BS EN ISO 1211-2010 Milk - Determination of fat content - Gravimetric method (Reference method)《牛奶 脂肪含量的测定 重量分析法(基准方法)》.pdf

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1、BS EN ISO1211:2010ICS 67.100.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMilk Determinationof fat content Gravimetric method(Reference method)(ISO 1211:2010)This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee

2、on 31 July 2010 BSI 2010ISBN 978 0 580 63070 5Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 1211:2010National forewordThis British Standard is the UK implementation of EN ISO 1211:2010. Itsupersedes BS EN ISO 1211:2001 which is withdrawn.The UK participation in its preparation

3、 was entrusted to TechnicalCommittee AW/5, Chemical analysis of milk and milk products.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for it

4、s correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 1211 June 2010 ICS 67.100.10 Supersedes EN ISO 1211:2001English Version Milk - Determination of fat content - Gravimetric method (Reference m

5、ethod) (ISO 1211:2010) Lait - Dtermination de la teneur en matire grasse - Mthode gravimtrique (Mthode de rfrence) (ISO 1211:2010) Milch - Bestimmung des Fettgehaltes - Gravimetrisches Verfahren (Referenzverfahren) (ISO 1211:2010) This European Standard was approved by CEN on 5 May 2010. CEN members

6、 are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application

7、to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the

8、same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

9、 Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any

10、means reserved worldwide for CEN national Members. Ref. No. EN ISO 1211:2010: EBS EN ISO 1211:2010EN ISO 1211:2010 (E) 3 Foreword This document (EN ISO 1211:2010) has been prepared by Technical Committee ISO/TC 34 “Food products“ in collaboration with Technical Committee CEN/TC 302 “Milk and milk pr

11、oducts - Methods of sampling and analysis” the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2010, and conflicting national standards shall be withd

12、rawn at the latest by December 2010. Attention is drawn to the possibility that some of the elements of this document may be 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 1211:2001. Accord

13、ing to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Ital

14、y, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 1211:2010 has been approved by CEN as a EN ISO 1211:2010 without any modification. BS EN ISO 1211:2010ISO

15、 1211:2010(E) IDF 1:2010(E) ISO and IDF 2010 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle1 5 Reagents.2 6 Apparatus.2 7 Sampling.3 8 Preparation of test sample .4 9 Procedure.4 9.1 General .4 9.2 Test portion4 9.3 Blank test

16、s .4 9.4 Preparation of fat-collecting vessel.5 9.5 Determination 5 10 Calculation and expression of results 7 10.1 Calculation .7 10.2 Expression of results8 11 Precision.8 11.1 Interlaboratory test8 11.2 Repeatability 8 11.3 Reproducibility 8 12 Test report9 Annex A (informative) Notes on procedur

17、es10 Annex B (informative) Alternative procedure using fat-extraction tubes with siphon or wash-bottle fittings.12 Annex C (informative) Interlaboratory trial on raw milk15 Annex D (informative) Interlaboratory trial on raw sheep milk and raw goat milk.17 Bibliography18 BS EN ISO 1211:2010ISO 1211:2

18、010(E) IDF 1:2010(E) iv ISO and IDF 2010 All rights reservedForeword 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 through ISO technical commit

19、tees. 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 collaborates closely with the In

20、ternational 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 Standards. Draft International

21、 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 of this document may be the

22、subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 1211IDF 1 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being published jointl

23、y by ISO and IDF. This third edition of ISO 1211IDF 1 cancels and replaces the second edition (ISO 1211:1999), which has been technically revised. BS EN ISO 1211:2010ISO 1211:2010(E) IDF 1:2010(E) ISO and IDF 2010 All rights reserved vForeword IDF (the International Dairy Federation) is a non-profit

24、 organization representing the dairy sector worldwide. IDF membership comprises National Committees in every member country as well as regional dairy associations having signed a formal agreement on cooperation with IDF. All members of IDF have the right to be represented on the IDF Standing Committ

25、ees carrying out the technical work. IDF collaborates with ISO in the development of standard methods of analysis and sampling for milk and milk products. The main task of Standing Committees is to prepare International Standards. Draft International Standards adopted by the Standing Committees are

26、circulated to the National Committees for endorsement prior to publication as an International Standard. Publication as an International Standard requires approval by at least 50 % of the IDF National Committees casting a vote. Attention is drawn to the possibility that some of the elements of this

