120 NTERNATIONAL STANDARD ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXKAYHAPOAHA OPTAHI3ALIMA HIO CTAHIAPTH3ALIHM.ORGANISATION INTERNATIONALE DE NORMALISATION Plastics -- Phenol-formaldehyde mouldings - Determination of free ammonia and ammonium compounds -- Colorimetric comparison method Plastiques - Pieces moulees a base de phenoplastes - Dosage de I'ammoniac libre et des composés ammoniacaux -- Methode par comparaison colorimetrique First edition -- 1977-10-01 120-1977 (E) UDC 678.632 : (546.171.1 + 547.298.1) : 543.8 Ref. No. 1SO 120-1977 (E) Descriptors : plastics, phenol formaldehyde resins, mouldings, chemical analysis, determination of content, ammonia, colorimetric analysis. comparison analysis. d without license from IHS Not for Resale Price based .on 2 pages FOREWORD Iso (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing International 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. I nternational Standard ISO 120 was developed by Technical Committee ISO/TC 61, Plastics, and was circulated to the member bodies in October 1975. It has been approved by the member bodies of the following countries : Australia Iran South Africa, Rep. of Austria Israel Spain Belgium Italy Sweden Brazil Japan Switzerland Czechoslovakia Mexico Turkey Finland Netherlands United Kingdom France New Zealand U.S.A. Germany Peru U.S.S.R. Hungary Poland Yugoslavia India Romania No member body expressed disapproval of the document. This International Standard cancels and replaces ISO Recommendation R 120-1959, of which it constitutes a technical revision. @ International Organization for Standardization,1977 Printed in Switzerland without license from IHS Not for Resale ISO 120-1977 (E) INTERNATIONAL STANDARD Plastics --- Phenol-formaldehyde mouldings -- Determination of free ammonia and ammonium compounds -- Colorimetric comparison method 1 SCOPE AND FIELD OF APPLICATION 5 APPARATUS This International Standard specifies a colorimetric Ordinary laboratory apparatus, and comparison method for the semi-quantitative determination of the amount of 'ammonia in phenol-formaldehyde 5.1 Means for reducing the mouldings to a powder. mouldings. 5.2 Sieve, with nominal apertures of 250 μm, conform- NOTE -- This International Standard does not provide an absolute ing to Iso 565. measure of the ammonia present. The amount of ammonia in a moulded article is of 5.3 Balance, accurate to 0,01 g. importance when corrosion of metal inserts or contami- nation of foodstuffs in contact with the article has to be 5.4 Glass-stoppered flask, 250 ml capacity. considered. 5.5 Distillation apparatus, comprising a flask of 250 ml 2 REFERENCES capacity, splash head and a condenser. IsO 565, Test sieves -- Woven metal wire cloth and 5.6 Filter funnel, with hardened medium speed filter perforated plate -- Nominal sizes of apertures. paper. ISO 648, Laboratory glassware - One-mark pipettes.1) 5.7 Pipettes, capacities 2 and 10 ml, complying with the requirements of IS0 648. 3 PRINCIPLE 5.8 Nessler cylinders, 50 ml capacity. Hot aqueous extraction of free ammonia from a powdered test portion. Distillation of the aqueous extract in the presence of potassium permanganate and sodium hydroxide 6 PREPARATION OF TEST SAMPLE solution. Coloration of the distillate by reaction with Nessier reagent and. comparison of the colour with that Reduce a fully representative sample of the mouldings to obtained in each of a series of standard