Section 5 Bench Method Procedure; Standardization; Standardization Procedure - Hach APA 6000 Operation Manual

Section 5

5.1 Standardization

5.2 Standardization Procedure

1. Fill a 25-mL buret with
Reagent 3. This will be
used to titrate in step 6.
5. Using a graduated
cylinder, add 8 mL of
Reagent 2. Swirl to mix.
Note: Prepare Reagent 2 by
mixing one bottle of Indicator
Powder into 1 L of Buffer
Solution. Reagent 2 can then
be kept for approximately
3 months.
6200018bench.fm
Bench Method Procedure
Standardize Reagent 3 with Standard 2 (1000 mg/L as CaCO
the titer value of Reagent 3 before testing samples for total hardness. Perform
a standardization before any sample analysis, as reagents may change
over time.
2. Use a volumetric pipet
to transfer 20.00 mL
of Standard 2 solution
into a clean 250-mL
Erlenmeyer flask.
6. Swirl the flask while
titrating with Reagent 3
from red to pure blue.
3. Dilute to about the
100-mL mark with
deionized water.
7. Record the volume of
Reagent 3 required.
Reagent 3 Titer (M)
) to determine
3
4. Using a marked
dropper, add 1 mL of
Reagent 1.
Swirl to mix.
8. Calculate the titer of
Reagent 3 using the
equation below:
0.2
= -------------------------------------------------------------- -
Reagent 3 Volume (mL)
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Bench Method Procedure