Ammonia Nitrogen
DR/700 Instructions
Equipment
Procedure
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Before Going to the Field
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Hach DR/700 Colorimeter
Module 61.01
25 mL Sample Vials
Ammonia Cyanurate Reagent Powder
Pillows (for 10 mL sample)
Ammonia Salicylate Reagent Powder
Pillows (for 10 mL sample)
Material Safety Data Sheets (MSDS)
Goggles and Gloves
Waste Container – “Ammonia Waste
Only”
Deionized or Distilled Water
Stopwatch or Timer
Ammonia Nitrogen Data Sheet
Safety Note
The ammonia nitrogen test requires the use
of ammonia cyanurate and ammonia
salicylate. Both of these reagents should be
treated as toxic chemicals. This test should
be performed well away from the stream.
Avoid contact with all reagents. If any
reagent gets onto your hands, rinse
thoroughly with water. More detailed
information can be found on the Material
Safety Data Sheet (MSDS) for each reagent.
About This Test
Ammonia nitrogen should be measured in
the field immediately after sampling. In the
presence of oxygen, ammonia can be
converted to nitrate.
The ammonia reaction is extremely time
sensitive – all replicates should be read
immediately when the reaction time is
finished. For best results, reagents should
not be added to all replicates at the same
time. Staggering the reagent addition by 30
seconds or a minute (see the Ammonia
Reaction Timetable) allows each sample to
be read after the 15 minute reaction time.
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1. Make sure all sample vials used for this
test have been acid washed and
thoroughly rinsed with distilled or
deionized water.
2. Find any previous data available for this
site. Enter recent data (preferably from
the same time of year) in the “Previous
Data From This Site” section on the
Ammonia Nitrogen Data Sheet.
3. Use this data to determine what range of
values to expect from this site.
Salicylate Procedure
(0 – 1.00 mg/L NH3-N, Method 8155)
1. Fill 3 - 5 sample vials to the 10 mL line
with the sample water to be tested.
2. Fill another sample vial to the 10 mL
line with deionized water to be used as
the blank.
It is very important that the deionized
water used for this step be pure.
3. Beginning with the blank, add one
Ammonia Salicylate Reagent Powder
Pillow to each vial – wait at least 30
seconds between adding reagent to
each sample. Cap each vial and shake
until the reagent has dissolved.
Using the Ammonia Reaction Timetable
is recommended.
4. Let each sample sit for 3 minutes.
5. After 3 minutes, add one Ammonia
Cyanurate Reagent Powder Pillow to
each vial (including the blank). Cap
each vial and shake until the reagent has
dissolved.
6. Let each sample sit for 15 minutes.
Ammonia DR/700 Instructions
Nitrogen  Page 25
Ammonia Nitrogen
The treated blank will develop a yellow
color. The samples should develop color
with at least the same intensity as the
blank. A green color will form if the
ammonia concentration is high.
7. Place the 61.01 module in the base of the
DR/700 colorimeter. Push firmly so that
the module snaps into place.
DR/700 Instructions
11. Place a film canister or other cover over
the top of the vial to keep ambient light
from interfering with the sample reading.
12. At the end of the 15-minute reaction
period, press ZERO to measure the
blank. The display will count down
from 20 and then read 0.0 mg/L.
13. Remove the blank.
Lamp Intensity Adjustment:
Running the lamp intensity adjustment any
time a different module is inserted into the
DR/700 will improve test result accuracy.
14. Wipe off the outside of the sample vial
for each replicate and insert the vial into
the cell holder on the colorimeter. Cover
the sample.
1. Fill a sample vial with deionized water.
Wipe off the outside of the vial and
place it into the cell holder.
15. Press the READ button and allow the
display to count down from 20.
2. While the colorimeter is off, press and
hold the READ button and then turn on
the colorimeter. Continue pressing the
READ button until “–L” appears in the
lower part of the display.
3. Release the READ button and the
display will count down from 20. The
lamp will light and then the lamp will
automatically adjust to the optimum
setting. The adjustment is complete
once the lamp icon turns off.
4. Press the Program key or turn off the
colorimeter to return to the normal
menu.
8. Turn the DR/700 Colorimeter on by
pressing the I/O button.
9. Use the arrow keys to adjust the program
number on the display to 61.06.1.
This step is very important – it sets the
colorimeter to use the calibration
information for the correct method.
