Hanna Instruments

Colorimetric testing is a method of determining the concentration of a chemical element or compound (organic or inorganic) in a solution with the aid of a colour reagent.

Our test kits measure the strength or weakness of a chemical presence according to the degree of colour saturation. Ie – if it is pale in colour, then the chemical concentration is low. If the colour is strong, then the chemical concentration is high. Simply add the reagent to the compound to be tested and match the colour gained against a colour chart included in the kit.

Phosphate test kit for irrigation water

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.

Phosphates are widely introduced into the environment from such sources as agricultural fertilisers, cleaning and laundering products, boiler water conditioners and drinking water treatment aids. At high levels, phosphates stimulate the growth of photosynthetic organisms which may contribute to eutrophication of lakes, rivers and ponds. This makes it important to monitor and control phosphate discharges into the environment.

The HI-3833 test kit is supplied with the following;
20 mL plastic beaker, colour comparison cube and 50 packets phosphate reagent.

Check out our Checker® HC Handheld Colorimeters – a highly-accurate and affordable way to test for chemicals using a gadget that sits perfectly in the palm of your hand and also fits nicely into your pocket.