[zakaria]

Hello everyone,

can somebody explain to me the reason why does my Potassium Iodide Starch Paper turn brown when I check my waste countainer (this countainer is just for Peroxid number Test waste) and it countains oil samples, Decan1ol, acetic acid, potassium iodid (which I use to titrate peroxids in my oil samples) and water and Hydrogen chloride.
Theoretically, the peroxids are titrated (consumed) by the KI. I do not find an explanation to the fact that my KI paper indicates the presence of peroxids in my waste.
I am all ears (eyes)  and glad to hear your theories or answers.

Thank you in advance!

[Hunter2]

Did you check the paper only with Peroxide. Did you got a darf blue colour?

[rjb]

I should probably start by saying that until today, I'd never heard of KI Starch Paper, but the problem intrigued me, so I looked it up!

From what I gather the paper changes colour in the presence of oxidising agents (like peroxides) but also others like free Chlorine and Iodine.
Given that your waste container contains KI and HCL, could this be generating free Iodine perhaps? 

Just a thought...