10. Wipe off the outside of the vial
containing the blank and insert the vial
into the cell holder on the colorimeter.
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16. Record the readings directly from the
colorimeter and report it on the
Ammonia Data Sheet.
17. At the end of each replicate, pour the
sample with reagent into the Ammonia
Waste Only waste container. Rinse the
vial three times with deionized water and
pour the rinsings into the waste
container.
18. You need 3 - 5 final values for each test.
If you suspect an error in a given rep
(spilled reagent, contamination, etc.) do
not include this rep and make a note in
the Comment section indicating why it
was discarded. Place a checkmark next
to the reps used to calculate the average.
Reporting Results
Ammonia results should be reported in units
of mg/L as N. Results listed in units of
mg/L NH3 can be converted to mg/L N by
multiplying by 0.822.
Federal water quality standards for ammonia
are based on the level at which ammonia
becomes toxic to fish and aquatic life.
Ammonia toxicity is dependent upon
temperature and pH:
Ammonia DR/700 Instructions
Nitrogen  Page 26
Ammonia Nitrogen
Max
Max
Conc.
Conc.
(salmonid (salmonid Continuo
present)
absent)
us Conc.
NH3-N
NH3-N
NH3-N
pH
(mg/L)
(mg/L)
(mg/L)
6.5
32.5
48.8
3.48
7.0
24.0
36.1
3.08
7.5
13.3
19.9
2.28
8.0
5.60
8.40
1.27
8.5
2.13
3.20
0.57
9.0
0.88
1.32
0.25
From EPA’s 1998 Update of Ambient Water
Quality Criteria for Ammonia
In addition to standards based on ammonia
toxicity, some watersheds have TMDL’s
established for ammonia to control
nitrogenous biochemical oxygen demand.
Specific bacteria can convert ammonia to
nitrate, which can deplete the dissolved
oxygen in a stream or river.
Ammonia nitrogen concentrations in the
Portland/Vancouver metropolitan area have
historically been less than 0.5 mg/L NH3-N,
with a few streams measuring up to 1.1
mg/L NH3-N. Most streams routinely have
concentrations near the detection limit of
this method, 0.03 mg/L NH3-N. Clean
glassware (acid washed and well rinsed) and
the use of pure deionized water is critical for
this test. Deionized water contaminated
with ammonia can turn green, just like the
samples.
Ammonia concentrations should be reported
to two decimal places (i.e. to the nearest
0.01 mg/L N). The standard deviation for
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DR/700 Instructions
the ammonia nitrogen method on the
DR/700 is + 0.006. The range for replicates
should not vary by more than 0.03 mg/L
NH3-N. The variability between replicates
is referred to as the “precision” of your
technique. To calculate the precision of
your replicates, subtract the lowest value
replicate (minimum) from the highest
(maximum).
Target Precision
Example:
Replicates
Range
Maximum
Minimum
Precision
0.03 mg/L
0.02, 0.05, 0.04, 0.04,
0.02
0.02 – 0.05
0.05
0.02
0.03
Waste Disposal
For the ammonia nitrogen test, all waste
should be placed in a separate plastic
container labeled “Ammonia Waste Only”
to be disposed of in the lab. This should
include the excess sample and the solution
from the rinsings.
Ammonia Waste must be disposed of at a
hazardous waste facility. For further
instructions on waste disposal, see the Waste
Management section of this manual.
The waste containers (pillows and packets)
from all chemicals used in the field should
be collected in a Solid Waste Container and
disposed of in the lab.
Ammonia DR/700 Instructions
Nitrogen  Page 27
Time
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Blank
10 mL DI H2O
Add Salicylate
Add Cyanurate
DR/700 Zero
Rep 1
10 mL Stream
Add Salicylate
Add Cyanurate
DR/700 Read
Rep 2
10 mL Stream
Add Salicylate
Add Cyanurate
DR/700 Read
Rep 3
10 mL Stream
Add Salicylate
Add Cyanurate
DR/700 Read
Rep 4
10 mL Stream
Add Salicylate
Add Cyanurate
DR/700 Read
Rep 5
10 mL Stream
Add Salicylate
Add Cyanurate
DR/700 Read
Ammonia DR/700 Instructions
Nitrogen  Page 28
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DR/700 Instructions
Ammonia Nitrogen
Ammonia Reaction Timetable: