Cyanide: total, weak acid dissociable and amenable to chlorination measurement context
Total cyanide, Standard Methods 4500-CN E: the sample is distilled from strong acid to release cyanide from most of its complexes, and the cyanide collected is measured by colorimetry (chloramine-T with a pyridine-barbituric acid reagent). Weak acid dissociable cyanide, Standard Methods 4500-CN I, uses a milder, weakly acidic distillation that releases free cyanide and the weaker metal complexes but not the strong iron cyanide complexes. Cyanide amenable to chlorination, Standard Methods 4500-CN G, is total cyanide measured on two portions, one of them chlorinated first; the difference is the cyanide that chlorination destroys. Reported as mg/L cyanide (CN).
Define where the property is measured
Specify field or laboratory measurement, units and the sample state needed for the project. A delivered sample may not preserve the source-time condition for a changing property.
Include the complete project requirement
Provide the matrix, target analytes, required method, fraction, units and reporting limits. Include the permit or monitoring instructions where results will support a regulatory submission. Naming this method does not establish blanket compliance eligibility.
Resolve collection before sampling
Use the bottle, preservation and delivery instructions assigned to the agreed scope. Identify each location and collection time, and document any deviation. The final analytical plan must fit the submitted material and its intended use.
Related testing & guidance
Technical & service references
Vanguard service detailsSource review: November 8, 2026. The agreed method and project scope govern the testing.