Simultaneous Determination of Total Nitrogen and Total Phosphorus in Sewage Water by Flow Injection Analysis after Continuous Flow Sample Degradation Using Heating Aluminum Block

Simultaneous determination of total nitrogen (T-N) and total phosphorus (T-P) in sewage water by flow injection analysis (FIA) have been developed. This analytical method provides high linearity of the calibration curve as well as repeatability and reproducibility. The correlation coefficients of the calibration curve were estimated to be from 0.9989 to 0.9999 for the T-N in the concentration range from 0.2 mg L−1 to 20 mg L−1, and for the T-P in the concentration range from 0.02 mg L−1 to 2 mg L−1. The detection limit calculated on 3σ were 0.186 mg L−1 for T-N, and 0.003 mg L−1 for T-P. This flow injection analysis could be successfully applied to the determination of T-N and T-P in the inlet water and outlet water of sewage water.