2429700 Phosphonate Reagent Set, 0.02-125 mg/L PO₄

Phosphonate Reagent Set measures phosphonate in the range from 0.02 to 125 mg/L PO₄ in boiler water, cooling water and other liquids. The product uses Persulfate UV Oxidation method (8007). Article 2429700 can be used to evaluate up to 100 samples. The product is compatible with all Hach spectrophotometers or colorimeters except DR820.

Phosphonate Reagent Set includes:

• PhosVer 3 Phosphate Reagent Powder Pillows (p/n 2106069)
• Potassium Persulfate Reagent Powder Pillows (p/n 2084769)

Before starting analysis:

• Collect the sample with glass or plastic container cleaned with 6 N (50%) hydrochloric acid and rinsed with deionized water.
• It is recommended to rinse and wipe the UV lamp using soft, clean tissue after each measurement.
• It is required to increase the sample temperature to room temperature and adjust the pH to 7 with 5 N sodium hydroxide solution before sample analysis.

Procedure for PO₄ determination

Run program 501 Phosphonates. Add 10mL of the diluted sample in the cell to prepare the blank. Mix 25mL of the diluted sample and Potassium Persulfate Reagent Powder Pillow in the mixing bottle. Place the ultraviolet lamp in the mixing bottle and turn on the UV lamp. After 10 minutes, turn off the UV lamp and remove it from the mixing bottle. Fill another cell to with 10mL of the digested sample. Pour the content of one PhosVer 3 Phosphate Reagent Powder Pillow to the cell blank. Add PhosVer 3 Phosphate Reagent Powder Pillow to the pretreated sample cell. Swirl each cell and evaluate using spectrophotometer (at 880 nm) or colorimeter (at 610 nm).

Summary of method

The orthophosphate enters into reaction with the molybdate in the PhosVer 3 reagent formin mixed phosphate/molybdate complex. This complex is reduced by the ascorbic acid in the PhosVer 3 that gives a blue color proportional to the phosphonate concentration. The orthophosphate is removed after the blank is used to set the zero concentration.

Sample preparation

The required storage temperature of the product is between 10 °C and 25 °C.