Probe test for cyanide in sewage - uses semipermeable membrane to collect ions for indicator reaction

摘要

The probe detects the presence of a cyanide in sewage by collecting the ions thorugh a semi-permeable cellulose membrane. This forms a tube contained in a probe which is placed in the sewage. Air contg. chloramine T is passed through the probe. The chloramine reacts with cyanide ions and removes them for analysis. The product is tested by reacting it with barbituric acid in pyridine and hydrochloric acid. The product turns red if cyano-chloride is present. This method can test for other substances by the use of different reagents.