Hach DR/700 Procedures Manual page 238

LEAD,
continued
4.
Use a second
1-mL plastic dropper
to add 2.0 mL of
pPb-2 Fixer Solution
to the sample. Swirl
to mix and proceed
quickly to the next
step.
Note: Field samples
that have been acid-
preserved with nitric
acid or samples that
have been digested may
exceed the buffer
capacity of the Fixer
Solution. After step 4
check the pH of these
samples and adjust with
5 N sodium hydroxide to
a pH of 6.7-7.1 before
proceeding with Step 5.
5.
Mount a new Fast
Column Extractor in
a ring stand with a
clamp. Place a
150-mL plastic
beaker under the
Extractor.
Note: Fast Column
Extractor is included in
the LeadTrak Reagent
Set.
Note: A new extractor is
required for each test.
48-2
6.
Pour the prepared
sample slowly into
the Column
Extractor. Wait for
the sample to flow
through.