notoxicshit
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Alkali nitrite salt (home production, purification via esterification)
So the more developed parts of mainland europe do in parts have the problem that "toxic" chemicals are not allowed to be sold.
Thus, many very important stepping stones in organic chemistry are lacking. One of these cases is the inavailability of nitrite compounds, leaving an
organic chemist pretty much handicapped.
While it's possible to get packages of pure nitrite in GB for example as some kind of curing salt concentrate, this in only sold as a ready-for-use 1%
NaNO2 99% NaCl mix in mainland europe.
Now with buying it over the counter turning out impossible and not finding it in any products as an undisclosed additive or the like, we can resort to
making it from OTC-available materials.
The prime, not so OTCish prescursory material is of course an alkali nitrate salt. Preferable would be a really hardware-store-level-OTCish material
like ammonia, as nitrate is not OTC anymore as well.
I suppose it's possible to make all kinds of stuff from hydroxylamine over nitrate to nitrite electrochemically using the normal household ammonia
(from 10 to 30 percent weight, watery solution).
Unfortunately, because of being very promising, effiency-wise, that is not what I got into concerning details.
What I did is try some of the conventional chemical methods you all probably know:
- Pb metal powder (yuck!) ground into alkali nitrate salt and heated or burnt
- C charcoal powder ground into alkali nitrate salt and heated or burnt (tried!)
unusual and one of the lost gems of versuchschemie.de:
- heating calcium formiate with an alkali nitrate salt to 200-300° C (90% yield in crude gas evolution yield test) (tried!)
my favorite:
- heating an alkali metal nitrate, best is KNO3 to an exact ideal temperature that lies around 400°C to have it visibly give off oxygen bubbles in an
equilibrium reaction with taking it up again (tried!)
There are many more and some may even be worth mentioning but they all have a thing I don't like in common. They produce a mix of two not easily
separable solids, that has contents not easy to quantify.
What I want is a big ass jar of 98% nitrite salt to reach into and not worry about killing my reaction. Though one question: I've read about the
nitrate ion in (aqueous?) solution to be pretty inert. Could we just use any of those 60 to 80 percent yielding reactions to produce a nitrite/nitrate
salt mix to use in excess and not have it interfere in most reactions?
Purification ideas:
It's for sure possible to find a cation that will allow for a maximum of solubility difference between nitrite and nitrate salts. This will allow for
fractionating crystallization. The nitrite is far more soluble in water than nitrate.
I find that not really attractive for several reasons: the melting point is so high that it's impossible to check so we would be working blindly.
There is a theoretical alternative in my eyes, which I have only seen discussed once and dismissed prematurely on the lost board versuchschemie.de:
Conversion of the dry reaction mix to a volatile compound (afters it's rid off non-NO²/NO³ compounds; resulting from any of the above mentioned
reactions; containing only varying NO²/NO³ alkali salts).
Following is purification by distillation and reconversion to pure nitrite salt with a cation of my choice.
I think nitrite esters (with any lower alcohols) could do it: alkyl nitrites or poppers. Although I can't find any directions on their hydrolysis in
terms of write-ups, I find it mentioned positively:
"Alkyl nitrites are easily hydrolyzed in aqueous solutions to yield each alkyl alcohol and in- organic nitrite; the hydrolytic reaction is even more
rapid in blood "
( cited from PDF: http://eknygos.lsmuni.lt/springer/124/153-158.pdf )
"Compared to structurally equivalent carboxylate Esters, alkaline hydrolysis of alkyl nitrites is much slower and acid hydrolysis is much faster"
(cited from PDF: https://pubs.acs.org/doi/abs/10.1021/jo00168a002 )
So I'm just off for a few minutes, fetching the needed blood from next door!
Also, I see how alkaline hydrolysis would be preferable over acidic, because the latter is reversible. If alkaline turns out to slow or otherwise not
okay, an idea might be to remove the alcohol set free by hydrolysis (by distillation, other ideas welcome; doesn't some molecular sieve catch methanol
or even ethanol?)
I'm gonna leave it at that now and add more info later.
Please check my thoughts for making sense and help me determine the conditions and setup for a nitrite salt producing hydrolysis procecure.
