Hi,

I've been set this piece of work on iodide impurity identification in ammonium bromide. I have so far managed to find 2 lines on this test in European Pharmacopoeia - and I somehow don't think this is going to make up the A4 format required. Basically, it recommends using ferric chloride and methylene chloride solutions for identification and then performing some sort of a colour test. Apparently, two layers are supposed to form and the bottom one needs to be colourless if there is no iodide to be found.

The part I need to find out is whether this test can be quantitative (as opposed to just identifying the impurity present) and the chemical equation for it. Any other information, such as limits of detection as well as other possible tests, will be greatly appreciated.

Many thanks in advance.