4321 NTERNATIONAL STANDARD Tso NTERNATIONAL ORGANIZATION FOR STANDARDIZATION·MEKYHAPOHA OPTAHW3AIIMH HO CTAHIAPTH3ALIWM.ORGANISATION INTERNATIONALE DE NORMALISATION Washing powders -- Determination of active oxygen content - Titrimetric method Poudres a laver - Dosage de I'oxygene actif - Methode titrimétrique First edition - 1977-09-01 AUG 2 6 1977 ANsl Iniernat Doc Sect ISO 4321-1977 (E) UDC 661.185 : 543 Ref. No. ISO 4321-1977 (E) Descriptors : surfactants, pulverulent products, washing powders, chemical analysis, determination of content, oxy gen, volumetric analysis. Price based on 2 pages Copyright International Organization for Standardization 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 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. International Standard ISO 4321 was developed by Technical Committee Iso/Tc 91, Surface active agents, and was circulated to the member bodies in August 1975. It has been approved by the member bodies of the following countries : Australia Iran Switzerland Austria Italy Thailand Belgium Japan Turkey United Kingdom Canada Netherlands U.S.A. Egypt, Arab Rep. of New Zealand Poland France U.S.S.R. Germany Yugoslavia Romania Hungary South Africa, Rep. of India Spain No member body expressed disapproval of the document. @ International Organization for Standardization, 1977 Printed in Switzerland Copyright International Organization for Standardization Not for Resale ISO 4321-1977 (E) INTERNATIONAL STANDARD Washing powders -- Determination of active oxygen content Titrimetric method 3 If aluminium sulphate is added, a preferential reaction with the O INTRODUCTION condensed phosphates may be obtained, and the formation of a Because of the specificity of washing powders and the complex with the manganese ions, which may occur in certain cases and which may lead to an end-point that is not sharp, may be relative stability of peroxyhydrates, the dissolution of avoided. washing powders is likely to be incomplete and may result in a loss of oxygen; these disadvantages have been avoided method of dissolution 5 REAGENTS adoption particular by of a appropriate to the determination of active oxygen content. During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 1 SCOPE This International Standard specifies a method for the 5.1 Aluminium sulphate, octadecahydrate determination of the active oxygen content of commercial [Al2(SO4)3.18H2O]. washing powders. 5.2 Suiphuric acid, solution containing bismuth and manganese. 2 FIELD OF APPLICATION Dissolve bismuth nitrate 2 g pentahydrate This method may be used for determining peroxyhydrates, [Bi(NO3'3.5H,O] and 4 g of manganese sulphate mono- for example sodium perborate; it should not be used for hydrate (MnsO4.H2O) [or an equivalent quantity of tetra washing powders which contain, in addition to peroxy- pentahydrate (MnSO4.4H,0 or MnS0,.5H,0)1 in hydrates, products which react with acid permanganates 1 000 mi of a 5 N sulphuric acid solution. under the analytical conditions. 5.3 (lf necessary) Sulphuric acid, solution containing The method may be used in the presence of (ethylene- dinitrilo)tetraacetic acid (EDTA) or other chelating agents aluminium, bismuth and manganese. of the same type, provided that the concentration of these Dissolve 50g of the aluminium sulphate (5.1), 5g of products does