Concentration β (NO₃⁻): 990 - 1010 mg/l
Determination method: Alkalimetric titration.
The content of this solution was determined with sodium hydroxid standard solution 0.1 mol/l .The sodium hydroxide standard solution 0.1 mol/l is adjusted by hydrochloric acid standard solution 0.1 mol/L.The hydrochloric acid standard solution is standardized and traceable to volumetric standard tris(hydroxymethyl)aminomethane (article number 1.02408). The expanded measurement uncertainty is ± 1 % (k=2 coverage factor for 95% coverage probability). The certified value is traceable to primary standard NIST SRM 723 (NIST: National Institute of Standards and Technology, USA) by means of volumetric standard tris(hydroxymethyl)aminomethane, measured in the accredited calibration laboratory of Merck KGaA, Darmstadt, Germany in accordance to DIN EN ISO/IEC 17025.