Hach DR/700 Procedures Manual page 450

CHROMIUM, HEXAVALENT,
4.
Fill a 10-mL cell
to the 10-mL line
with sample.
Note: A 25-mL sample
can be tested by using
25-mL sample cells and
optional reagents.
Note: For proof of
accuracy, use a
0.25 mg/L hexavalent
chromium standard
solution (preparation
given in the Accuracy
Check) in place of the
sample.
5.
Add the contents
of one ChromaVer 3
Reagent Powder
Pillow to the cell (the
prepared sample).
Cap. Invert several
times to mix.
Note: A purple color
will form if hexavalent
chromium is present.
Note: At high chromium
levels a precipitate will
form. Dilute sample
according to Sample
Dilution Techniques
(Section 1).
Note: ChromaVer 3
Reagent should be white
to tan in color. Replace
if it is green or brown.
55-2
continued
5 minutes
6.
Wait 5 minutes.