The orthophosphate level in mg/L (or ppm) is determined by a colorimetric
method. Ammonium molybdate and potassium antimonyl tartrate react in acid
medium with orthophosphate to form a phosphomolybdate complex that is
reduced to intensely coloured molybdenum blue by ascorbic acid. The colour
intensity of the solution determines the phosphate concentration. Phosphates
can be classified as ortho, condensed or organically bound. As with existing
test kits on the market, the HANNA Phosphate Test Kit will only determine ortho
phosphate levels. The test kit is supplied with the following;
20 ml plastic beaker, colour comparison cube and 50 packets
phosphate reagent.