Plastic (Tupperware) Absorbing Nitrates?!

[BuddhaReef]

Hey all, weird question!

Does anyone know any chemical reaction that would allow plastic containers to absorb NO3 over about an hour?

I test my water at home and get NO3 at roughly 26. Some mornings I don't have time to test before work, so I collect a sample in a small Tupperware and bring it to work to test (work at a LFS.) The water then tests at roughly 12, after about an hour of transport in plastic.

Test is preformed with the same Hanna HR NO3 checker. I have rechecked both times this has happened, and the results are the same. This happens within the same day, as in;
Test in the AM at work, test reads ~12
Test in the PM, straight from tank, test reads ~26

Thanks for any input!

 

[exnisstech]

Hm interesting and I can't answer. Only thing I will say is I try to be consistent when I test as far as time, containers used to hold samples etc. Also nitrate really isn't important enough to test daily much less take a sample to work to test later unless you have something going on like dosing nitrates maybe which then consistent testing time would be important, at least IMO.

 

[Randy Holmes-Farley]

No, tupperware cannot possibly absorb nitrate.