International Standard (IsO) 1388/12 INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAA OPTAHM3ALMA NO CTAHAAPTW3ALMW-ORGANISATION INTERNATIONALE DE NORMALISATION Ethanol for industrial use -- Methods of test Part 12 : Determination of permanganate time Ethanol a usage industriel -- Methodes d'essai -- Partie 12 : Deétermination du temps de permanganate First edition -- 1981-12-01 SU T388/12-1981 (E) UDC 661.722 : 543.8 Ref.No.1SO1388/12-1981 (E) Descriptors : industrial products, ethanols, tests, determination, permanganates, time, potassium permanganate. Price based on 3 pages onal Organization for Standardizatic Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of developing Inter. national Standards is carried out through iso technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with iso, also take part in the work. Draft International Standards adopted by thetechnical committeesare circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. International Standard ISO 1388/12 was developed by Technical Committee ISO/TC 47, Chemistry, and was circulated to the member bodies in February 1980. it has been approved by the member bodies of the following countries : Australia Germany, F.R. Romania Austria Hungary South Africa, Rep. of Belgium India Switzerland Brazil Italy Thailand Bulgaria Korea, Rep. of United Kingdom China Netherlands USSR Czechoslovakia Philippines France Poland Nomemberbodyexpresseddisapprovalofthedocument This International Standard has also been approved by the Internationai Union of Pure and Applied Chemistry (IUPAC). International Standards ISO 1388/1 to ISO 1388/12 cancel and replace ISO Recom- mendationR1388-1970,of whichtheyconstituteatechnical revision. InternationalOrganizationforStandardization,1981 Printed in Switzerland Provided by IHS under license with ISO Noreproduction or networking pemited without license from IHS Not for Resale INTERNATIONALSTANDARD ISO1388/12-1981 (E) Ethanol for industrial use - Methods of test Part 12 : Determination of permanganate time Scope and field of application Prepare this solution on the day of use. Thispartof ISO1388specifiesamethodforthedetermination of the permanganate time of ethanol for industrial use. 5 Apparatus This document should be read in conjunction with ISo 1388/1 (see the annex). NOTE - Clean the glassware used so as to avoid any risk of con. tamination. Ordinary laboratory apparatus, and 2 Definition 5.1 Water bath, capable of being controlled at 15 ± 0,2 oC. permanganate time : The number of minutes required, after adding 2 ml of 0,2 g/l potassium permanganate solution to 5.2 Two matched cylinders, of capacity 100 ml, of 50 ml of the sample, for the colour to match that of a colour transparent and colourless glass, graduated at 50 ml and fitted standard. with ground glass stoppers. 5.3 Burette, of capacity 10 ml, graduated in 0,05 ml div- isions. 3Principle Addition to a test portion, under specified conditions, of potassium permanganate solution. Determination of the time taken for the colour of this test solution to match that of a 6 Procedure cobalt(ll) chloride and uranyl nitrate colour standard. 6.1 Test portion Carry out the test as soon as possible after receipt of the sam- ple. (instructions for the storage of the sample are specified in Reagents ISO1388/1.) During the analysis, unless otherwise specified, use only Rinse one of the cylinders (5.2), first with 15 to 20 ml of reagents of recognized analytical grade, and distilled water or hydrochloric acid, Q approximately 1,19 g/ml, about 38 % water of equivalent purity. (m/ m) solution, then six times with tap water, twic