TM 10-6630-245-13&P
2.6.8.15. Nitrogen as Nitrates Test.
a.
Purpose of Test: To determine the amount of nitrogen present in a water sample as nitrates.
b.
Range: 0.0 to 30.0 mg/l
c.
Equipment Used: Found in Main Carrying Case, para 1.8, fig. 1-1
Spectrophotometer, (20), fig. 1-1
Nitrate (NitraVer® 5) reagent, (24), fig. 1-1
Graduated cylinder, (31), fig. 1-1
d.
General Techniques Used: Refer to paragraphs cited below as required by procedure.
Planning the Test, para 2.6.1.1
Cleaning Glassware, para 2.6.1.2
Handling and Storing Reagents, para 2.6.1.3
Collecting Water Samples, para 2.6.1.4
Mixing, para 2.6.1.5
Using Graduated Cylinders, para 2.6.1.6
Spectrophotometer, para 2.6.2.2
e.
Test Procedure:
WARNING
High voltage used with Spectrophotometer. Misuse can cause electrical shock and damage
equipment. When operating with 115V or 220V power, make sure the power source and
equipment are in ground potential. Ensure that the power cable connections are correct for the
desired voltage power before connecting the power source.
NOTE
The nitrate reagent is slightly temperature sensitive. For best results, the test should be done
with a sample temperature of 68-75°F (20-25 °C).
(1)
Refer to para 2.6.2 for setup and operation of the Spectrophotometer.
(2)
Fill each of the two spectrophotometer sample cells(7, fig. 2-5) with 25 ml of sample water. Use the
graduated
cylinder(31, fig. 1-1) to collect and measure the water.
WARNING
NITRATE (NITRAVER® 5) REAGENT
May be irritating to eyes, skin and respiratory tract. Harmful if swallowed. Do not ingest or allow contact with skin or
eyes. Do not breathe dust. In case of contact, immediately flush eyes with water for 15 minutes. Remove contaminated
clothing. Wash skin with soap and plenty of water. In case of ingestion, give milk or beaten eggs at frequent intervals.
Induce vomiting. In case of inhalation, remove victim to fresh air. Call medic in all cases.
(3)
To one filled sample cell(7, fig. 2-5), add the contents of one nitrate reagent powder pillow(24, fig. 1-1).
This is the treated sample.
NOTE
A deposit of unoxidized metal will remain after the nitrate reagent powder has dissolved. This
will not affect test results.
(4)
Shake the treated sample vigorously for exactly one minute. An amber color will develop if nitrate nitrogen
is present.
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