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1、- Lu INTERNATIONAL STANDARD. INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l MEXAYHAPOAHAR OPl-AHM3AUMR I-Io CTAHAAPTM3AWH-ORGANISATION INTERNATIONALE DE NORMALISATION Leather - Determination of matter soluble in dichloromethane Cuir - Dosage des matikes solubles dans Ie dichloromethane First editi
2、on - 1977-11-01 UDC 675 : 543.832 Ref. No. ISO 4048-1977 (El Descriptots : leather, Chemical analysis, quantitative analysis, determination of content, dissolved matter, extraction analysis, dichloro- methane. Price based on 2 pages Copyright International Organization for Standardization Provided b
3、y IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:43:50 MDTNo reproduction or networking permitted without license from IHS -,-,- FOREWORD ISO (the International Organization for Standardization) is a worldwide federation of national Standards
4、institutes (!SO 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, go
5、vernmental 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 4048
6、was developed by Technical Committee ISO/TC 120, Leather, and was circulated to the member bodies in August 1976. lt has been approved by the member bodies of the following countries : Australia Hungary Brazil I ndia Chile Israel Czechoslovakia Mexico France Netherlands Germany New Zealand Poland Ro
7、mania South Africa, Rep. of Turkey United Kingdom The member body of on technical grounds : the following country expressed disapproval of the document U.S.S. R. This International Standard is based on method lUC/4 of the International Union of Leather Technologists and Chemists Societies. 0 Interna
8、tional Organkation for Standardkation, 1977 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, 04/25/2007 21:43:50 MDTNo reproduction or networking permitted without l
9、icense from IHS -,-,- INTERNATIONAL STANDARD ISO 4048-1977 (E) Leather - Determination of matter soluble in dichloromethane 0 INTRODUCTION Not all fatty and similar substances tan be extracted from leather with organic solvents; they may be partly soluble and partly bound to the leather. On the othe
10、r hand, the solvent may dissolve non-fatty substances, for example sulphur and impregnants, both of which Cause difficulty in the determination of the acid and saponification values of the fats. NOTE - The apparatus and procedure specified in this method are also suitable for the extraction of leath
11、er by solvents other than dichloromethane. lf, for any purpose, other solvent-s are used, the solvent or solvents used should be stated in the test report. 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies a method for the determination of the substances in leather which are sol
12、uble in dichloromethane. This method is applicable to all types of leather. 2 REFERENCES ISO 2418, Leather - Laboratory samples - Location and iden tifica tion. ISO 2588, leather - Sampling - Number of items for a gross Sample. ISO 4044, Leather - Preparation of Chemical test samples. 1) ISO 4098, L
13、eather - Determination o f wa ter-soluble matter, wa ter-soluble inorganic matter, and wa ter-soluble organic matter. 1) 3 DEFINITION For the purposes of this International Standard, the follow- ing definition applies : extractable substances : Fats and other soluble matter which tan be extracted fr
14、om leather with dichloromethane. 4 PRINCIPLE Continuous extraction of a Sample of the prepared leather with dichloromethane. Evaporation of the solvent from the extract. Drying of the extract at 102 + 2 “C and weighing. 5 REAGENTS During the analysis, use only reagents of recognized ana- lytical gra
15、de. 5.1 Dichloromethane, boiling Point 38 to 40 C, freshly distilled and kept in a dark flask over Calcium Oxide. WARNING - Dichloromethane has toxic properties and should be used with caution. NOTES 1 Dichloromethane that has stood for a long time should be tested for the presence of any hydrochlor
16、ic acid which may have formed, as follows : Shake 10 ml of dichloromethane with 1 ml of 0,l N silver nitrate solution. If the silver nitrate solution becomes turbid, the dichloro- methane should be redistilled and kept in a dark flask over Calcium Oxide. 2 Dichloromethane which has been used for thi
17、s analysis tan be recovered and reused after distillation. 6 APPARATUS Ordinary laboratory apparatus and in particular 6.1 Soxhlet extraction apparatus, including an extraction flask of suitable capacity and a condenser. 6.2 Filter Paper thimbles, of suitable sizes and manu- facture, or suitable gla
18、ss filter bells. 6.3 Oven, capable of being maintained at 102 + 2 “C. 7 SAMPLING 7.1 Whole pieces of leather In the absence of any other agreement on sampling between the interested Parties, the procedure specified in ISO 2588 for sampling from a lot shall be followed. Samples shall be taken from th
19、e pieces as specified in ISO 2418. 7.2 Other applications Sampling shall be carried out as required by the relevant specification or contract. 1) At present at the Stage of draft. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical
20、Standards 1/9972545001 Not for Resale, 04/25/2007 21:43:50 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 4048-1977 (E) 8 PROCEDURE 9 EXPRESSION OF RESULTS Prepare the Sample as specified in ISO 4044. 9.1 Calculation Weigh 10 rt: 0,l g of the prepared Sample and press
21、evenly into a filter Paper thimble or glass bell (6.2). Cover the leather with a thin layer of cottonwad, previously extracted with the dichloromethane (5.1). Dry the extraction flask (see 6.1) with two glass beads in it by heating for 30 min at 102 + 2 “C. Weigh after cooling in a desiccator. Begin
22、 the continuous extraction with the dichloromethane (sec note 1); then, after at least 30 changes of solvent, distil the dichloromethane from the flask containing the extract (see note 2). Dry the extract for 4 h in the oven (6.3), maintained at 102 t 2 “C (if drops of water are visible before dryin
23、g, add 1 to 2 ml of ethanol). Weigh after cooling for 30 min in a desiccator. Repeat the drying, cooling and weighing operations at least three times, but with drying periods of 1 h, until either the further loss in mass does not exceed 0,Ol g, or the total drying time equals 8 h (see note 3). 1 Dic
24、hloromethane tan also dissolve non-fatty materials from the leather, for example sulphur (the presence of sulphur is recognizable by a yellow precipitate in the flask). As sulphur Causes difficulty, it tan be removed in the following way : Dissolve the extract in the smallest possible quantity of di
25、ethyl ether and filter through a little cottonwad into a previously weighed flask. After thoroughly washing out the cottonwad filter with ether, remove the ether from the extract in the flask by distil- lation over a hot water bath from which any flame has previously been removed. If sulphur should
26、again precipitate, repeat the procedure. After the diethyl ether has been distilled off, dry the flask and residue and weigh. 2 The extract tan be used for analysis, for example to determine acid and saponification values of the fats, or to determine the free fatty acid content of the leather. 3 Aft
27、er removal of the solvent, the extract may be used for deter- mi nation of water-sol u ble su bstan ces in accordance with ISO 4098. The matter extractable in dichloromethane or other speci- fied solvent(s) is given, as a percentage by mass, by the formula m1 XI00 mO where MO m1 is the mass, in gram
28、s, of the test Portion; is the mass, in grams, of the extract. 9.2 Repeatability The results of duplicate determinations carried out by the same Operator in the same laboratory should not differ by more than 0,2 %, calculated on the original mass of leather. 9.3 Reproducibility The results of two de
29、terminations carried out by different Operators in different laboratories on the same Sample should not differ by more than 0,5 %, calculated on the original mass of Ieather. IO TEST REPORT The test report shall include the following particulars : a) a reference to this International Standard; b) co
30、mplete identification of the Sample; 4 the characteristics of the solvent; d) the resu mean value; Its obtained, to one d ecimal place, and the e) details of any special circumstances which may have affected the results. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:43:50 MDTNo reproduction or networking permitted without license from IHS -,-,-