Determination of Hydrocyanic Acid and Free Cyanide in Aqueous Solution

摘要

Microgram-per-liter concentrations of HCN in aqueous solutions were determined directly by two methods: bubbling compressed air through a solution to displace a small quantity of HCN, which was collected in a glass bead concentration column, or allowing some HCN to diffuse from an enclosed solution into dilute NaOH in a dish suspended above the solution. The separated and concentrated cyanide was determined colorimetrically. These procedures for determining HCN in various waters and wastewaters were accurate, precise, and not susceptible to common interfering substances.