in the sprinjg after winter treatment. At the same time
lower concentrations (2.1%), using the same amount of liquid has no adverse effect on colony
development. It has not been clear, however, if it is the concentration of the solution applied that is
critical for high efficacy or if similar mite control may be achieved using the same total amount of
OA, but in a lower concentration. We have recorded the efficacy on mites and spring development in
honey bee colonies using two concentrations of OA but applying the same total amount of the active
ingredient in both groups.

http://www.culturaapicola.com.ar/apuntes/sanidad/08_san_oxalico_concentracion.pdf

 

[gavin]

I am a chemist. What is idea to write wrong formulas? Have you taken your medicine today?


7.5g oxalic acid + 100g sugar + 100 ml water = 3,5%

And you need no density calculations

.

The density value was not to help anyone with the calculations, but to try to put right some of the confusion you have been spreading on the topic. Syrup volume does not equal syrup weight, and the concentrations have always been expressed as weight:volume (w/v) percents.

Please, keep quiet if you don't understand something. You do have beekeeping knowledge that it is useful to pass on, but if you keep spouting nonsense on things you don't understand you are just going to make yourself look silly and unreliable.

7.5g oxalic acid dihydrate + 100g sucrose + 100 ml water does *not* equal 3.5%, but either 4.5% or 3.2% depending on your definition, as we have discussed at length.

There *are* people out there who deliberately choose 3.5%. That is 3.5% oxalic acid dihydrate (w/v) which could also be expressed as 2.5% oxalic acid (w/v) if you recalculate to take out the water in the crystals.

By miscalling the 7.5+100+100 recipe as 3.5% once again you are confusing people. Please, please, please don't do it any more!

Gavin

 

[MuswellMetro]

The density value was not to help anyone with the calculations, but to try to put right some of the confusion you have been spreading on the topic. Syrup volume does not equal syrup weight, and the concentrations have always been expressed as weight:volume (w/v) percents.

Please, keep quiet if you don't understand something. You do have beekeeping knowledge that it is useful to pass on, but if you keep spouting nonsense on things you don't understand you are just going to make yourself look silly and unreliable.

7.5g oxalic acid dihydrate + 100g sucrose + 100 ml water does *not* equal 3.5%, but either 4.5% or 3.2% depending on your definition, as we have discussed at length.

There *are* people out there who deliberately choose 3.5%. That is 3.5% oxalic acid dihydrate (w/v) which could also be expressed as 2.5% oxalic acid (w/v) if you recalculate to take out the water in the crystals.

By miscalling the 7.5+100+100 recipe as 3.5% once again you are confusing people. Please, please, please don't do it any more!

Gavin

gavin ,not intenended to take your glory, just used the first part to realte it to use of 8g in an old paper i had read on rothamsted work and the BBKA 35gms in 1litre, i acknowledge it is based on your post