1742 International Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAR OPFAHM3AUWA NO CTAHAAPTM3AUWW·ORGANISATION INTE RNATIONALE DE NORMALISATION Glucose syrups - Determination of dry matter - Vacuum oven method Sirops de glucose -- Determination de la matiere seche -- Methode par étuvage sous pression reduite First edition 1980-08-01 ISO 1742-1980 (E) UDC 664.162 : 543.81 Ref.No. ISO 1742-1980 (E) Descriptors : carbohydrates, glucose, tests, determination of content, dry matter, dehydration analysis, stoves (chemistry), low pressure tests. 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 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 so, 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 1742 was developed by Technical Committee ISO/TC 93 Starch (including derivatives and by-products), and was circulated to the member bodies in May 1979. Australia Libyan Arab Jamahiriya Spain Chile Netherlands United Kingdom Gerimany, F. R. Poland USA Israel Romania USSR Kenya South Africa, Rep. of Yugoslavia The membier body of the following country expressed disapproval of the document on technical grounds : France This International Standard cancels and replaces ISO Recommendation R 1742-1970, of which it constitutes a technical revision. International Organization for Standardization, 1980 Printed in Switzerland Coovriaht Intermational Oranization for Standardization ISO 1742-1980 (E) INTERNATIONALSTANDARD Glucose syrups s -- Determination of dry matter -- Vacuum oven method 1 Scope and field of application 4.4 Glass stirring rod, of length appropriate to the diameter of the dish. This International Standard specifies a vacuum oven method for the determination of the dry matter in glucose syrups, ir 4.5 Electricaliy heated vacuum oven, capable of being respective of their method of production. maintained at 70 ± 1 °C, equipped with a calibrated ther- The method is also applicable to dried glucose syrup, solid mometer and an absolute pressure gauge. glucose (starch sugar), glucose syrup containing fructose (in- cluding isoglucose as defined by the European Community1). The drying oven shall provide uniform heat distribution and shall maintain the reduced pressure for several hours after the vacuum pump is turned off. The oven shelves shall be so 2 Principle constructed and fitted as to ensure good heat transfer to the dishes. Drying of a test portion, diluted with water and mixed with kieselguhr to provide a large surface for drying, in a vacuum 4.6 Vacuum pump, suitable for reducing the pressure in the oven at 70 oC, at a pressure not exceeding 34 mbar*. oven to 34 mbar or less. 3 Reagent 4.7 Drying train, consisting of a drying column filled with dried silica gel; the column is connected in series to a gas The reagent shall be of recognized analytical quality. Distilled scrubber containing concentrated sulphuric acid, which is in water or water of at least equivalent purity shall be used turn connected to the air inlet of the drying oven. 3.1 Diatomaceous earth filter aid (Kieselguhr), prepared 4.8 Desiccator, containing an efficient desiccant. as follows. Wash a large quantity of kieselguhr several times with water acidified with hydrochloric acid [1 ml of concentrated acid 5 Procedure (220 = 1,19 g/ml) per litre of water) by filtration on a Buchner funnel until the washings turn litmus paper red. Repeat the 5.1 Preparation of the test sample