Quote:
Originally Posted by jrhupp
If you are going that route, why not just measure alkalinity with an automated colorimetric test?
There should be some visible dye suitable for this. I know we typically use a titration method (and that seems the approach used in the automated monitors coming out). But I am pretty Hatch or somebody along those lines make a single reagent that segregates into two forms with different peak absorption wavelengths in the visible spectrum based on alkalinity.
|
I have been researching the various methods of performing alkalinity tests, and the reason I was following this thread. Along the way I ran across a paper that described a system to perform alkalinity testing using Spectrophotometry and a reagent with a known absorption profile. Then a small amount of the sample was added and the resulting PH shift was used to calculate the alkalinity concentration to achieve the shift. It was quite interesting, but did require removing the carbolic acid from the sample by flowing the sample through a gas permeable hose in a NaOH bath. I am not sure if the added complexity is worth it though.
I am leaning towards doing a regular titration with a colorimeter to detect the end point. To get around the issues with volume accuracy, I plan to use a load cell to calculate the various weights of the sample and reagent rather than try to keep pumps from drifting.
Dennis