6703/3 (TSO nternational Standard INTE RNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAA OPTAHW3AUWA O CTAHAAPTW3ALMWORGANISATION INTE RNATIONALE DE NORMALISATION Water quality - Determination of cyanide Part 3: Determination of cyanogen chloride Qualité de I'eau -- Dosage des cyanures - Partie 3: Dosage du chlorure de cyanogene First edition 1984-09-01 UDC 543.2 : 546.267 Ref. No. ISO 6703/3-1984 (E) Descriptors : water, quality, tests, determination, cyanides, water pollution. itted without license from IHS Not for Resale Price based on 6 pages Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Every member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with IsO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with IsO procedures requiring at least 75 % approval by the member bodies voting. International Standard 1SO6703/3 was prepared Technical Committee by ISo/Tc 147, Water quality. International Organization for Standardization, 1984 Printed in Switzerland Not for Resale INTERNATIONAL STANDARD ISO 6703/3-1984 (E) Water quality -- Determination of cyanide Part 3: Determination of cyanogen chloride Attention is drawn to the toxicity of cyanide and to the need to take extreme care when handling cyanides and their solu- tions. Carry out all operations in a fume cupboard. Avoid contact with the skin and eyes. When pipetting, always use a safety pipette (pipette by bulb). Detoxify samples and solutions containing cyanides or heavy metals in accordance with local official regulations. Other chemicals specified in this part of iso 6703 are also hazardous, for example pyridine Introduction. 0 The ions and compounds listed in the table, if present singly or in combination at concentrations above the specified limiting Cyanides may be present in water as hydrocyanic acid (prussic concentration, interfere with the method (the list is not ex- acid), as cyanide ions and as complex cyanides. They may be haustive). determined as total cyanide or as easily liberatable cyanide. If The presence of aldehydes, e.g. formaldehyde, may give lower cyanide compounds are chlorinated, cyanogen chloride (CICN) cyanide values because of the formation of cyanohydrin. is produced, and this compound has to be determined Table -- Interferences separately. This International Standard comprises four parts as follows: Limiting Interference concentration mg/l Part 1 : Determination of total cyanide 1 000 Sulfide ion Part 2: Determination of easily liberatable cyanide Polysulfide ion 300 Sulfide and polysuifide ion 1 000 Part 3: Determination of cyanogen chloride Sulfite ion 500 1 000 Thiosulfate ion Thiocyanate jon 1 000 Part 4: Determination of cyanide by diffusion at pH 61) 250 Chlorine (elemental) The methods described in parts 1, 2 and 3 are suitable for con- trolling the quality of water and.for the examination of Definition 2 municipal sewage and industrial effluents. They are appropriate to the technology available for the destruction of cyanides in For the purpose of this International Standard, the following treatment plants, and are based on the separation of liberated definition applies : hydrogen cyanide (or in the case of this part of IS0 6703, of cyanogen chloride) by stripping with a carrier gas. cyanogen chloride: The first reaction product when cyanide compounds are chlorinated. The method specified in part 4 is suitable for the determination of smaller amounts of cyanide, depending on