1388/3 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAR OPFAHW3AMA NO CTAHAAPTW3ALWM?ORGANISATION INTERNATIONALEDE NORMALISATION ANsimiernrt Doc Sec Ethanol for industrial use -- Methods of test - Part 3 : Estimation of content of carbonyl compounds present in small amounts - Photometric method Ethanol ausage industriel--Methodes d'essai -Partie 3: Evaluation de la teneur en composes carbonylés présents en faible quantité-Methodephotométrique First edition -- 1981-12-15 ISU 1388/3-1981 (E) UDC 661.722 : 543.854.6 Ref.No. ISO 1388/3-1981 (E) Descriptors : industrial products, ethanois, tests, determination, carbonyl compounds, spectrophotometric analysis. Price based on 3 pages 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. InternationalStandardISO1388/3wasdevelopedbyTechnicalCommitteeISO/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 France Poland Austria Germany, F.R. Romania Belgium Hungary South Africa, Rep. of Brazil Italy Switzerland Bulgaria Korea, Rep. of Thailand China Netherlands United Kingdom Czechoslovakia Philippines USSR No member body expressed disapproval of the document. International Standards ISO 1388/1 to ISo 1388/12 cancel and replace ISO Recom- mendation R 1388-1970, of which they constitute a technical revision. InternationalOrganizationforStandardization,1981 Printed in Switzerland INTERNATIONALSTANDARD ISO1388/3-1981(E) Ethanol for industrial use Methods of test Part 3 : Estimation of content of carbonyl compounds present in small amounts - Photometric method Scope and field of application 3.3 Hydrochloric acid, approximately 1,19 g/ml, about 38% (m/m)solution. This part of ISo 1388 specifies a photometric method for estimation of the content of carbonyl compounds present in 3.4 Potassium hydroxide, 100 g/l solution in a 70 % (V/V) small amounts in ethanol for industrial use. solution of the ethanol (3.1). The method is applicable to products having carbonyl com- 3.5 Carbonyl compounds, standard solution correspond- poundscontents,expressedasacetaldehyde，between ing to 0,440 g of carbonyl compounds, expressed as 0,000 25 and 0,01 % (m/m). acetaldehyde, per litre. NOTE -- This method, which is used commercially, allows determina Weigh, to the nearest 0,000 1 g, 1,200 g of acetophenone, and tion of only those carbonyl compounds which react under the specified conditions. dissolve it in a little of the ethanol (3.1).Transfer quantitatively to a100ml one-markvolumetricflask,diluteto the mark with ethanol of the same quality and mix.Take 10,o ml of this solu- This document should be read in conjunction with ISo 1388/1 tion, transfer it to a 100 ml one-mark volumetric flask, dilute to (see the annex). the mark with the ethanol (3.1) and mix. 1mlof this standardsolution contains 440 μg of carbonyl com- pounds, expressed as acetaldehyde. 2Principle Reaction in acid medium of the carbonyl compounds in a test 4 Apparatus portion with 2,4-dinitrophenylhydrazine. Formation of the cor- responding 2,4-dinitrophenyihydrazones, which, after making Ordinary laboratory apparatus, and the solution alkaline, take on a red coloration. Photometric measurement of this red coloration at a 4.1 Water bath, capable of being controlled at 50 ± 2 'C. wavelength