ISO 1388/2 International Standard INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEKAYHAPOAHAR OPrAHM3AMA HO CTAHAAPTW3AUMU-ORGANISATION INTE RNATIONALE DE NORMALISATiON Ethanol for industrial use --- Methods of test Part 2 : Detection of alkalinity or determination of acidity to phenolphthalein Ethanol a usage industriel -- Methodes d'essai -- Partie 2 : Detection de I'alcalinite ou determination de I'acidité a la phénolphtaleine First edition -- 1981-11-01 NuV 19 1981 ISO 1388/2-1981 (E) UDC 661.722 : 543.241 Ref. No. 1SO 1388/2-1981 (E) Descriptors : industrial products, ethanols, tests, determination, alkalinity, acidity, phenolphthalein. Price based on 2 pages Copyright International Organization for Standardization e from IHS 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 the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. InternationalStandard ISO 1388/2wasdeveloped byTechnicat Committee ISO/TC47, 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 No member body expressed disapproval of the document. This International Standard has also been approved by the International Union of Pure and Applied Chemistry (IUPAC). International Standards ISO 1388/1 to ISO 1388/12 cancel and replace iSO Recom- International Organization for Standardization, 1981 Printed in Switzerland Copyright International Organization for Standardization e from IHS Not for Resale 1388/2-1981 (E) INTERNATIONAL STANDARD Ethanol for industrial use - Methods of test - Part 2 : Detection of alkalinity or determination of acidity to phenolphthalein Scope and field of application 4.2 Burette, of capacity 10 ml, graduated in 0,02 ml. This part of so 1388 specifies a method for the detection of Procedure alkalinity and, if appropriate, the subsequent determination of acidity of ethanol for industrial use. 5.1 Test portion The method is applicable to products having acidities, ex pressed as acetic acid (CHgCOOH), greater than or equal to Take 100 ± 0,1 ml of the laboratory sample. 0,000 8 % (m/ m). This document should be read in conjunction with ISo 1388/1 5.2 Determination (see the annex). Place 100 ml of the water (3.1) in the conical flask (4.1); add 0,5 ml of the phenolphthalein solution (3.3) and, if necessary, 2 Principle restore the pale pink coloration by the addition of a few drops of the sodium hydroxide solution (3.2). Add the test portion Dilution of a test portion with carbon dioxide-free water. (5.1) and a further 0,5 ml of the phenolphthalein solution (3.3) Checking whether the test solution is alkaline or acid to and note whether the solution is alkaline; if acid, titrate the test phenolphthalein, and, if appropriate, determination of the solution with the sodium hydroxide solution (3.2), stoppering acidity by titration with standard volumetric sodium hydroxide the flask and swirling its contents after each addition, until a solution. pink coloration, persisting for about 15 s, is obtained. Shake the contents of the flask, with the stopper in position, after each addition of sodium hydroxide solution. 3 Reagents During the analysis, use only reagen