Assay of ammonium chloride

The assay of ammonium chloride involves an aqueous acid-base titration based on neutralization, where ammonium chloride is treated with formaldehyde to release hydrochloric acid, which is then titrated with sodium hydroxide. The procedure includes dissolving a sample in water, adding formaldehyde and an indicator, and titrating until a color change occurs. This assay ensures the quality and consistency of ammonium chloride, which is used in pharmaceuticals, particularly in cough medicine. Factors such as instrument precision, sample handling, reagent quality, and environmental conditions can impact assay accuracy.