Hach DR/700 Procedures Manual page 276

NITRATE, HR,
4.
Fill a 10-mL cell
to the 10-mL line
with sample.
continued
5.
Add the contents
of one NitraVer 5
Reagent Powder
Pillow to the cell (the
prepared sample).
Cap.
50-26
1 minute
6.
Shake the cell
vigorously for one
minute.
Note: A deposit of
unoxidized metal will
remain after the
NitraVer 5 Nitrate
Reagent Powder
dissolves. The deposit
will not influence test
results.
Note: Shaking time and
technique influence
color development. For
most accurate results,
make successive tests on
a
10 mg/L Nitrate
Nitrogen Standard
Solution (listed under
Optional Reagents).
Adjust the shaking time
to obtain the correct
result.
Note: An amber color
will develop if nitrate
nitrogen is present.