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For a while now I have been kicking around the idea of conducting an experiment to see how much oxalic acid is contained in honey from hives that I am treating. I was going to test two hives. Hive one was going to have a series of five to seven treatments a week apart. Hive 2 was going to receive one treatment. The reason for this is I have done a series of treatments when I have brood and I have treated with m a q s late summer and a one shot of OA in the winter. I have only contacted one Laboratory but was shocked at the price they would charge. I was quoted $2,000 for one sample. Subsequent samples would be cheaper but I didn't bother to ask how much. The lab explained to me the challenges in conducting this test. I have to admit I did not really understand most of it not being a scientist. I am going to call around to see if I can get a more reasonable price. I am posting this for informational purposes but I am curious if anyone knows why this is so expensive and complicated. The amount of oxalic acid in vegetables such as spinach and kale is readily available so it can't be that hard or expensive to test I would think. I am interested in hearing from any scientists about this. My motivation for doing this is mainly personal and curiosity and I was hopeful perhaps I could advance the knowledge of OA and it's residuals in honey. On the personal side I extracted a bunch of deep frames in the spring and got 80 lb of absolutely delicious honey that I would love to eat but it looks like I will give back to the bees this fall unless I can assure myself that it is safe to eat. I do not sell honey and would only use this for personal consumption if the test results came back low. Any scientists out there? J
 

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It would be interesting to know, but when treating hives, I always put a piece of cardboard below the supers until after the treatment......if I treat supered hives.

However, I have pulled honey from brood boxes of deadouts that I've used for my table, and I'm still alive. :scratch:
 

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Check at a local university if you can. When I was at Penn State running a GC/MS "off the books" would have been easy enough. An organic chemistry prof may even welcome the opportunity for students to do real world analysis.
 

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Discussion Starter #5
Tim, if I had the money I would test supers that have been blocked off too. Some feel that the bees will get the OA on/in the honey or cappings after they are unblocked. Probably do, but in any significant amount?
 

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There is an older study (but darn if I can put my hand on it at the moment) that basically stated that honey had basically the same amount of OA in it after treatment than prior to the treatment.
 

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The cost isn't unreasonable; even a not-for-profit entity (e.g. university) wouldn't be able to do it for a whole lot less. Gas chromatography-mass spectometry is most likely the method that would be used, and since you're looking to detect something that is in (hopefully) trace amounts, this method gets pricey. Extremely high purity gasses and solvents are needed, as is a high-purity analytical standard for oxalic acid (which is needed so that they can identify the OA in the sample and quantify it accurately).

As an example, OA at sufficiently high purity (analytical standard purity) for GC/MS is ~$700/gram! Unless the lab was testing for OA frequently, they would have to purchase this.

Similarly, partial purification of OA from the honey would likely have to be performed first, in order to get it into a suitable solvent. Again, unless the company has done OA from honey before, they'd have to generate and validate that method.

It gets cheaper for subsequent samples because some of those costs are 1-time expenses (validation of the extraction process), while analytical standards are used in small amounts and therefore a little goes a long way.
 

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that basically stated that honey had basically the same amount of OA in it after treatment than prior to the treatment.
yes, but the devil is in the details
when you look at the body of work as a whole, a single late fall/winter treatment dose not significantly increase the OA in the honey crop next fall
However...anything but that, such as repeated treatments or treating in the spring trends toward an increase in OA...
there is nothing to suggest that repeated brood on OA treatments will not impact that years honey crop
OA res 1.jpg OA conmantion2.jpg
RADEMACHER 2005- Oxalic acid for the control of varroosis in honey beecolonies – a review, https://www.apidologie.org/articles/apido/pdf/2006/01/M6010.pdf

The research says if you follow the label no supers, late fall and early spring treatment there is little risk.

The real question is if the added OA is a problem
The solution to pollution is dilution if you make 10 kg of honey and you treated once, lets say 1/8 of it ends up in the supper.. so 250mg you have boosted you honey by 25mg/Kg no big thing, you treat 2 times now your at the difference between choosing a lettice or spinach salad... but 5 treatments in a row........ 5 treatments in a row 2 or 3 times. At some point there is an impact
 

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I don't see this article posted,
lol looks like there was an atachment issue here it is
OA res 2.jpg

The results of 26–34 mg/kg control and 22.8–37.7 mg/kg test group are not surprising and well with in natural variability.
OA doesn't penetrate capping.. They treated hives in late fall when the winter feed was capped and come spring there was still no OA in the feed that was protected by the cappings and as we see in the chart from my last post the oa has broken down by the time fresh nector has come in, months later

this study does not suggest that summer treatments won't end up in summer honey when open nectar is present in large amounts, or the flow is on. It just suggests that when used as directed by the label there is no issue
 

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Since oxalic acid is found in fairly high concentrations in normal foods I am not concerned about the possibility that treating in the winter would cause a minuscule increase of it in the following summer's honey.
 

