1、BRITISH STANDARDBS EN ISO 4048:2008Leather Chemical tests Determination of matter soluble in dichloromethane and free fatty acid contentICS 59.140.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g3
2、9g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 4048:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee BSI 2008ISBN 978 0 580 57418 4National forewordThis British Standard is the UK implementation of EN ISO 4048:2008. It supersedes
3、BS EN ISO 4048:1998 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to incl
4、ude all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate Commentson 30 May 2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORME
5、N ISO 4048February 2008ICS 59.140.30 Supersedes EN ISO 4048:1998 English VersionLeather - Chemical tests - Determination of matter soluble indichloromethane and free fatty acid content (ISO 4048:2008)Cuir - Essais chimiques - Dosage des matires solublesdans le dichloromthane et des acides gras libre
6、s (ISO4048:2008)Leder - Chemische Prfungen - Bestimmung der inDichlormethan lslichen Substanzen und des freienFettsuregehalts (ISO 4048:2008)This European Standard was approved by CEN on 3 February 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the con
7、ditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three
8、 official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austr
9、ia, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTE
10、E FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 4048:2008: EEN ISO 4048:2008 (E) Forewor
11、d This document (EN ISO 4048:2008) has been prepared by Technical Committee CEN/TC 289 “Leather“, the secretariat of which is held by UNI in collaboration with Technical Committee ISO/TC IULTCS “International Union of Leather Technologists and Chemists Societies“. This European Standard shall be giv
12、en the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2008, and conflicting national standards shall be withdrawn at the latest by August 2008. Attention is drawn to the possibility that some of the elements of this document may b
13、e the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 4048:1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to i
14、mplement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerl
15、and and the United Kingdom. BS EN ISO 4048:2008ISO 4048:2008(E) IULTCS/IUC 4:2008(E) iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out
16、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, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO coll
17、aborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International St
18、andards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements
19、of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4048/IUC 4 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, in collaboration with the Chemical Tests Com
20、mission of the International Union of Leather Technologists and Chemists Societies (IUC Commission, IULTCS), in accordance with the Agreement on technical co-operation between ISO and CEN (Vienna Agreement). It is based on IUC 4 originally published in J. Soc. Leather Trades Chemists, 49, p. 10, 196
21、5, and declared an official method of the IULTCS in 1965. IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to further the advancement of leather science and technology. IULTCS has three Commissions, which are responsible for establishing international
22、 methods for sampling and the testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation of test methods for leather. This second edition cancels and replaces the first edition (ISO 4048:1977), which has been technically revised. BS EN ISO 4048:2008blankISO
23、4048:2008(E)IULTCS/IUC 4:2008(E)1Leather Chemical tests Determination of matter soluble in dichloromethane and free fatty acid content 1 Scope This International Standard specifies a method for the determination of the substances in leather which are soluble in dichloromethane. This method is applic
24、able to all types of leather. Not all fatty and similar substances can be extracted from leather with organic solvents; they may be in part soluble and partly bound to the leather. On the other hand, the solvent can dissolve non-fatty substances, e.g. sulfur and impregnants, both of which cause diff
25、iculty in the determination of the acid value and saponification value of the fat. This International Standard includes two techniques for extraction of the fatty substances: 1) extraction using the Soxhlet apparatus; and 2) extraction using a pressurized extraction system. As the extraction is freq
26、uently done in conjunction with determination of the free fatty acid content of the leather, a suitable procedure for determination of the free fatty acids extracted by this method is included. The apparatus and technique described in this method are also suitable for the extraction by solvents othe
27、r than dichloromethane (although the temperature conditions may need to be varied for high pressure extraction). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated referen
28、ces, the latest edition of the referenced document (including any amendments) applies. ISO 2418, Leather Chemical, physical and mechanical and fastness tests Sampling location ISO 4044, Leather Chemical tests Preparation of chemical test samples ISO 4098, Leather Chemical tests Determination of wate
29、r-soluble matter, water-soluble inorganic matter and water-soluble organic matter ISO 4684, Leather Chemical tests Determination of volatile matter 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 extractable substances fats and other soluble
30、matter which can be extracted from leather with dichloromethane 3.2 free fatty acid content fatty acid content of the extractable substances as determined by this method and expressed as oleic acid BS EN ISO 4048:2008ISO 4048:2008(E) IULTCS/IUC 4:2008(E) 2 4 Principle The prepared leather is extract