Also I think it would be possible to produce pure nitrite salts by having nitrogen oxide(s) run into the right solution. Via HNO², maybe.
We might even skip the whole nitrite salt step and make hydrolyzable Alkyl nitrites from gassing alcohol with NO or mixes of NO and NO²?
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DJF90
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Passing NO2 into an aqueous solution of KI will give you KNO2 and I2. Separating these should be trivial (extraction with nonpolar solvent?). Added
bonus of iodine byproduct too.
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VSEPR_VOID
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its too bad iodine salts are so expensive
Within cells interlinked
Within cells interlinked
Within cells interlinked
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notoxicshit
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Iodine salts are not too expensive for me, especially when the product is more valuable.
It is a seemingly great suggestion, but a sciencemadness thread revealed that it gives KNO3 as well.
It was discussed here but the talk drifts towards iodine production at the end:
http://www.sciencemadness.org/talk/viewthread.php?tid=22182
I'd like some additional opinions.
Maybe this is possible to do under non-aqueous conditions or there are other means to avoid KNO3 formation...
I'm afraid the problem is KNO2 + NO2 <=> KNO2 + NO independant from water.
It would be best to have an insoluble nitrite salt form and drop out.
But if we manage to do the purification right, the impurities of the many procedures available wouldn't matter anymore.
I don't see why I couldn't just drop a certain amount of hydroxide into the upper layer of a salted out upper layer of a isopropyl nitrite synthesis.
Maybe rotate it off once, add measured amount of hydroxide and maybe use the alkaline hydrolysis catalyst ß-cyclodextrin and have:
Isopropyl-NO2 + NaOH = Isopropyl-OH + NaNO2
Seems like I could afterwards rotate off the volatiles and check how much acid I need for neutralization of the solid residue and calculate how much
has been hydrolysed this way. Then I do some gas producing nitrite reaction and see if the volume coming out points at the same ball park of nitrite
yield I calculated.
What do you think?
[Edited on 3-3-2018 by notoxicshit]
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AJKOER
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Anal Sci. 2004 Dec;20(12):1759-62.
"Mechanism of the NO2 conversion to NO2- in an alkaline solution"
Chen X1, Okitsu K, Takenaka N, Bandow H.
Abstract
The reaction of NO2 and NaOH aqueous solution at room temperature was studied for elucidating the behavior of gaseous NO2 in an alkaline solution.
Experimental runs related to NO2 absorption have been carried out in various pH solutions. The nitrite and nitrate ions formed in these absorption
solutions were quantitatively analyzed. In the case of pH 5-12, both of the nitrite and nitrate ions were formed simultaneously. On the other hand,
only the nitrite ion was formed when the pH of the absorption solution was higher than 13. In this paper, a new reaction mechanism was proposed to
explain the selective formation of nitrite ion in the 10 M alkaline solution."
Link: https://www.ncbi.nlm.nih.gov/pubmed/15636532
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notoxicshit
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Well fuck me sideways, this is amazing.
Not even and iodide involved
This is exactly what I meant to find. I had a strong feeling that a superior nitrite synthesis is possible through nitrogen oxide gases.
Thank your very much.
Now I just need to find the most comfy way to make NO2.
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Corrosive Joeseph
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'Concentrated nitric acid is dropped on copper in the bottom of a glass cylinder, a reddish-brown cloud of nitrogen dioxide gas is rapidly evolved'
4 HNO3(l) + Cu(s) ==> Cu(NO3)2(s and aq) + 2 NO2(g) + 2 H2O(l)
https://chemdemos.uoregon.edu/demos/Copper-and-Nitric-Acid
/CJ
[Edited on 4-3-2018 by Corrosive Joeseph]
Being well adjusted to a sick society is no measure of one's mental health
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ninhydric1
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If you don't have nitric acid but have a nitrate salt, you can use HCl and H2O2 instead:
2HCl(aq) + 2H2O2(aq) + 2KNO3 (s) <--> 2HNO3(aq) + 2KCl(aq) + 2H2O(l) + O2 (g)
This equilibrium is strongly shifted to the left, which is why Cu is added:
4 HNO3(l) + Cu(s) --> Cu(NO3)2(s and aq) + 2 NO2(g) + 2 H2O(l)
which gives you your NO2.
