YSI 9300 Photometer - Manual (Page 83)

PHOTOMETER TEST INSTRUCTIONS
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Nitrites are found in natural waters as an intermediate product in the nitrogen
cycle. Nitrite is harmful to fish and other forms of aquatic life and the nitrite
level must be carefully controlled in water used for fish farms and aquariums.
The nitrite test is also applied for pollution control in waste waters, and for the
monitoring of drinking water.
The YSI Nitricol test provides a simple method of measuring Nitrite Nitrogen
levels over the range 0 - 0.5 mg/l N. Higher levels can be determined by diluting
the sample.
Method
Nitrites in acid solution react with sulphanilic acid. The resulting diazo compound
couples with N-(1-naphthyl)-ethylene diamine to form a reddish dye. The YSI
Nitricol method features a single tablet reagent containing both of these
reagents in an acidic formulation. The test is simply carried out by adding a
tablet to a sample of the water under test.
The intensity of the color produced in the test is proportional to the nitrite con-
centration and is measured using a YSI Photometer.
Reagents and Equipment
YSI Nitricol Tablets
YSI 9300 or 9500 Photometer
Round Test Tubes, 10 ml glass (PT 595)
Photometer Method
AUTOMATIC
WAVELENGTH
SELECTION
0 – 0.5 mg/l N
(0 – 1.6 mg/l NO
2
)
PHOT.24.AUTO