6703/3 International Standard (TSO INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION+MEXAYHAPOIHAR OPTAHW3AUWR NO CTAHIAPTW3AUMM+ORGANISATION INTE RNATIONALE DE NO RMALISATION Water quality - Determination of cyanide Part 3: Determination of cyanogen chloride Qualitede I'eau--Dosage des cyanures-Partie3:Dosagedu chloruredecyanogene First edition - 1984-09-01 ISO 6703/3-1984 (E) UDC 543.2: 546.267 Ref. No. ISO 6703/3-1984 (E) Descriptors: water, quality,tests, determination, cyanides,water pollution. 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 accordancc with ISo procedures requiring at least 75 % approval by the member bodies voting. ISO6703/3 wasprepared by Technical Committee International Standard ISO/TC 147, Water quality. International Organization forStandardization,1984 ( Printed in Switzerland ISO6703/3-1984(E) INTERNATIONAL STANDARD Water quality - Determination of cyanide - Part 3: Determination of cyanogen chloride Attention is drawn to the toxicity ofcyanidc andto the nced to takc cxtreme 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 officialregulations. Other chemicals specified in thispart of Iso 6703are also hazardous, for examplepyridine. Introduction 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.Thcy 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 separately. Table -- Interferences This International Standard comprises four parts as follows: Limiting Interference concentration Part 1: Determination of total cyanide mg/1 Sulfide ion 1 000 Part 2: Determination of easily liberatable cyanide Polysulfide ion 300 Sulfide and polysuifide ion 1 000 Sulfite ion 500 Part 3: Determination of cyanogen chloride Thiosulfate ion 1.000 Thiocyanate ion 1 000 Part 4: Determination of cyanide by diffusion at pH 61) Chlorine (elemental) 250 The methods described in parts 1, 2 and 3 are suitable for con- trolling the quality of water and.for the examination of 2 Definition 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 iSO 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 the concentra- Cyanogen chloride is a gas and is only slightly soluble in water, tions of copper and nickel. but is highly toxic eve