A simple method for eliminating the interference of CH_3COONa in NO_3~--N determination by UV spectrophotometry method

摘要

In order to solve the interference of CH_3COONa on measuring nitrate nitrogen (NO_3-N) concentration by ultra-violet (UV) spectrophotometric method, a series of tests were done. The solution with different concentrations of CH_3COONa was added respectively to a set of standard solutions, which the concentrations of NO_3 -N were already known, and the interference degrees of CH_3COONa on the measurement of NO_3 by UV spectrophotometric method were examined. The results indicated that the interference degrees of CH_3COONa on the measurement of NO_3~-N concentrations were proportional to the concentrations of CH_3COONa in the standard solutions. Based on the tests, a set of correction curves was established, and the accurate NO_3 -N concentrations can be determined by the correction curves conveniently and quickly.