Development of total nitrogen and total phosphor on-line monitor using flow injection analysis

摘要

We have developed total nitrogen and total phosphorus on-line monitor using capillary heating and pressurizing with Flow Injection Analysis (FIA). Total nitrogen and total phosphorus are measured with following method. First, the sample is injected into flow of carrier solution. And flow of Potassium peroxodisulfate/Sodium hydride solution is added to the carrier flow. And the flow introduced to capillary heating coil. The nitrogen compounds in the sample are changed into nitric ion through the coil. The nitric ion is determined by UV absorption detector. Continuously the flow after UV absorption detector is added by the flow of Potassium peroxodisulfate/Sulfuric acid solution, and introduced to the other capillary heating coil again. Phosphorus compounds in the sample are changed into phosphoric ion in the coil. The phosphoric ion is colored by molybdenum blue method, and it is determined by V'S absorption detector. As the combined method leads to short analysis time, wide range analysis without sample dilution. And application of sewage plant was performed.