DETERMINATION OF PHOSPHORUS IN PHOSPHATE FERTILIZER BY ION CHROMATOGRAPHY

Ion chromatography was applied to the determination of phosphate in phosphate fertilizer.The fertilizer sample was digested with an appropriate amount of HNO3-HCl mixture to convert phosphorus of different species into soluble HPO2-4,and the total amount of phosphorus determined by IC using conductivity detector with chemical suppressor.Linear relationship between the peak area and the concentration of phosphate (expressed as P2O5) was obtained in the range of 1-50 mg·L-1.Satisfactory results,which were in consistency with those found by the chemical method,were obtained in the analysis of some fertilizer samples,and recoveries tested by the standard addition method were in the range of 93.0%-97.8%.