Analytical Reference Glossary
Plain-language definitions for the analytical chemistry and laboratory science terms used across our products and articles.
Cyanide Analysis
Cyanide Distillation
A sample preparation step in total cyanide analysis where strong acid, heat, and UV irradiation are used to break down all cyanide-containing species — including stable iron-cyanide complexes — and collect the liberated HCN gas for measurement.
Free Cyanide
The sum of the cyanide ion (CN⁻) and hydrogen cyanide (HCN) in solution. The most acutely toxic and biologically available form of cyanide, and a subset of WAD cyanide.
Total Cyanide
The comprehensive measure of all cyanide-containing species in a sample, including free cyanide, WAD-range metal complexes, and the stable iron-cyanide complexes that survive weak acid conditions.
WAD Cyanide
The fraction of cyanide in solution that dissociates under weak acid conditions (pH 4.5), releasing hydrogen cyanide gas. Includes free cyanide and labile metal-cyanide complexes, but excludes stable iron-cyanide species.
Flow Analysis
Continuous Flow Analysis
The family of automated wet chemistry techniques in which sample and reagents are continuously pumped through tubing and a detector while moving. Includes both Segmented Flow Analysis (SFA) and Flow Injection Analysis (FIA).
Flow Injection Analysis
A continuous-flow technique in which a precisely timed sample plug is injected into a flowing reagent stream. No air segmentation is used; reproducible results depend on controlled dispersion and precise timing.
Segmented Flow Analysis
An automated continuous-flow technique in which air bubbles regularly segment the liquid stream, preventing carryover between samples and enabling high-throughput batch analysis.