31、ed with dichloromethane. The solvent is evaporated from the extract which is then dried at 102 C. Subsequent analysis can then be performed on the resulting extract to determine the free fatty acid content of the leather. 5 Reagents During analysis, use only reagents of a recognized analytical grade
32、. 5.1 Determination of substances soluble in dichloromethane. 5.1.1 Dichloromethane, boiling point 38 C to 40 C, freshly distilled and kept in a dark flask over calcium oxide. Dichloromethane that has been allowed to stand for a long time should be tested as follows for the presence of any hydrochlo
33、ric acid which may have formed. Shake 10 ml of dichloromethane with 1 ml of 0,1 mol/l silver nitrate solution. If the silver nitrate solution becomes turbid, the dichloromethane should be redistilled and kept in a dark flask over calcium oxide. WARNING Dichloromethane has toxic properties and should
34、 be used with caution. The suppliers handling instructions should be followed. 5.2 Determination of free fatty acid content of the leather. 5.2.1 Mixed solvent, a mixture of equal volumes of diethyl ether and 95 % (volume fraction) ethanol, neutralized with 0,1 mol/l sodium hydroxide (phenolphthalei
35、n is used as the indicator). If, for any purpose, other solvents are used, the solvent or solvents used shall be stated in the test report. 5.2.2 Sodium hydroxide, 0,1 mol/l standard solution. 5.2.3 Phenolphthalein indicator solution, 10 g/l prepared in 95 % (volume fraction) ethanol. In determinati
36、ons on dark coloured solutions, observation of the end point of the titration may be facilitated either by the substitution of thymolphthalein or alkali blue 6B for phenolphthalein. Alternatively, 1 ml of a 0,1 % solution of methylene blue can be added to each 100 ml of the phenolphthalein solution
37、before titration. Phenolphthalein should be used as the preferred option if possible. NOTE Dichloromethane which has been used for this analysis can be recovered and reused after distillation. 6 Apparatus 6.1 Soxhlet extraction apparatus, including an extraction flask of suitable capacity and a cond
38、enser, or pressurized extraction system, including extraction flask of suitable capacity. 6.2 Filter paper thimbles, of suitable sizes, or suitable glass filter bells. 6.3 Oven, capable of being maintained at (102 2) C. 6.4 Analytical balance, capable of weighing to an accuracy of 0,1 mg. 6.5 Desicc
39、ator, suitable for cooling the extraction vessels. 6.6 Glass wool or cotton wad. If a cotton wad is used, this shall be pre-extracted in dichloromethane (5.1.1). BS EN ISO 4048:2008ISO 4048:2008(E) IULTCS/IUC 4:2008(E) 37 Sampling and preparation of the samples If possible, sample in accordance with
40、 ISO 2418. If sampling in accordance to ISO 2418 is not possible, then details about sampling shall be given in the test report. Grind the leather in accordance with ISO 4044. Samples shall be analysed in duplicate. 8 Procedure 8.1 General Weigh accurately using the analytical balance (6.4) (10 0,1)
41、 g of the prepared sample and press evenly into the filter paper thimble or glass bell (6.2). Cover the leather with a thin layer of glass wool or cotton wad (6.6). Dry the extraction flask (see 6.1) with four glass beads in it by heating for 30 min at (102 2) C. Weigh after cooling in a desiccator
42、(6.5). NOTE If determination of free fatty acids is not being carried out, boiling chips may be used as an alternative to glass beads. Two techniques for extraction of the fatty substances are described: 1) extraction using the Soxhlet apparatus (see 8.2); and 2) extraction using a pressurized extra
43、ction system (see 8.3). In the case of dispute, the Soxhlet extraction shall be used. 8.2 Extraction using the Soxhlet apparatus 8.2.1 Place the sample prepared in 8.1 into the extraction apparatus and begin continuous extraction with the dichloromethane (see 8.2.2); then after at least 30 changes o
44、f solvent, distil the dichloromethane from the flask containing the extract (see 8.2.3). Dry the extract for 4 h in the oven (6.3), maintained at (102 2) C (if drops of water are visible before drying, add 1 ml to 2 ml of ethanol). Weigh after cooling for 30 min in a desiccator. Repeat the drying, c
45、ooling and weighing operations, but with drying periods of 1 h, until either the further loss in mass does not exceed 0,01 g, or the total drying time equals 8 h (see 8.2.3). 8.2.2 Dichloromethane (5.1.1) can also dissolve non-fatty materials from the leather, for example sulfur. (The presence of su
46、lfur is recognizable by a yellow precipitate in the flask.) As sulfur causes difficulty, it can be removed in the following way. Dissolve the extract in the smallest possible quantity of diethyl ether and filter through a little cotton wad (6.6) into a previously weighed flask. After thoroughly wash
47、ing out the cotton wad filter with ether, remove the ether from the extract in the flask by distillation over a hot water bath from which any flame has previously been removed. If the sulfur should precipitate again, repeat the procedure. After the diethyl ether has been distilled off, dry the flask
48、 and residue and weigh. 8.2.3 The extract may 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. NOTE After removal of the solvent, the extracted leather can be used for determination of water soluble
49、 substances in accordance with ISO 4098. BS EN ISO 4048:2008ISO 4048:2008(E) IULTCS/IUC 4:2008(E) 4 8.3 Extraction using a pressurized extraction system Place the sample prepared in 8.1 above in the extraction apparatus, and fill with dichloromethane as appropriate. The sample should be boiled at 180 C for 40 min. Following this, sufficient dichloromethane should be distilled from the flask containing the extract to ensure that the extraction thimble is clear of the solvent. Extraction should then continue for a further
