[piponev]

Hello,

I have a very specific question regаrding chlorine (and eventually chloroform) present in drinking water. I am not a chemist, so that's why I am searching help here.

Is there a harmless substance that can be added to drinking water, so that it makes a reaction only with the chlorine/chloroform in it? Or, just a weak reaction with other substances in drinking water but a strong one with chlorine/chloroform (if present, of course)? Also, the substances resulting from the reaction should also be as harmless as possible. Can anyone suggest such a substance? I am looking for something harmless to health and easily obtainable. Can anybody suggest something like that?

Thank you very much in advance!

[Arkcon]

I'm expecting the reaction you mean is some sort of color change that can be easily seen with the naked eye.  To put it as simply as I can, you can't expect such a reaction, with the levels of chlorine usually found in municipal tap water, much less likely for chloroform levels.  They do sell visible, colormetric tests, for pool chlorine or other disinfecting levels of chlorine.

Failing that, there are laboratory tests for trace levels of chemicals, that will test water for a fee.  But they work on contract with companies, they simply won't take your tap water because you're curious.  Not at any price.  Which will be a high one, if they're under contract.

[wildfyr]

I actually came up with a reasonable chloride test using the turbidity/UV Vis of a solution after adding silver nitrate and a little nitric acid to get chloride concentration. Its far from perfect (some others ions can interfere, and the range is narrow), but you can at least get an idea of concentration if you do thoughtful dilutions. Otherwise you need ion chromatography (IC) for chloride. My technique gave a value of 12 ppm and IC said 30 for a sample, so I felt pretty good about that. My range was 0-25 ppm.

For chloroform, you need a GC/MS.