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1、International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON.MEKfiYHAPOfiHAR OPTAHM3AUMfi n0 CTAHW TM3ALlkI*ORGANlSATlON INTERNATIONALE DE NORMALISATION Leather - Determination of nitrogen content and “hide substance” - Titrimetric method Cuir - Determination de la teneur en azo te et de la
2、 ccsubstance dermique) - Mthode titrime trique First edition - 1984-03-15 UDC 675 : 543.846 Ref. No. IS0 5397-1984 (E) Descriptors : leather, tanning, tests, determination of content, nitrogen, volumetric analysis. Price based on 3 pages Copyright International Organization for Standardization Provi
3、ded by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national stand
4、ards bodies (IS0 member bodies). The work of developing International Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been authorized has the right to be represented on that committee. International organization
5、s, 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 IS0 Council. International Standard IS0
6、5397 was developed by Technical Committee Leather, and was circulated to the member bodies in November 1980. ISO/TC 120, It has been approved by the member bodies of the following countries: Australia India Brazil Korea, Rep. of Canada Mexico Czechoslovakia New Zealand Egypt, Arab Rep. of Poland Hun
7、gary Portugal Romania South Africa, Rep. of Spain Turkey United Kingdom USSR The member body technical grounds of the following country expressed disapproval of the document on France This International Standard is based on Method IUC/lO of the International Union of Leather Technologists and Chemis
8、ts Societies. 0 International Organization for Standardization, 1984 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or netwo
9、rking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 5397-1984 (E) Leather - Determination of nitrogen content and “hide substance” - Titrimetric method 0 introduction The determination of “hide substance” from nitrogen content is based on the fact that, according to Schroder an
10、d Passler, the grease- and ash-free dry substance of the pelts of various animals has a somewhat different, but practically constant, nitrogen content for certain types of animal. 4 Principle Decomposition of a test portion by the Kjeldahl method. Distillation of the ammonia liberated, by one of the
11、 usual methods. Determination of the nitrogen content by titration of the ammonia with sulfuric or hydrochloric acid, using phenolphthalein as indicator. 5 Reagents 1 Scope and field of application This International Standard specifies a titrimetric method for the determination of the nitrogen conte
12、nt and of the “hide substance” of leather. The method is applicable to all types of leather in all types of tannage. NOTE - Other nitrogenous substances (e.g. certain fixatives, syn- thetic tannins, cationic fats and dyestuffs) falsify the value for the “hide substance”. If these materials are prese
13、nt, it is not possible to obtain an accurate result for the “hide substance”. During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 5.1 Fuming sulfuric acid, 7 % (m/m) of free SO 8.2 Blank test m is the mass, in grams, of the te
14、st portion (8.1). Carry out a blank test at the same time as the determination, following the same procedure and using the same reagents as used for the determination. Take as the result the mean of two determinations, provided that the requirement for repeatability (see 9.2) is satisfied, and expre
15、ss it to one decimal place. 8.3 Determination 9.1.2 The “hide substance” H, expressed as a percentage by mass, is given by the formula To the test portion (8.1) in the Kjeldahl flask, add 30 ml of the sulfuric acid (5.1) and approximately 5 g of the catalyst mixture H= N x 5,62 (5.2). Then heat to b
16、oiling, first with a low and later with a higher flame, until 1 h after all the carbon has been oxidized. where N is as defined in 9.1.1. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 0
17、4/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 5397-1984 (E) 9.2 Repeatability (5.2). Titration of the ammonia is then carried out with acid of one-fifth the concentration specified in 5.5. The results of duplicate determinations carried out by the s
18、ame operator in the same laboratory shall not differ by more than 0,l %, calculated on the original mass of leather. 11 Test report The test report shall include the following particulars : 10 Notes on procedure a) reference to this International Standard; b) complete identification of the sample; 1
19、0.1 With the prescribed mass of test portion and using the acid specified in 5.5 for the titration, the end-point is very clear and sharp. c) the results obtained and the method of expression used; d) any unusual features noted during the determination; IO.2 The determination can also be carried out
20、 with 0,5 g of e) any operation not included in this International Stan- leather weighed to 0,000 2 g and 15 to 20 ml of the concentra- dard or the International Standards to which reference is ted or fuming sulfuric acid (5.1) and 2,5 g of the catalyst made, or regarded as optional. Copyright Inter
21、national Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Org
22、anization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization fo
23、r Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,- This page intentionally left blank Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/26/2007 21:54:51 MDTNo reproduction or networking permitted without license from IHS -,-,-