Hach DR2400 - Page 437

Nitrate
Nitrate
Nitrate_PP_Low_CDR_Eng_Ody.fm Page 5 of 6
Method Performance
Precision
Standard: 0.2 mg/L NO
3
–
–N
See Section 3.4.3 Precision on page 44 for more information, or if the standard
concentration did not fall within the specified range.
Sensitivity
See Section 3.4.5 Sensitivity on page 44 for more information.
Summary of Method
Cadmium metal reduces nitrates in the sample to nitrite. The nitrite ion reacts in
an acidic medium with sulfanilic acid to form an intermediate diazonium salt.
The salt couples with chromotropic acid to form a pink-colored product. Test
results are measured at 507 nm.
Required Reagents
Quantity Required
Description per test Unit Cat. No.
Low Range Nitrate Reagent Set (100 tests) ..................................................................................................24298-00
Includes:
NitraVer
®
6 Nitrate Reagent Powder Pillows................................1 pillow........... 100/pkg.............21072-49
NitriVer
®
3 Nitrite Reagent Powder Pillows .................................1 pillow........... 100/pkg.............21071-69
Required Apparatus
Cylinder, graduated, mixing, 25-mL......................................................1 ....................... each....................20886-40
Sample Cells, 10-mL, w/cap...................................................................2 ....................... 6/pkg.................24276-06
Required Standards
Nitrate Nitrogen Standard Solution, 10.0-mg/L NO
3
–
–N............................................ 500 mL...................307-49
Nitrate Nitrogen Standard Solution, Voluette
®
Ampule, 12-mg/L NO
3
–
–N............ 16/pkg...............14333-10
Water, deionized ................................................................................................................. 4 liters ....................272-56
Program 95% Confidence Limits of Distribution
351 0.18–0.23 mg/L NO
3
–
–N
Portion of Curve ∆Abs ∆Concentration
Entire range 0.010 0.004 mg/L NO
3
–
–N