Sensitive and Robust Assay for Ammonia in Sodium Bicarbonate
Product News May 30, 2014
Thermo Fisher Scientific has developed a new ion chromatography (IC)-based method that overcomes typical challenges associated with quantification of low amounts of ammonia in the presence of a high concentration of sodium in sodium bicarbonate.
Application Note 1073: Determination of Ammonia in Sodium Bicarbonate demonstrates that this assay meets the analytical performance characteristics recommended by United States Pharmacopeia (USP) General Chapter <1225>, including precisions (retention time relative standard deviation [RSD] less than 0.1% and peak area RSD less than 2%), accuracy (average recovery 88-117%), limits of detection, and robustness.
A reliable assay for ammonia is needed because sodium bicarbonate is used in a wide variety of pharmaceutical and food products and elevated levels of ammonia in the blood stream can have adverse effects.
The current USP monograph for sodium bicarbonate describes an ammonia assay that exposes the analyst to a toxic mercury compound.
Use of a high-capacity cation-exchange column (Thermo Scientific™ Dionex™ IonPac™ CS16 column) enables the IC method to meet the USP’s detection limit criteria of 0.002% for ammonia in sodium bicarbonate.
In addition, automation features such as the electrolytically generated mobile phase and self-regenerating suppressor contribute to the robustness and sensitivity of this method.
Only water is used to generate the mobile phase and no hazardous chemicals are used in this IC assay for ammonia.