The philosophy of one century is the common sense of the next.
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LearnedAmateur
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I can see a few problems with the isopropyl nitrite route. What would be your source? If you were to use poppers, they are pretty expensive (30mL for
like £2-£5), so you would need to invest a lot of money for relatively little product, not to mention that they usually have other additives as well
which may interfere. Plus, alkyl nitrites are pretty much insoluble in water so it may take a long time and quite a bit of effort to get the reaction
to completion, especially since you can’t use simple reflux since it boils at just under 40C.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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notoxicshit
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It wouldnt be a problem to source some impure nitrate for fertilizing purposes or HNO3.
I would use just about any of the aforementioned methods, preferably fluor or sawdust to reduce a lot of the nitrate to the nitrite and then use this
mixed salt to make alkyl nitrites which I purify by distillation and hydrolyze back to pure nitrite salt.
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LearnedAmateur
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Sounds like a pretty smart method, I didn’t think of that, the only experience I’ve had with alkyl nitrites is where I’ve made tiny quantities
from isopropanol and sodium nitrite as I was playing around with their use as a solvent. The low solubility of the nitrite ester means pretty much
95%+ product just floats to the top of the aqueous layer with very little remaining in solution with minimal water and <5C temperature. I’ve
never needed to distill it, IMO it’s got a similar sort of danger level to diethyl ether so be very careful, it might be better to just purify it
further with sodium bi/carbonate after decanting, then you’re ready to go for hydrolysis if you can figure out how to do it efficiently. Maybe try
experimenting with alcohol-water systems to help draw the nitrite into solution, then it’s just a matter of monitoring pH.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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woelen
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If you are in the UK, then why bother making nitrite? You can simply buy it cheaply from eBay. I myself also purchased it from eBay (from the UK,
having it shipped to NL). Right now there is this one:
https://www.ebay.nl/itm/Sodium-Nitrite-NaNO2-99-Highest-Grad...
One full lb of NaNO2 for only GBP 11.
Nearly always there is at least one seller, offering NaNO2.
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notoxicshit
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I am german and I fear the Zoll. I dont want any attention. Of course its not exactly illegal to buy a toxic compound but sale is and Im afraid they
are just going to keep it and land me on some creepy list of people they plan on checking out and/or visiting.
I have bad experiences with the authorities. They treat you really bad no matter what or even if you did anything not okay.
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woelen
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Sodium nitrite is not that toxic. It cannot be compared with e.g. mercury, lead or arsenic compounds. Nitrite even is consumed in large quantities. It
is used for curing meat (IIRC a few percent of NaNO2 mixed with NaCl). Of course you should not consume pure NaNO2, but in small quantities you eat it
every time you eat some meat.
It also is sold in NL itself without issue. I do not believe it is illegal to sell NaNO2.
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LearnedAmateur
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To be fair, it probably wouldn’t be that bad to order it from within the EU, from a somewhat private seller (definitely not a chemical distributor
if you don’t want any red flags) such as one in the UK. Usually you don’t have to worry about anything if the chemical in question isn’t subject
to stringent regulations such as requiring a license to buy/import/possess etc. But by all means, if you’re worried about any visits then it would
be better to make it yourself, you’ve got a better idea on German laws and how they would approach the subject.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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Fantasma4500
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i had 250g of properly labeled NaNO2 confiscated, dont think its really illegal here however. they ruled it as an ingredient in explosives
manufacture, nitrates didnt seem very useful - the hell do i know anyways.
i suggest iron oxalate to be used as reducing agent, or well the nanoiron formed in situ, should react quite well with hot sodium nitrate
it will form a mixture of iron oxides and hydroxides, some CO2 and by that some sodium carbonate, on top of that you have sodium nitrate impurities to
deal with, i think way to remove the nitrate would be to add yet more iron oxalate, much like how you remove ethyl alcohol from ethyl acetate, more
acetic acid, reflux and distill. i suppose the conversion using nanoiron would be quite successful simply because nanoiron is so reactive, maybe a bit
too reactive, could it degrade it further than NaNO2?
as for removing carbonate ascorbic acid or citric acid shouldnt form HNO2
i would suggest converting the nitrite into potassium salt, or barium maybe, where the nitrate has much lower solubility
it seems difficult to seperate nitrite from nitrate using OTC solvents, ether may be doable but ether is precious.
