I am designing an automated system testing device for my high school's aquaponics club. We need to test for a number of ion concentrations, including ammonia and nitrite/nitrate. In my research, the few selective-ion probes that exist are quite expensive, thus I am looking for some other, more creative methods for attaining these concentrations.

The most obvious method of testing would be to use a colorimeter to assess water samples w/added indicators. However, this would be a fairly complex device to automate. I would essentially be building an autosampler, which I think would be a ton of fun, but has the disadvantage of being expensive and time-consuming (to an extent that my application writing will not allow).

My question to you, community, is if I could test concentrations of these ions through vaporizing my sample and testing vapor w/gas sensors. If I were to boil a solution containing nitrite, nitrate and ammonia, what would my products be? Could I theoretically pull this off?

Thanks! Ethan

  • $\begingroup$ You'll never be able to use your method for ammonia. It'll evaporate off with whatever you boil off. My guess is that the overall concentrations of salts is quite low and there are other salts, so you're going to have trouble with any kind of gravimetric analysis. Theoretically, it's possible, but in practice, with what you're suggesting, I suspect you'll have a hard time. $\endgroup$
    – Zhe
    Oct 19, 2016 at 20:08
  • $\begingroup$ There are testing kits for aquariums that do what you're trying to do. Look up the chemistry of those kits. $\endgroup$ Oct 20, 2016 at 7:41


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