Total phosphorus
Thread Content
Why is total phosphorus in circulating water measured as PO3?
It’s phosphate (PO43-), right? In fact, it is the organic phosphonic acids that are truly effective, while the levels of orthophosphate and phosphite are very low, and can sometimes be ignored. During routine testing, heating with sulfuric acid and a decomposing agent is generally used to convert organic phosphines and phosphites entirely into orthophosphoric acid; thereafter, by adding a quinomolybdic citrate solution, a quinoline phosphomolybdic acid precipitate is formed, allowing for the determination of the total phosphorus content. This is mainly for convenience; of course, if greater accuracy is desired, the content of organic phosphines can be obtained by subtracting the values of orthophosphates and phosphites from the aforementioned values after measuring their concentrations. This is the method for testing total phosphorus and organic phosphines in organic phosphonic acid scale inhibitors (such as HEDP, ATMP, etc.). I wonder if it is the same as the method used to detect total phosphorus in water?
You can also use P if you want; you just need to make the conversion.