Hach DR/850 Procedures Manual page 268

NITROGEN, AMMONIA, Low Range, Test 'N Tube,
Interfering Substance
Sulfide
Other
Summary of Method
Pollution Prevention And Waste Management
REQUIRED REAGENTS
AmVer Reagent Set for Nitrogen, Ammonia, Low Range TNT (25 tests)................... 26045-45
Includes: (1) 23952-66, (1) 23954-66, (1) 272-42,
Description
AmVer Diluent Reagent, Low Range Test 'N Tube ... 2 vials ............... 50/pkg....................... *
Salicylate Reagent Powder Pillows, 5 mL sample .... 2 pillows ............. 50/pkg.......... 23952-66
Cyanurate Reagent Powder Pillows, 5 mL sample.... 2 pillows ............. 50/pkg.......... 23954-66
* Not available separately.
Interference Level and Treatment
1. Measure about 350 mL of sample in a 500 mL erlenmeyer flask.
2. Add the contents of one Sulfide Inhibitor Reagent Powder Pillow. Swirl to mix.
3. Filter the sample through a folded filter paper.
4. Use the filtered solution in step 4.
Less common interferences such as hydrazine and glycine will cause intensified
colors in the prepared sample. Turbidity and color will give erroneous high
values. Samples with severe interferences require distillation. Hach recommends
the distillation procedure using the Hach General Purpose Distillation Set. See
Optional Apparatus at the end of this procedure.
Ammonia compounds combine with chlorine to form
monochloramine. Monochloramine reacts with salicylate to form
5-aminosalicylate. The 5-aminosalicylate is oxidized in the
presence of a sodium nitroprusside catalyst to form a blue-
colored compound. The blue color is masked by the yellow color
from the excess reagent present to give a final
green-colored solution.
The ammonia salicylate reagent contains sodium
nitroferricyanide. Cyanide solutions are regulated as hazardous
wastes by the Federal RCRA. Collect cyanide solutions for
disposal as reactive (D001) waste. Be sure cyanide solutions are
stored in a caustic solution with pH >11 to prevent release of
hydrogen cyanide gas. See Section 3 for further information in
proper disposal of these materials.
268
*
(50) AmVer Low Range Vials
Quantity Required
Per Test
continued
Cat. No.
Unit Cat. No.