Artsl inttrmct De sec OSI) 7108 International Standard INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEKAYHAPOHHAR OPTAHW3AUMR nO CTAHAAPTU3AWM-ORGANISATION INTE RNATIONALE DE NORMALISATION Ammonia solution for industrial use - Determination of ammonia content - Titrimetric method Ammoniaque a usage industriel -- Détermination du titre en ammoniac - Methode titrimetrique First edition - 1985-06-01 Ref. No. ISO 7108-1985 (E) UDC 661.5 : 543.24 : 543.272.35 SO 7108-1985 (E) Descriptors : industrial products, chemical compounds, volumetric analysis. Price based on 2 pages Copyright International Organization for Standardization H without license from IHS Notfor Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of Standards is normally carried out through Iso technical committees. Each 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 Councif. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7108 was prepared by Technical Committee ISO/TC 47, Chemistry. @ International Organization for Standardization, 1985 Printed in Switzerland Copyright InternationalOrganizationfor Standardization from IHS Notfor Resale ISO 7108-1985 (E) INTERNATIONAL STANDARD Ammonia solution for industrial use - Determination of ammonia content - Titrimetric method WARNING -- Carry out all the operations in a well-ventilated fume cupboard. Scope and field of application capillary end about 50 mm in length (a typical example is shown in the figure). This International Standard specifies a titrimetric method for the determination of the ammonia content of ammonia solution Dimensions in millimetres for industrial use. The method is applicable to solutions con- taining not more than 35 % (m/ m) of ammonia. 2 Principle Introduction of a test portion into a solution of boric acid and titration with a standard volumetric solution of sulfuric acid in the presence of methyl red as indicator. 60 3 Reagents During the analysis use only reagents of recognised analytical grade and only distilled water or water of equivalent purity. Figure Spherical glass ampoule 3.1 Boric acid, 20 g/l solution. 5 Procedure 3.2 Sulfuric acid, standard volumetric solution, 5.1 Test portion c(1/2 H2SO4) = 1 mol/1.1) Weigh the glass ampoule (4.1) to the nearest 0,000 1 g. Gently 3.3 Methyl red, 1 g/l ethanolic solution. heat the spherical part of the ampoule over a flame and dip the capillary end of the ampoule into the bottle containing the Dissolve 0,1 g of methyl red in 95 % (V/ V) ethanol and make laboratory sample. Ensure that the ampoule is filled to two- thirds of its capacity during cooling. up to 100 m! with the same ethanol. Withdraw the ampoule and dry the capillary tube carefully with filter paper. Seal the end of the capillary tube, without loss of 4 Apparatus glass, with an oxidizing flame. Allow the capillary tube to cool, wash it with water and wipe it with filter paper until completely Ordinary laboratory apparatus and dry. 4.1 Spherical ampoule, of thin glass, of suitable capacity Weigh the sealed ampoule to the nearest 0,000 1 g and and shape, for example, about 20 mm diameter, with one calculate, by difference, the mass of the test portion. 1) Hitherto described as "1 N sulfuric acid solution". Copyright International Organization for Standardization nse from IHS Not for Resale