Determination of urea, phosphate, and potassium in agricultural runoff waters using electrochemical impedance spectroscopy.

Large-scale use of chemical fertilizers has resulted in the contamination of agricultural runoff waters by soil macronutrients NPK, whose detection is of significant interest. This work reports the determination of macronutrients in the form of urea (N), orthophosphate PO (P), and potassium K (K) in simulated agricultural runoff waters. Their solutions were prepared by extracting water-soluble constituents of soil.