Cyanide (free) Test Kits

Visual Kits

Range MDL Method Kit Catalog No. Refill Catalog No.
0-0.1 & 0.1-1 ppm 0.005 ppm Isonicotinic-Barbituric Acid K-3810 R-3810

Instrumental Kits

Range Method Kit Catalog No.
0-0.400 ppm Isonicotinic-Barbituric Acid K-3803

Method

 

Cyanide is used in many chemical and refining processes. It is found in effluent from electroplating and metal cleaning operations, coke ovens, steel manufacturing facilities, and gas scrubbers. Although cyanide can be safely removed by alkaline chlorination, its acute toxicity to aquatic life necessitates routine monitoring of effluents. The Maximum Contaminant Level for free cyanide in drinking water is 0.2 mg/L.

 

CHEMetrics' cyanide test kits are applicable to the monitoring of effluents and surface water supplies. It is recommended, however, that the sample be distilled and hydrogen sulfide be removed prior to analysis.

 

The Isonicotinic-Barbituric Acid Method

 

Reference: S. Nagashima, Spectrophotometric Determination of Cyanide with Isonicotinic Acid and Barbituric Acid, International Journal of Environ. Anal. Chem., 1981, Vol. 10, pp. 99-106.

 

In the Cyanide CHEMets® and Vacu-vials® Kit, chlorine is added to a sample that has been buffered to pH 6. The resulting cyanogen chloride reacts with isonicotinic and barbituric acids to form a blue color. Results are expressed as ppm (mg/L) CN.

 

This chemistry provides two advantages over the more commonly used pyridine methods: (1) The shelf life of the reagent is extended, and (2) the analyst is not exposed to noxious and hazardous fumes from the pyridine reagent.