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I don't see this article posted, but it's an interesting one from Germany.
...
In that study they also say that:

Screenshot_2018-07-04-10-10-06.jpg


Has it been even shown experimentally that OA accumulates in honey after repeated OAVs? This is just another reasonable and safe assumption without any available experimental data.
 

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Bay bee
Has it been even shown experimentally that OA accumulates in honey after repeated OAVs? This is just another reasonable and safe assumption without any available experimental data.
Except for the test that were run in the now five studies to prove out the statement that you highlighted. You either have to do your own study, base your opinion on what people took the time to study or just stay away from it cause you don't trust or don't think they studied the right thing and you don't want to do it yourself.

It seems to me that several studies saying the same thing would give a person a fair sense that it does not accumulate in honey and comb and it is enough for me to feel confident but each has to decide for them selves. If you spent the money and did it yourself to your satisfaction, others would probably not be willing to rely what you did but you could satisfy your own mind on it. Myself, I know I am not willing to spend a penny on it and so I have to rely on others and what they did study or stay away completely.

Everybody could donate to randy oliver who is repeating study on this for government approval if you are willing to wait for his results.
Cheers
gww
 

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time and timeing matters
Repeated application (4 times) in autumn or winter (3% oxalic acid dihydrate, 50–80 mL depending on colony size) increased the oxalic acid content in honey after the treatment by 13 and 18 mg/kg, respectively (Floris et al., 1998; Nozal et al., 2000).

In spring (March), a single oxalic acid treatment (3%, 3–4 mL per comb side) caused a significant increase in the oxalic acid content in honey up to 62.8 mg/kg eight days after the treatment (Kruskal-Wallis-test, P < 0.05). By June, the levels in honey were back within control limits (Brødsgaard et al., 1999).
Repeated treatments with oxalic acid dihydrate solutions from 3.5 and 6% and 50–55 mL per hive slightly increased the oxalic acid content in honey after treatment by 22 mg/kg (Floris et al., 1998) and in spring honey by 0.3 mg and 7 mg/kg, respectively (Moosbeckhofer et al., 2003; Bogdanov et al., 2002)
Treatments in spring or summer with varying dosages led to somewhat higher oxalic acid contents in the honey after application (Liebig, 1999; Brødsgaard et al., 1999)
Single autumn treatments using oxalic acid dihydrate (3.1 to 6%, 5 mL/bee space) were conducted in several studies. Nanetti and Stradi (1997) reported that the content of oxalic acid in the remaining winter food was not increased.,
RADEMACHER 2005- Oxalic acid for the control of varroosis in honey beecolonies


It seems you can blast away all you want late fall and likly early spring and have little effect on your Aug harvest, do the same in july its a different story... as baybee's snip, states they are talking about spring honey, many months after the treatment, it takes time for the OA to break down and get out of the hive, and as the studys show the more OA you put in the hive, the higher level of OA the hive has. Yes its no like outher cems that are there for years and years. but nether does it vanish instantly'

Randys work is good, but the new slow release polymer system that does OA and FA at the same time is very promising, and is sposed to be very affordably... not wood bleach cheap, but some one needs to be making money to pay for tests/epa aproval etc

take it for what its worth... witch dosent seem like much around here
 

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diet is 70–80 mg and can reach up to 400–600 mg/day in a vegetarian diet (Gay et al.,1984). Poul (2003) estimated the mean dailydietary intake of oxalic acid to be 80 mg/day.An ADI (acceptable daily intake) of 0.89 mg/kgwas suggested; this corresponds to a safe dailyintake of 53.4 mg/day for a 60 kg human. TheUS Environment Protection Agency concludedthat 0.14 mg oxalic acid or oxalate/kg/day overa 24-hour-period represents the allowablehuman exposure from all sources (US EPA,1992).Assuming a daily intake of 20 g honey witha high content of 200 mg oxalic acid/kg honey,the additional consumption of oxalic acid willbe about 0.067 mg/kg b.w. for a 60 kg person(Wibbertman, 2003). The author concludedthat this would not cause a risk to human health.The theoretical oxalic acid intake in honeyfrom either treated or non-treated bee hives isnegligible when compared to the daily intakefrom other sources (Commit
From here
https://www.apidologie.org/articles/apido/pdf/2006/01/M6010.pdf

With this as a reference of what can be normal in honey.
Concentrations in honeyvary between 3.3–761.4 mg/kg (
Cheers
gww
 

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Baybee
Have you read all the studies that have been linked to? MSL I know you have read them and found several of them for me to read also.
Cheers
gww
 

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gww as I said in post 8
The real question is if the added OA is a problem
the OP has about 36 kg of honey to eat...at the suggested 20g a day dose of honey it would take him like 98.5 years to eat it
 

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msl
I knew you read it all and like I said, I would not have read half of it with out you.
Thanks
gww
 
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