Hach DR/700 Procedures Manual page 705

PHOSPHORUS, REACTIVE,
PRECISION
DR/700: In a single laboratory, using a standard solution of
3-
4.20 mg/L PO and two lots of reagent with a DR/700, a single operator
4
obtained a standard deviation of ±0.11 mg/L PO
SAMPLE DISPOSAL INFORMATION
The phosphate vials contain only materials that are non-regulated for
disposal. Neutralize the vial solutions to a pH of 6-9 and dispose as a
normal non-regulated material.
SUMMARY OF METHOD
Orthophosphate reacts with molybdate in an acid medium to produce a
Phosphomolybdate complex. Ascorbic acid then reduces the complex,
giving an intense molybdenum blue color.
REQUIRED REAGENTS
Description
PhosVer 3 Phosphate Reagent
Powder Pillows, 10 mL . . . 1 Pillow . . . 100/pkg . . . . . . . 21060-69
REQUIRED APPARATUS
Test 'N Tube Cuvette Vials. . . . 1 . . . . . . . . . . 25/pkg . . . . . . . . . 25831-25
COD Reactor, 120/240 Vac . . . 1 . . . . . . . . . . each . . . . . . . . . . . 45600-00
COD Vial Adapter, DR/700 . . . 1 . . . . . . . . . . each . . . . . . . . . . 46008-00
DR/700 Filter Module 81.00. . . 1 . . . . . . . . . . each . . . . . . . . . . . 46281-00
Funnel, micro. . . . . . . . . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 25843-35
Pipet, volumetric,
Class A, 2 mL . . . . . . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 14515-36
Pipet, volumetric,
Class A, 4 mL. . . . . . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 14515-04
Pipet, volumetric,
Class A, 5 mL . . . . . . . . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 14515-37
Pipet Filler, safety bulb . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 14651-00
Safety Shield,
laboratory bench. . . . . . . . . . 1 . . . . . . . . . . each . . . . . . . . . . . 23810-00
Test Tube Rack . . . . . . . . . . . . . 1-3 . . . . . . . . each . . . . . . . . . . . 18641-00
OPTIONAL REAGENTS
Hydrochloric Acid Standard Solution,
6.0 N (1:1) . . . . . . . . . . . . . . . . . . . . . . 500 mL . . . . . . . . . 884-49
Mercuric Chloride Solution, 10 g/L . . . . . . . 100 mL . . . . . . . 14994-42
continued
4
Quantity
Per Test Unit
81-31
3-
.
Cat. No.