What Is Cyanide?
Cyanide is a reactive carbon–nitrogen compound found in a variety of industrial processes. In water systems, cyanide typically appears as free cyanide, which includes both the cyanide ion (CN⁻) and hydrogen cyanide (HCN). These forms are the most biologically active and are therefore the most important to measure when assessing environmental and human health risks.
Cyanide is used or generated in several industries, including:
- Electroplating and metal finishing
- Steel and coke production
- Gas scrubbing operations
- Polymer and chemical manufacturing
Because cyanide readily complexes with metals, it is both industrially useful and environmentally hazardous. Total cyanide includes all inorganic cyanide species that can be converted to free cyanide under strong acidic conditions, while free cyanide represents the immediately toxic fraction.
Why Test for Free Cyanide?
Cyanide is acutely toxic to aquatic organisms and poses significant health risks to humans, making accurate monitoring essential.
- Regulatory compliance: Industrial and municipal facilities must routinely test effluent to ensure cyanide levels meet discharge permit requirements.
- Drinking water protection: The Maximum Contaminant Level (MCL) for free cyanide in drinking water is 0.2 mg/L.
- Environmental monitoring: Testing helps prevent contamination of rivers, lakes, and potential drinking water sources.
- Treatment verification: Cyanide can be destroyed through alkaline chlorination, and testing confirms treatment effectiveness.
Because cyanide can cause both immediate and long‑term harm, routine monitoring is essential for safety, compliance, and environmental stewardship.
Our Cyanide (Free) Test Kits
CHEMetrics provides free cyanide test kits designed for fast, accurate measurement in field and laboratory settings. These kits are suitable for monitoring wastewater, surface waters, and industrial effluents.
CHEMets® Visual Free Cyanide Test Kits
These colorimetric kits use the Isonicotinic–Barbituric Acid Method, a proven analytical technique for detecting free cyanide.
- Produces a blue‑purple color proportional to cyanide concentration
- Results compared against a calibrated color comparator
- Reported in ppm (mg/L) cyanide
- Ideal for field screening and routine monitoring programs
Sample pretreatment is recommended to remove hydrogen sulfide, which can interfere with the test.
Vacu‑vials® Instrumental Cyanide Test Kits
For applications requiring higher precision or digital documentation, CHEMetrics offers instrumental test kits using the same chemistry.
- Self‑filling 13‑mm ampoules compatible with most photometers and spectrophotometers
- Suitable for compliance reporting and laboratory analysis
- Provides enhanced accuracy and repeatability
For total cyanide analysis, sample distillation is required prior to testing.
Browse Our Kits
All CHEMetrics cyanide test kits, along with a full range of water‑quality testing supplies, are available through the AquaPhoenix Scientific eStore.