Qualitative identification of nitrate nitrogen in compound fertilizers by infrared spectroscopy

摘要

In this study, NPK compound fertilizers containing nitrate nitrogen were tested by Fourier transform infrared spectroscopy (FTIR), and the relative contents of nitrate nitrogen and qualitative comparison were qualitatively identified. The raw materials of compound fertilizers: agricultural ammonium nitrate (AN), potassium nitrate (KNO3) and ammonium phosphate (NH4)(2)HPO4 were analyzed by infrared spectroscopy respectively. The results showed that the absorption peaks of nitrate (NO3-1) in solid agricultural fertilizers were 1384cm(-1), 825cm(-1). Furthermore, the NPK compound fertilizer with 4%, 5.5%, 6% and 9.5% nitrate nitrogen content were respectively tested by infrared spectroscopy. The results showed that with the increase of nitrate nitrogen content in the compound fertilizers, the relative intensity of the infrared absorption peaks of nitrate increased as well. Moreover, the relative intensity of the absorption peaks at 1384cm(-1) and 825cm(-1) are proportional to the content of nitrate in the nitro-compound fertilizer-containing ammonium nitrogen and nitrate nitrogen.