VISOCOLOR® HE Phosphate (DEV) • Colorimetric determination of phosphate • Ammonium molybdate reacts with phospat ions to form phosphomolybdic acid which is reduced to molybdenum blue. • The tests with the designation DEV use the same reagents as the German Standard Methods. • Larger amounts of oxidising compounds inhibit the formation of the blue colour complex and have to be destroyed prior to the test. • H2S interferes in concentrations above 2 mg/l, but can be expelled after acidification of the water sample. • Heavy metals in excess of 10 mg/l can slightly decrease the colour intensity, vanadium causes an increase in colour. • Silica interferes and causes falsely high results. • Arsenates react like phosphates. • Citrate, oxalate, tartrate etc. reduce the sensitivity of the phosphate test. (Reaction principle analogous to APHA 4500-P E, EPA 365,2+3, DIN EN ISO 6878-D11) • Type: high sensitive test kit • Range: 0.0 · 0.01 · 0.02 · 0.03 · 0.05 · 0.07 · 0.10 · 0.15 · 0.20 · 0.25 mg/l P • Sufficient for: 100 determinations • Shelf life at least: 24 months • Sea water suitability: yes • Detectable with PF-11: no • The phosphate content in a surface water has direct consequences for its ability to support the growth of certain organisms. • Since ever increasing quantities of phosphates are being fed through domestic waste waters into rivers and lakes, these waters have a tendency towards eutrophication. • Exact data about the phosphate content are important for boiler water and feed water. • Precise dosing of phosphates in these waters can inhibit formation of boiler scale. • Pyro-, meta- and polyphosphates are not determined with VISOCOLOR® test kits. • The determination of total phosphate requires a decomposition prior to the test.