PROCEDURE FOR DETERMINING NITROGEN CONTENT IN NPK CHEMICAL FERTILIZERS USING THE RAMAN DISPERSION METHOD

Abstract

The invention relates to a procedure for determining the nitrogen content in NPK fertilizers by Raman scattering. The procedure includes: establishing the positions of characteristic Raman peaks of different nitrogen forms; preparing 1 g samples, consisting of NPK fertilizer and varying amounts of a solid nitrogen-containing standard, grinding, mixing, pelletizing, and drying; recording the Raman spectrum of the sample; comparing the obtained Raman peaks with the standard peak to determine the nitrogen form; determining the relative intensity of the Raman peak, establishing a linear calibration curve between the amount of added standard and the peak intensity; and determining the nitrogen content from the intersection of the calibration curve with the x-axis. The procedure is non-destructive, fast, environmentally friendly, highly accurate, and allows for the quantification of total nitrogen as well as individual nitrogen forms.

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