Hach DR2400 - Page 623

Phosphorus, Reactive (Orthophosphate)
Phosphorus, Reactive (Orthophosphate)
PhosphorusReac_None_Other_AMI_Eng_Ody.fm Page 5 of 6
Summary of Method
In a highly acidic solution, ammonium molybdate reacts with orthophosphate to
form molybdophosphoric acid. This complex is then reduced by the amino acid
reagent to yield an intensely colored molybdenum blue compound. Test results
are measured at 530 nm.
Required Reagents
Quantity Required
Description Per Test Unit Cat. No.
High Range Reactive Phosphorus Reagent Set.............................................................. 100 tests.............22441-00
Includes:
Amino Acid Reagent .........................................................................1 mL ................ 100 mL MDB.......1934-32
Molybdate Reagent............................................................................1 mL ................ 100 mL MDB.......2236-32
Required Apparatus
Cylinder, 25-mL, graduated, mixing......................................................1 ....................... each......................1896-40
Sample Cells, 10-20-25 mL, w/cap.........................................................2....................... 6/pkg.................24019-06
Required Standards
Phosphate Standard Solution, 10-mg/L.......................................................................... 946 mL...............14204-16
Phosphate Standard Solution, 2-mL Voluette
®
Ampule, 500-mg/L PO
4
3–
............... 16/pkg...............14242-20
Water, deionized ................................................................................................................. 4 liters ....................272-56