[quiminoob]

Dear forum.
I am making a kit for the determination of chlorite in water, the problem is that I am not sure if the reacctions that i think are happening are correct, for the solutions i am using calcium hypochlorite and as indicators citric acid and potassium iodide.

The idea is that the citric acid reacts with the hypochlorite generating chlorine dioxide and this oxidizes the iodide to form iodine that dyes the solution, I do not know if this is correct or not if someone can, please help me.

I also tried to determine the chlorite by the DPD method using  sodium chlorite standard, but it does not work. It seems that the chlorite does not give the pink color with DPD as the free chlorine or chlorine dioxide do, and the other I found is with iodine.

I would appreciate very much if someone could help me. 

[chenbeier]

Principle it can work. But citric acid is an organic acid and can react with clorined ioxide, chlorine and also iodine by oxidation, so the result will be not exact.  So better is to use sulfuric acid or hydrochloric acid instead.