An ammonium standard solution is a chemical solution of precisely known ammonium concentration, used for calibrating instruments and performing quality control in laboratory analysis. These solutions are commercially available in various concentrations (e.g., 1 ppm, 10 mg/L, 50 mg/L) traceable to sources like the NIST, or they can be prepared from a concentrated source like ammonium chloride or ammonium nitrate by serial dilution.







