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Phosphate, ortho Test Kits

Phosphate, ortho Test Kits

Click on a catalog number in the tables below for more information or to purchase a phosphate test kit.

What is Phosphate?

Phosphorus (chemical symbol P) is the 15th chemical element on the periodic table. It is highly reactive and is rarely found as a free element in nature. It can be found in rock formations in the earth’s crust, usually as phosphate. Phosphate commonly refers to orthophosphate (PO43-) an ionic derivative of phosphoric acid (H3PO4). Various forms of phosphate are used in manufacturing. Phosphoric acid is used widely in manufacturing from foodstuffs to electronics. Since phosphate chelates calcium and magnesium ions, it has been used in detergent formulations to make them more efficient. However, starting in the 1970s, regulations were passed to restrict phosphates in detergents due to environmental concerns. Much of the phosphate produced industrially is used as a component of fertilizers since phosphorous is a necessary nutrient for plant life. Excess phosphate loss from land surfaces is a significant environmental challenge and can pollute waterways.

Why Test for Phosphate in Water?

Phosphate is a key analyte for certain wastewater treatment plants. Municipal wastewater facilities that employ biological nutrient removal (BNR) and enhanced nutrient removal (ENR) systems must measure phosphate as a requirement for their discharge permits.

In environmental monitoring, phosphate levels are monitored to gauge the health of aquatic ecosystems. High levels of phosphate can spur algae blooms and eutrophication. Regular phosphate testing can help identify these conditions and pinpoint potential pollution sources, such as fertilizer run-off.

In industrial water treatment, phosphate is used as a conditioner and corrosion inhibitor in boiler and cooling systems. Phosphate testing ensures systems are protected against corrosion and that the chemical is not being wasted.

About Our Phosphate & Orthophosphate Water Test Kits

CHEMetrics phosphate test kits measure ortho (reactive) phosphate.

CHEMetrics offers phosphate test kits using two different methods: Stannous Chloride and Vanadomolybdophosphoric Acid. Visual and instrumental phosphate test kit formats that span low and high measurement ranges are offered. Test results for visual test kits use color comparators for analysis while instrumental kits rely on CHEMetrics direct-readout photometers or spectrophotometers capable of accepting a 13-mm diameter round cell.

If you are testing high concentrations of phosphate, dilution may be used to extend the range of our test kit. You can find more information on our Sample Dilution Instructions.

Click on a catalog number in the tables below for more information or to purchase a phosphate test kit.

Visual Kits

Range MDL Method Kit Catalog No. Refill Catalog No.
0-1 & 1-10 ppm 0.05 ppm Stannous Chloride K-8510 R-8510
2-30 ppm 2 ppm Vanadomolybdophosphoric Acid K-8530 R-8515
0-120 ppm 5 ppm Vanadomolybdophosphoric Acid K-8515 R-8515
0-30 & 30-300 ppm 5 ppm Stannous Chloride K-8510D R-8510D

Instrumental Kits

Range Method Kit Catalog No.
V-2000: 0-8.00 ppm / V-3000 & Spec: 0-5.00 ppm Stannous Chloride K-8513
0-80.0 ppm Vanadomolybdophosphoric Acid K-8503

Phosphate Testing Methods

The Vanadomolybdophosphoric Acid Method

References: ASTM D 515-82, Phosphorous in Water, Test Method C. APHA Standard Methods, 23rd ed., Method 4500-P C-2005.
In phosphate water test kits employing the vanadomolybdophosphoric acid method, phosphate reacts with ammonium molybdate under acid conditions and in the presence of vanadium to form a yellow-colored product. Results are expressed as ppm (mg/L) PO4.
The Stannous Chloride Method

References: APHA Standard Methods, 23rd ed., Method 4500-P D-2005. Phosphate test kits employing this chemistry utilize a stannous chloride reduction.
 Phosphate reacts with ammonium molybdate and is then reduced by stannous chloride to form a blue complex. Results are expressed as ppm (mg/L) PO4.