Hach DR/850, Procedures Manual, Page: 265 / 460

265
Method 10023
NITROGEN, AMMONIA, Low Range, Test ‘N Tube
(0 to 2.50 mg/L NH
3
-N)
Salicylate Method
*
For water, wastewater, and seawater
* Adapted from Clin. Chim. Acta, 14 403 (1966).
1.
Enter the stored
program number for low
range nitrogen, ammonia
Test ‘N Tube.
Press:
PRGM
The display will show:
PRGM ?
2.
Press:
66 ENTER
The display will show
mg/L, NH3-N and the
ZERO icon .
Note: For alternate forms
(NH
3
), press the
CONC key.
3.
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: For increased
performance, a diffuser
band covers the light path
holes on the adapter. Do
not remove the diffuser
band.
4.
Remove the caps
from 2 AmVer Diluent
Reagent vials. Add 2 mL
of sample to one vial
(the sample). Add 2 mL
of deionized water to the
other vial (the blank).
Note: Adjust the pH of
stored samples before
analysis. See Interferences
on page 267.
5.
Using a funnel, add
the contents of one
Ammonia Salicylate
Reagent Powder Pillow
for 5 mL sample to each
vial.
6.
Using a funnel, add
the contents of one
Ammonia Cyanurate
Reagent Powder Pillow
for 5 mL sample to each
vial.
7.
Cap the vials tightly
and shake thoroughly to
dissolve the powder.
Note: A green color
will develop if ammonia is
present.
8.
Press:
TIMER ENTER
A 20-minute reaction
period will begin.