Overview
EN ISO 14403-2:2012 - Water quality - Determination of total cyanide and free cyanide using flow analysis (Part 2: continuous flow analysis, CFA) - specifies a validated, automated continuous flow analysis (CFA) method for measuring cyanide in water. The standard applies to a wide range of waters (ground, drinking, surface, leachate, waste and, with adaptation, seawater) and covers typical cyanide concentrations from 2 µg/L to 500 µg/L, with the method example describing a suitable mass concentration range of 10 µg/L to 100 µg/L. It is an EU-endorsed ISO standard published by CEN/ISO and intended for routine, high-throughput laboratory analysis.
Key topics and technical requirements
- Analytes defined: distinguishes free cyanide (cyanide ion and weak metal–cyanide complexes liberating HCN at pH 3.8) and total cyanide (includes stronger metal–cyanide complexes except certain noble-metal complexes).
- Scope and detection range: typical working range 2–500 µg/L; example method range 10–100 µg/L. Range can be extended by sample dilution or changing flow-cell pathlength.
- Principle: automated introduction of sample into a flow manifold where cyanide is converted and detected downstream by flow detectors. This part focuses on CFA (continuous flow) rather than flow injection (FIA).
- Interferences & sample treatment: covers oxidizing agents (chlorine - treat with sodium thiosulfate and ascorbic acid), sulfide (remove with lead carbonate/lead precipitation and filtration), sulfite, nitrite, carbonyl compounds (ethylenediamine or silver nitrate where applicable). Use of KI‑starch paper, lead‑acetate paper and specific reagent additions are described to verify and mitigate interferences.
- Method elements: reagents, apparatus, sampling and preparation, flow-system setup, blank checks, calibration, sample measurement, calculation and reporting. Annexes include example flow systems, preparation of calibration solutions, an amperometric/gas-diffusion example (Annex C), and performance data.
Applications and users
- Environmental and public‑health laboratories performing cyanide monitoring in drinking, surface, groundwater and wastewater.
- Industrial process and effluent monitoring (mining, chemical manufacturing, metal finishing) where automated, high‑throughput cyanide analysis is required.
- Regulatory agencies and accredited testing labs following ISO/CEN standards for compliance reporting and method validation.
- Research groups studying cyanide fate and treatment effectiveness.
Related standards
Keywords: EN ISO 14403-2:2012, cyanide determination, continuous flow analysis, CFA, water quality, total cyanide, free cyanide, flow analysis, environmental monitoring.
