microtest® Test Kit Specifications

microtest Phosphate-P MB+ (HS)

Colorimetric Test for

Phosphorus (Phosphate)

0.0 – 0.4 mg/L P

Product Code652400
ContentsReagent A, 15 mL
Reagent B, 2 g
Measuring spoon
Test tube, 5 mL (2x)
Colour Comparator
Instructions for Use
Analytical MethodMolybdenum Blue (ascorbic acid reduction): At a pH of ca. 1, ammonium molybdate reacts with phosphate forming colourless molybdophosphoric acid. Upon reduction with ascorbic acid it turns into the blue compound phosphoromolybdenum blue. The intensity of the colour is related to the phosphate concentration.
Number of Tests70
InterferencesWater constituents at concentrations commonly found in natural waters will not cause interferences. Various heavy metals (e.g. Nb, Ta, Sn, W, Ti, Zr, Bi) can cause serious interferences. Seawater and waters high in salinity will not interfere.
Measuring RangeThe standard measuring range is 0 – 0.4 mg/L phosphate-phosphorus. The colour comparator has 5 colour fields: 0–0.05–0.1–0.2–0.4 mg/L. For higher phosphorus concentrations, the sample has to be diluted. A 1:5 sample dilution can be carried out easily, thus extending the measuring range to 2 mg/L.
Shelf Life2 years
ApplicationsDetermination and monitoring of phosphorus levels in natural waters including brackish water and seawater (environmental monitoring).