What is Cyanide?
Cyanide (CN–) is a carbon nitrogen compound used in many chemical and refining processes. It readily reacts with transition metals which makes it useful for industrial purposes but also makes it a toxic compound. Cyanide is often found in effluent from electroplating and metal cleaning operations, coke ovens, steel manufacturing facilities, gas scrubbers, and polymer production. Free cyanide is defined as the sum of molecular hydrogen cyanide (HCN) and cyanide ion (CN–). Total cyanide is the sum of all inorganic forms of cyanide that dissociate into free cyanide when refluxed under strongly acidic conditions.
Why Test for Cyanide?
Cyanide can be safely removed from water by alkaline chlorination. However, due to its acute toxicity to aquatic life, discharges from industrial and municipal wastewater facilities are regulated through permitting processes, necessitating routine effluent monitoring. Due to the potential for both short-term and long-term health effects to humans, the Maximum Contaminant Level for free cyanide in drinking water is 0.2 mg/L. It is common to monitor effluents and surface water supplies for cyanide to ensure that it is not entering natural waters or potential drinking water sources.
About Our Test Kits
CHEMetrics’ free cyanide water test kits are applicable for monitoring effluents and surface water supplies. Sample pretreatment to remove hydrogen sulfide is recommended. For total cyanide analysis, distillation of the sample is required.
CHEMetrics offers both visual and instrumental test kits employing the Isonicotinic-Barbituric Acid Method for the measurement of free cyanide in water.
The CHEMets® visual colorimetric test kit develops a blue-purple color in direct proportion to the free cyanide concentration. Measurements are made against a color comparator. Results are expressed as ppm (mg/L) cyanide.
Vacu-vials® instrumental cyanide testing requires the use of a CHEMetrics direct-readout photometer or spectrophotometer capable of accepting a 13-mm diameter round cell.
Click on a catalog number in the tables below for more information or to purchase a test kit.
|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|
|Range||Method||Kit Catalog No.|
|0-0.400 ppm||Isonicotinic-Barbituric Acid||K-3803|
The Isonicotinic-Barbituric Acid Method