Hach DR2400 - Page 641

DR/2400
Phosphorus, Reactive (Orthophosphate)
PhosphorusReac_AVPP_Other_PV3_Eng_Ody.fm Page 1 of 6
• For more accurate results, determine a reagent blank value for each new lot of reagent. Follow the procedure using deionized
water in place of the sample. Subtract the reagent blank value from the final results or perform a reagent blank adjust. See
Section 2.6.2 Reagent Blank on page 20 for more information.
• A blue color will develop if phosphorus is present.
• Wipe the outside of sample cells before each insertion into the instrument cell holder. Use a damp towel followed by a dry one to
remove fingerprints or other marks.
Phosphorus, Reactive
(Orthophosphate)
(Method 8048
PhosVer 3 (Ascorbic Acid) Method*
*Adapted from Standard Methods for the Examination of Water and Wastewater
Powder Pillows or AccuVac
®
Ampuls
(0.02 to 2.50 mg/L PO
4
3–
)
Scope and Application: For water, wastewater, and seawater; USEPA Accepted for reporting for
wastewater analyses**
** Procedure is equivalent to USEPA method 365.2 and Standard Method 4500-P-E for wastewater.
1. Touch
Hach Programs.
Select program
490 P React. PV.
Touch
Start.
2. Fill a sample cell with
10-mL of sample.
3. Add the contents of
one PhosVer 3 phosphate
Powder Pillow to the cell.
Immediately cap and
invert to mix (this is the
prepared sample).
4. Touch the timer icon.
Touch
OK.
A two-minute reaction
period will begin.
If the sample was digested
using the Acid Persulfate
digestion, a ten-minute
reaction period is
required.
Tips and Techniques
Powder Pillows Method 8048
Hach Programs