getting a bit frustrated with this purification because im quite sure that i had this thing settled some months back, but i must have forgotten to
write it down?
converting the nitrite-nitrate-carbonate into barium would at least take care of the carbonate, which is technically insoluble in water. aha. i would
for this suggest using barium chloride, as sodium chloride has a very mundane solubility ""curve"", in other words, a concentrated hot solution would
only precipitate nitrates/nitrites upon cooling, the sodium chloride would remain almost entirely in solution
2NaNO2 + BaCl2 = 2NaCl + Ba(NO2)2
NaNO2 solubility in solvents: Methanol 4.5g/l, Ethanol 3g/l, slightly soluble in ether, very soluble in NH3
wiki claims NaNO3 soluble in ethanol, turns out 1 gram dissolves in 125 ml Alcohol, 52 ml boiling Alcohol, 3470 ml
absolute Alcohol.
maybe barium is the way to go, maybe barium nitrate from start, iron oxalate ontop of that, barium carbonate ppts immediatedly (and pleasently quickly
due to how heavy barium is), excess iron oxalate to be used? usually nitrite is made by melting sodium nitrate, but using more reactants such as
nanoiron in situ from thermal decomposition, this could all together be avoided
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Akhil jain
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You can ignite the mix of 0.3g charcoal and 5g KNO3
2KNO3 + C → 2KNO2 + CO2
If you used more charcoal than the told quantity it will reduce the potassium nitrite formed to potassium carbonate
Another method is to heat a mix of FeO and KNO3
KNO3 + 2FeO → Fe2O3 + KNO2
You can bubble N2O3 through NaOH soln to get NaNO2
N2O3 can be prepared by adding Cu to 5M HNO3
N2O3 + 2NaOH→ 2NaNO2 + H2O
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AJKOER
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An aqueous path, to be tested, based on pure metal iron pretreated with hydrogen (say from heating FeO in much H2 forming once called porous iron
followed by a reaction of the liberated iron and water, see https://www.nature.com/articles/ncomms14096 ), is reported to work, but only in an absolutely oxygen free environment. See a historical source and
my updated attempt at the chemistry (in two responses) at: http://www.sciencemadness.org/talk/viewthread.php?tid=77186&... .
[Edit] The author refers to the iron as active iron, however, research suggests that the active agent may be a hydrogen atom absorbed onto the iron
surface (see https://www.sciencedirect.com/science/article/pii/0001616083... and https://www.phase-trans.msm.cam.ac.uk/2016/preventing_hydrog... ).
---------------------------------------------------------------
A possible slow embodiment would be to first fill an expandable container with boiled water, ordinary iron powder and some sea salt creating a neutral
solution, where the container also has inserted a test tube of hydrogen gas and hydrogen pre-treated Fe with a plug composed of dry KNO3. Tightly seal
the system. Next, after a day, invert the container and shake introducing aqueous KNO3 in an oxygen free environment with pre-treated iron. Stop the
reaction before Fe(OH)2 'aging' occurs in an hour or more, see page 762 at http://www.jbc.org/content/64/3/753.full.pdf), with, I suspect, the creation of Fe3O4 (FeO.Fe2O3) via:
3 Fe(OH)2 → Fe3O4 + 2 H2O + H2 (g) (Schikorr reaction)
Logic: iron powder first slowly consumes all the available gaseous/dissolved oxygen with also possible hydrogen evolution in electrochemical
reactions.
Guide as to quantities to employ:
Fe + 1/2 O2 → FeO (guess the volume of possible oxygen)
Fe + H2O + NO3- → Fe(OH)2 + NO2- (see SM link above)
Note:
2 Fe2+ + 2 H2O → 2 Fe3+ + H2 + 2 OH− (see https://en.wikipedia.org/wiki/Schikorr_reaction )
is a possible source of hydrogen gas leading to a container expansion/pressure increase.
----------------------------------------
[Edit] Assuming instead that surface atomic hydrogen is the active agent, the reaction could proceed as:
H + NO3- = OH- + NO2
2 NO2 + H2O = 2 H+ + NO2- + NO3-
.......
