Does R-0871 evaporate from water?

[Auburn02]

Very random question, but in the midst of my SLAM I've noticed the same thing occur two times and I want to know if it's "normal" or I'm off in my testing. After performing an FAS-DPD test to determine FC, adding the necessary drops of R-0871 until the water in the tube is clear (followed by 5 drops of R-003 and then another drop of R-0871 to return to clear) I went off to add a bit more liquid chlorine and left the water in the tube sitting on my kitchen countertop. Forgetting all about it, I come back to do my next test an hour or two later and low and behold, the sample is pink again. What gives? It was crystal clear after performing the FAS-DPD test, I'm sure of it. Does the R-0871 evaporate or break down, leaving only the pool water with the R-0870 still present? Or did I really not add enough R-0871 in the first place? Note that I am using a speedstir, and it definitely does not turn back to pink within a matter of minutes, only after an extended period.

I'm sure it's no big deal, but I wonder what's actually going on.

 

[Griswald]

The test is only valid when you reach clear. After a very short time, the test is no longer valid, like less than a minute.

Your results were correct.

 

[Newdude]

This has gotten most people at some point. Let he who hasn’t screwed it up cast the first stone. *no stones flying*. See ??

 

[Auburn02]

Cool, thanks. I figured I wasn't completely crazy, still curious about the science behind it but I probably won't understand the technical answer either!