Hi all,

I've ran some stds for NH3 using an auto analyzer, but the results are not good.

I followed SKALAR (brand of the machine) protocol as well as the one from SEAL, however both results are bad. I made a 1000ppm stock solution and a 10ppm std from the previous one. Consequently, from the 10ppm I made 1; 0,8; 0,6; 0,4 and 0,2 ppm stds.

As you can see from the figure, the 10ppm peak is good, however the other 5 have a weird shape before they reach the maximum height. I was wondering what is causing this as I did different chemical solutions as well as the stds more than once just to check...

Thanks in advance!