Orthophosphate ions dosage using spectrophotometry
Phosphorus is present in water in different forms: orthophosphates (H2PO4- / HPO42- / PO43- depending on the pH of the water) and polyphosphates. The determination of total phosphorus therefore requires polyphosphate mineralization.
We will be interested here only in the determination of orthophosphates soluble in water. These will be H2PO4- / HPO42- / PO43- depending on the pH of the water.