Hach DR/700 Procedures Manual page 153

PHOSPHORUS, TOTAL
For water, wastewater and seawater
(also called Organic and Acid Hydrolyzable) Acid Persulfate
Digestion Method*; USEPA accepted for reporting
1.
Measure 25 mL
of sample into a
50-mL erlenmeyer
flask.
Note: Use a graduated
cylinder to measure the
sample.
Note: Rinse all
glassware with 1:1
Hydrochloric Acid
Solution. Rinse again
with demineralized
water.
Note: If prompt analysis
is impossible, see
Sampling and Storage
following these steps.
* Adapted from Standard Methods for the Examination of Water and Wastewater.
2.
Add the contents
of one Potassium
Persulfate Powder
Pillow. Swirl to mix.
42-69
Method 8190
3.
Add 2.0 mL of
5.25 N Sulfuric Acid
Solution.
Note: Use the 1-mL
calibrated dropper
provided.