Hach DR/700 Procedures Manual page 8

PHOSPHORUS, REACTIVE,
4.
the 10-mL line with
sample.
Note: For proof of
accuracy, use a 1.0 mg/L
Phosphate (0.33 mg/L P)
Standard Solution (listed
under Optional Reagents)
following these steps, in
place of the sample.
Additional
Note: Run a reagent blank
information
for this test. Use deionized
that may be
water in place of the
applicable
sample in Step 4. Subtract
this result from all test
results run with this lot of
PhosVer.
Note: Optional 25-mL
reagents sample may be
used (see Optional
Reagents).
Illustration of
procedure steps
and instrument
keystrokes
required
5.
Fill a 10-mL cell to
one PhosVer 3
Phosphate Powder
Pillow to the sample
cell (the prepared
sample). Cap and
invert several times to
mix.
Note: A blue color will
form if phosphate is
present.
continued
2 minutes
6.
Add the contents of
Note: An 8-10 minute
reaction period should be
used if determining total
phosphate following the
acid-persulfate digestion.
Note: If the sample
temperature is less than
O
15
minutes of reaction time.
81-48
viii
Wait two minutes.
O
C (59 C), allow 9