Hach DR/850, Procedures Manual, Page: 371 / 460

371
Method 8180
PHOSPHORUS, ACID HYDROLYZABLE
(0.00 to 5.00 mg/L PO
4
3- )
PhosVer 3 with Acid Hydrolysis
For water, wastewater, and seawater
Test ’N Tube
™
Procedure
1.
Turn on the COD
Reactor. Heat to 150 °C.
Note: See DRB200
instrument manual for
selecting preprogrammed
temperature applications.
2.
Enter the stored
program number for acid
hydrolyzable phosphorus
(PO
4
3-
), Test ‘N Tube.
Press:
PRGM
The display will show:
PRGM ?
Note: For most accurate
results, perform a Reagent
Blank Correction using
deionized water (see
Section 1).
3.
Press:
82 ENTER
The display will show
mg/L, PO4 and the
ZERO icon .
Note: For alternate forms
(P, P
2
O
5
), press the
CONC key.
4.
Insert the COD/TNT
Adapter into the cell
holder by rotating the
adapter until it drops into
place. Then push down
to fully insert it.
Note: A diffuser band
covers the light path holes
on the adapter to give
increased performance.
The band should NOT be
removed.
5.
Use a TenSette Pipet
to add 5.0 mL of sample
to a Total and Acid
Hydrolyzable Test Vial.
Cap and mix.
6.
Heat the vial in the
DRB200 Reactor for
30 minutes.
7.
Carefully remove the
vial from the reactor.
Place it in a test tube
rack and allow to cool to
room temperature.
Note: Vials will be hot.
8.
Remove the cap from
the vial. Use a TenSette
Pipet to add 2.0 mL of
1.00 N sodium
hydroxide to the vial.
Cap and mix.