Elemental Phosphorus
Hazard to Others
Posts: 184
Registered: 11-11-2016
Location: Is everything
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
wg48temp9
National Hazard
Posts: 761
Registered: 30-12-2018
Location: not so United Kingdom
Member Is Offline
|
|
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.
|
|
|
Pumukli
National Hazard
Posts: 686
Registered: 2-3-2014
Location: EU
Member Is Offline
Mood: No Mood
|
|
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. 
|
|
|
Ubya
International Hazard
Posts: 1231
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
|
|
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
---------------------------------------------------------------------
feel free to correct my grammar, or any mistakes i make
---------------------------------------------------------------------
|
|
|
Elemental Phosphorus
Hazard to Others
Posts: 184
Registered: 11-11-2016
Location: Is everything
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Pumukli
National Hazard
Posts: 686
Registered: 2-3-2014
Location: EU
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
Elemental Phosphorus
Hazard to Others
Posts: 184
Registered: 11-11-2016
Location: Is everything
Member Is Offline
Mood: No Mood
|
|
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...
|
|
|
Ubya
International Hazard
Posts: 1231
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
|
|
sci-hub.tw/10.1111/j.1556-4029.2009.01130.x
---------------------------------------------------------------------
feel free to correct my grammar, or any mistakes i make
---------------------------------------------------------------------
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
