Figure 1.
In-tube hydrogel test kits for (a) nitrite, (b) nitrate, and (c) phosphate detection and the colorimetric products obtained from the testing of standard solutions with the (d) nitrite, (e) nitrate, and (f) phosphate test kits.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.