Hach DR/700 Procedures Manual page 198

HYDRAZINE,
4.
Pour 10.0 mL of
demineralized water
into a 10-mL sample
cell (the blank) using
a graduated cylinder.
12 minutes
7.
Wait 12 minutes.
Note: Complete Steps 8
through 10 during this
time.
continued
5.
Pour 10.0 mL of
sample into a second
10-mL sample cell
(the prepared sample)
using a graduated
cylinder.
Note: For proof of
accuracy, use a 100 µg/L
hydrazine standard
solution (preparation
given in Accuracy
Check) in place of the
sample.
Note: Sample
temperature should be
21°C ± 4°C (70°C ± 7ºF).
8.
Place the blank in
the cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
45-26
6.
Add 0.5 mL of
HydraVer 2
Hydrazine Reagent to
each sample cell.
Cap and invert several
times to mix.
Note: A yellow color
will develop if hydrazine
is present.
Note: HydraVer 2
Reagent will cause a
faint yellow color to
appear in the blank.
9.
Press:
ZERO
The display will
count down to 0.
Then the display will
show 0.00 µg/L and
the zero prompt will
turn off.