Elemental Phosphorus
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Issues with starch-iodide test strips
I've been trying to use starch-iodide test strips to test concentrations of acetone peroxide in solutions intended to decompose it. The starch-iodide
strips clearly work, since touching them to the pure peroxide they turn dark immediately. After they go in the ammonia solution, even with peroxide
touching them, they don't react. I was wondering if ammonia in some way screws up the action of the starch-iodide strips. Thanks in advance for the
answers.
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wg48temp9
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Iodine reacts with a solution of ammonia in water to form nitrogen triiodide. Perhaps that reaction interferes with your test paper reaction.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Pumukli
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I think the formation of NI3 is a slow reaction while I2 and starch reacts quickly. So I'm surprised by your result but can't explain it. 
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Ubya
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the oxidation of iodide by peroxide works in acidic solution, maybe the ammonia makes the strips basic enough that peroxide doesn't oxidizes it
anymore
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Elemental Phosphorus
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I think Ubya must be right, I tried some strips in a concentrated sodium hydroxide solution and they wouldn’t react either.
Thanks for the replies.
Also, is there any other way to verify the decomposition of the peroxide? Does it shine under a UV light or some other form of illumination, or is
there a non-pH sensitive peroxide test? Maybe I’d be best off just visually verifying that no peroxide crystals are left.
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Pumukli
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Probably he is right. When I tried to use KI-starch a few weeks ago I used to detect hypochlorite. And hypochlorite works on KI even in basic
solution, hence my confusion.
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Elemental Phosphorus
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Speaking of all that, does anyone have access to this paper who can post a pdf?
https://onlinelibrary.wiley.com/doi/10.1111/j.1556-4029.2009...
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Ubya
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sci-hub.tw/10.1111/j.1556-4029.2009.01130.x
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