ISO 20950-1:2018

Water quality — Determination of available weak and dissociable (WAD) cyanide — Part 1: Method using ligand exchange, flow injection analysis (FIA), gas-diffusion and amperometric detection

This document specifies operationally defined methods for the determination of available WAD cyanide in various types of water such as drinking, ground, and surface, waters, and metallurgical processing tailings reclaim, heap leach barren, mill slurry tailings and leaching solutions, with cyanide concentrations from 5 µg/l to 2 000 mg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by using a different injection volume, thicker membrane, detector response, etc. NOTE ISO 2080:2008, 3.105, defines free cyanide. The concentration of available WAD cyanide includes free cyanide and some of the metals complexed in solution as determined by a specified analytical method but not all of the metal complexes present in total cyanide (3,191). In this method, six suitable mass concentration ranges from 5 µg/l to 50 µg/l, from 50 µg/l to 500 µg/l, from 0,5 mg/l to 5 mg/l, from 5 mg/l to 50 mg/l, from 50 mg/l to 500 mg/l and from 500 mg/l to 2 000 mg/l are described.

Qualité de l'eau — Détermination du cyanure à acide faible dissociable (WAD) disponible — Partie 1: Méthode par échange de ligand, analyse par injection en flux (FIA), diffusion gazeuse et détection ampérométrique

General Information

• Status: Published
• Publication Date: 16-May-2018
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: ISO/TC 147/SC 2 - Physical, chemical and biochemical methods
• Drafting Committee: ISO/TC 147/SC 2/WG 66 - Cyanide
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 20-Mar-2024

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20950-1
First edition
2018-05
Water quality — Determination of
available weak and dissociable (WAD)
cyanide —
Part 1:
Method using ligand exchange, flow
injection analysis (FIA), gas-diffusion
and amperometric detection
Qualité de l'eau — Détermination du cyanure à acide faible
dissociable (WAD) disponible —
Partie 1: Méthode par échange de ligand, analyse par injection en flux
(FIA), diffusion gazeuse et détection ampérométrique
Reference number
ISO 20950-1:2018(E)
©
ISO 2018

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ISO 20950-1:2018(E)

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ii © ISO 2018 – All rights reserved

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ISO 20950-1:2018(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Interferences . 2
4.1 Interferences by oxidizing agents . 2
4.2 Interferences by sulfide . 2
5 Principle . 2
6 Reagents . 3
7 Apparatus . 7
8 Sampling and sample preparation . 7
8.1 General . 7
8.2 Oxidizing agents . 7
8.3 Sulfide removal . 8
8.4 Preservation . 8
9 Procedure.
...