Hach DR2400 Manual page 525

Method Performance
Summary of Method
Required Reagents
Description
Nitrogen Reagent Set, 0–150 mg/L, Nesslers Method.................................................. 250 tests ...........24953-00
Includes:
Hydrogen Peroxide, 50% .................................................................. 20 mL .............. 490 mL...............21196-49
Mineral Stabilizer ............................................................................... 6 drops............ 50 mL SCDB .....23766-26
Nesslers Reagent ................................................................................ 2 mL ................ 500 mL...............21194-49
Polyvinyl Alcohol Dispersing Agent .............................................. 6 drops............ 50 mL SCDB .....23765-26
Potassium Hydroxide Standard Solution, 1.0 N ........................... varies .............. 50 mL SCDB .....23144-26
Potassium Hydroxide Standard Solution, 8.0 N ........................... varies .............. 100 mL MDB.........282-32
Sulfuric Acid, ACS, concentrated .................................................... 6 mL ................ 500 mL...................979-49
TKN Indicator Solution..................................................................... 2 drops............ 50 mL SCDB .....22519-26
Required Apparatus
Boiling Chips, silicon carbide ................................................................. 2–3 ................... 500 g...................20557-34
Cots, finger ................................................................................................ 2 ....................... 2/pkg.................14647-02
Cylinder, graduated mixing, 25-mL....................................................... 2 ....................... each....................26362-40
Select one based on available voltage:
®
Digesdahl Digestion Apparatus, 115 VAC................................... 1 ....................... each....................23130-20
®
Digesdahl Digestion Apparatus, 220 VAC................................... 1 ....................... each....................23130-21
®
Pipet, TenSette , 0.1–1.0 mL.................................................................... 1 ....................... each....................19700-01
Pipet Tips, for 19700-01 TenSette
Safety Shield .............................................................................................. 1 ....................... each....................50030-00
Sample Cells, 10-mL, w/cap................................................................... 2 ....................... 6/pkg.................24276-06
Required Standards
Nitrogen Standard Solution, 1-mg/L NH
Nitrogen Standard Solution, Voluette
NitrogenTK_None_Other_NES_Eng_Ody.fm
Precision
Standard: 120 mg/L NH
Program
399
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
Portion of Curve
Entire range
See Section 3.4.5 Sensitivity on page 44 for more information.
The term Total Kjeldahl Nitrogen refers to the combination of ammonia and
organic nitrogen. However, only the organic nitrogen compounds appearing as
organically bound nitrogen in the trinegative state are determined in this test.
Nitrogen in this form is converted into ammonium salts by the action of sulfuric
acid and hydrogen peroxide. The ammonia is then analyzed by a modified
Nessler method test. Test results are measured at 460 nm.
®
Pipet ............................................... 2 ....................... 50/pkg...............21856-96
–N................................................................ 500 mL.................1891-49
3
®
Ampule, 10-mL .............................................. 16/pkg...............21284-10
Nitrogen, Total Kjeldahl
–N
3
95% Confidence Limits of Distribution
107–133 mg/L NH
∆Abs
0.010
Quantity Required
Per Test
–N
3
∆Concentration
1 mg/L NH –N
3
Unit Cat. No.
Nitrogen, Total Kjeldahl
Page 5 of 6