Overview
EN ISO 17380:2013 (ISO 17380:2013) specifies a laboratory method for the photometric determination of total cyanide and easily-liberatable cyanide in soil using automated distillation combined with continuous‑flow analysis (CFA). Published by CEN/ISO, the standard applies to all soil types with cyanide concentrations above 1 mg/kg (dry matter) and is intended for routine, high‑throughput analysis where reliability and reproducibility are required. The document includes safety notes (cyanide solutions are highly toxic) and guidance on sample pretreatment, reagents, apparatus and calculations.
Key topics and technical requirements
- Principle: Soil is extracted with 2.5 mol/L NaOH (16 h), diluted (100×) and analyzed by an automated distillation/CFA manifold with photometric detection.
- Determinations: Provides procedures for both total cyanide (includes complex cyanide after UV decomposition) and easily‑liberatable cyanide (weakly bound species measurable under the method conditions).
- UV decomposition: Complex cyanides are broken down in a continuously flowing stream using UV‑B irradiation and a borosilicate decomposition coil; buffer initial pH ~3.8 is used.
- Analytical range & interferences: Applicable for soil cyanide contents >1 mg/kg; sulfide concentrations >40 mg/kg (dry matter) interfere and may require sample dilution. Organic cyanides (e.g., acetonitrile) are not determined.
- Quality control: Calibration graphs, system checks, cleaning/maintenance of CFA apparatus, precision and recovery data, and reporting requirements are specified.
- Safety: Emphasizes toxicology and safe disposal of cyanide-containing solutions.
Applications and practical value
- Environmental monitoring of contaminated sites, brownfield assessment and soil quality surveys.
- Mining and mineral processing: monitoring cyanide in tailings and soils near gold or base‑metal operations.
- Remediation verification: tracking reductions in total and easily‑liberatable cyanide during treatment.
- Waste management and regulatory compliance: supporting permits and environmental risk assessments.
- High‑throughput analytical labs benefit from automation (CFA + automated distillation) for large sample series with consistent photometric results.
Who should use this standard
- Soil testing laboratories and environmental analytical service providers
- Environmental consultants, remediation contractors and mining environmental teams
- Regulatory agencies setting or enforcing soil quality limits
- Research groups studying cyanide behavior and speciation in soils
Related standards
EN ISO 17380:2013 provides a validated, automated workflow for accurate determination of cyanide species in soils, enabling reliable decision‑making in monitoring, remediation and regulatory contexts.