6703/2 International Standard (ISO INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION-MEAYHAPOAHAR OPTAHW3AUMR NO CTAHAAPTW3AUWW+ORGANISATION INTE RNATIONALE DE NORMALISATIUN Water quality - Determination of cyanide Part 2: Determination of easily liberatable cyanide Qualite de I'eau--Dosaye des cyanures-Partie 2:Dosage des cyanures aisement liberables First edition -1984-09-01 ISO 6703/2-1984 (E) UDC 543.2:546.267 Ref.No. 1SO 6703/2-1984 (E) Descriptors :water, quality,tests, determination, cyanides, water pollution. Price bascd on 11 pages Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standardsbodies (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 International Standard ISO6703/2 was prepared by Technical Committee ISO/TC 147,Water quality. @International Organizationfor Standardization,1984 Printed in Switzerland i= Contents Page oIntroduction Scope and field of application Definition 2 2 Section one: Libcration and absorption of hydrogen cyanide 3Principle 3 4Reagents 3 5Apparatus 3 Sampling and samples 5 7 Procedure. 5 Section two:Determination of cyanide ions Photometric method with pyridine/barbituric acid Applicability 6 Principle 9 6 10 Reagents 6 11 Apparatus 12 Procedure 6 13 Expressionofresults Precision 14 15 Test report . Section three: Determination of cyanide ions - Titrimetric method using the Tyndall cffect 16Applicability. 8 17 Principle and reactions 8 18 Reagents 8 19 Apparatus 8 20 Procedure 6 21 Expressionof resul 9 22 Precision. 9 23 Test report 6 ili