[Edited on 28-3-2018 by AJKOER]
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AJKOER
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Just completed a possible aqueous path to nitrite from nitrate, without employing any acid, based on the following half-cell reactions:
THEORY
2 Al + 8 OH- --> 2 AlO2- + 4 H2O + 6 e- Eo= -2.34 V (see http://www.dtic.mil/dtic/tr/fulltext/u2/d019917.pdf )
3 [NO3- + H2O + 2 e- --> NO2- + 2 OH- ] Eo = 0.01 V (see this excellent source but it is preceded by an ad https://issuu.com/time-to-wake-up/docs/electrochemical_redox... )
----------------
Net Cell Reaction:
2 Al + 3 NO3- + 2 OH- --> 2 AlO2- + H2O + 3 NO2- +2.35 V
Also, some of my prior comments and research on an alkaline Aluminum metal path are available at https://www.sciencemadness.org/whisper/viewthread.php?tid=52... .
PROCEDURE
I mixed up in 240 cc of distilled water 10 grams of KNO3 (around 5 cc) and added 2.6 grams of NaOH (around 1.3 cc). Then I measured out a targeted
amount of 67.3 sq inches of Aluminum foil. I place the Aluminum foil in a gas flame to activate the surface prior to adding to the basic potassium
nitrate solution.
RESULTS
Observed no reaction at first, but when I returned in about 30 minutes, the solution was warm and all of Al foil dissolved leaving behind a black
suspension of silicon impurity. I smelled the content of the vessel and was greeted with the scent of ammonia, but not too strong. This, however, is a
verification of the reduction of nitrate to lower nitrogen compounds including nitrite (if I repeat, I will use an excess of KNO3 and stirring to
reduce local concentrations). The pH of the final solution was 12.05.
The product is to be employed in a photolysis experiment where the nitrite is superior over the nitrate and the black silicon suspension may have
added value in capturing light.
Others are welcomed to repeat and verify.
Picture attached.
[Edited on 4-8-2018 by AJKOER]
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AJKOER
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Upon review of U.S. Patent 6,296,754 (‘Method of reducing nitrous oxide gas and electrolytic cell’, at https://patents.google.com/patent/US6296754B1/en ), which employs platinum group metals like palladium black (absent gloss with increased surface
area), it occurred to me that I should have mentioned the likely role of surface chemistry with respect to the hydrogen atom radical. In particular,
my suggested heat pre-treatment of the aluminum foil not only results in the removal of any oil or acrylic coatings, but also disrupts the annealing
process on the aluminum foil surface, thereby likely promoting the adsorption of hydrogen atom radical. The latter is created, in my opinion, upon
examining the referenced half-cell reaction:
NO3- + H2O + 2 e- --> NO2- + 2 OH-
as follows:
H2O = H+ + OH-
H+ + e- = .H (Al surface)
.H + NO3- = OH- + .NO2
.NO2 + e- = NO2-
Net reaction giving as required:
NO3- + H2O + 2 e- --> NO2- + 2 OH-
Bottom line, don't forget to preheat the aluminum foil in a gas flame! More generally, a likely understanding of reaction pathways may lead to
possible procedural enhancements.
-------------------------------
A side note, my recommended excellent source citation on the anode half-cell reaction is:
Al + 4 OH- --> H2AlO3- + H2O + 3 e- Eo = -2.33
only seemingly differs from the referenced work:
Al + 4 OH- --> AlO2- + 2 H2O + 3 e- Eo= -2.34 V
by using one of the H2O to hydrate the AlO2- :
AlO2- + H2O = H2AlO3-
[Edited on 5-8-2018 by AJKOER]
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JJay
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IIRC the typical test for nitrite is with silver nitrate, which forms a pale precipitate with nitrite.
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AJKOER
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Quote: Originally posted by JJay  | IIRC the typical test for nitrite is with silver nitrate, which forms a pale precipitate with nitrite.
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which assumes one has no chloride impurities.
Interestingly for KNO3 and KNO2, there is a large solubility difference in water (over ten fold depending on temperature, see https://en.wikipedia.org/wiki/Solubility_table#P ) and also in alcohol.
[Edited on 5-8-2018 by AJKOER]
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