27、document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 1211IDF 1 was prepared by the International Dairy Federation (IDF) and Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is bei

28、ng published jointly by IDF and ISO. All work was carried out by the Joint ISO-IDF Project Group on Fat in milk of the Standing Committee on Analytical methods for composition under the aegis of its project leader, Mrs. S. Orlandini (IT). This edition of ISO 1211IDF 1 cancels and replaces IDF 1D:199

29、6, which has been technically revised. BS EN ISO 1211:2010BS EN ISO 1211:2010INTERNATIONAL STANDARD ISO 1211:2010(E)IDF 1:2010(E) ISO and IDF 2010 All rights reserved 1Milk Determination of fat content Gravimetric method (Reference method) WARNING Persons using this International Standard should be

30、familiar with normal laboratory practice. This International Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulato

31、ry conditions. 1 Scope This International Standard specifies the reference method for the determination of the fat content of milk of good physicochemical quality. The method is applicable to raw cow milk, raw sheep milk, raw goat milk, reduced fat milk, skimmed milk, chemically preserved milk, and

32、processed liquid milk. It is not applicable when greater accuracy is required for skimmed milk, e.g. to establish the operating efficiency of cream separators. NOTE ISO 72087specifies a special method for skimmed milk products. 2 Normative references The following referenced documents are indispensa

33、ble for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3889IDF 219, Milk and milk products Specification of Mojonnier-type fat extraction flasks 3 Te

34、rms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fat content of milk mass fraction of substances determined by the procedure specified in this International Standard NOTE The fat content is expressed as a percentage mass fraction. 4 Principle An a

35、mmoniacal ethanolic solution of a test sample is extracted with diethyl ether and light petroleum. The solvents are removed by distillation or evaporation. The mass of the substances extracted is determined. NOTE This is usually known as the Rse-Gottlieb principle. BS EN ISO 1211:2010ISO 1211:2010(E

36、) IDF 1:2010(E) 2 ISO and IDF 2010 All rights reserved5 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, and distilled or demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue when the determination is carried out by

37、the method specified (see 9.3.2). 5.1 Ammonia solution, containing a mass fraction of NH3of approximately 25 % 20(NH3) = 910 g/l. If an ammonia solution of this concentration is not available, a more concentrated solution of known concentration may be used (see 9.5.1). 5.2 Ethanol (C2H5OH), or ethan

38、ol denatured by methanol, containing a volume fraction of ethanol of at least 94 % (see A.4). 5.3 Congo red solution. Dissolve 1 g of Congo red (C32H22N6Na2O6S2) in water in a 100 ml one-mark volumetric flask (6.14). Make up to the mark with water. NOTE The use of this solution, which allows the int

39、erface between the solvent and aqueous layers to be seen more clearly, is optional (see 9.5.2). Other aqueous colour solutions can be used provided that they do not affect the result of the determination. WARNING Congo red is carcinogenic. 5.4 Diethyl ether (C2H5OC2H5), free from peroxides (see A.3)

40、, and complying with the requirements for the blank test (see 9.3.2 and A.2). WARNING The use of diethyl ether can lead to hazardous situations. Observe current safety precautions for handling, use, and disposal. 5.5 Light petroleum, with any boiling range between 30 C and 60 C or, as equivalent, pe

41、ntane (CH3CH23CH3) with a boiling point of 36 C and complying with the requirements for the blank test (see 9.3.2, A.1 and A.2). 5.6 Mixed solvent. Shortly before use, mix equal volumes of diethyl ether (5.4) and light petroleum (5.5). 6 Apparatus WARNING Since the determination involves the use of

42、volatile flammable solvents, all electrical apparatus employed shall comply with legislation relating to the hazards in using such solvents. Usual laboratory equipment and, in particular, the following. 6.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0,1 mg. 6.

43、2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a rotational frequency of 500 min1to 600 min1to produce a radial acceleration of 80g to 90g at the outer end of the flasks or tubes. The use of the centrifuge is optional, but recommended (see 9.5.5)

44、. BS EN ISO 1211:2010ISO 1211:2010(E) IDF 1:2010(E) ISO and IDF 2010 All rights reserved 36.3 Distillation or evaporation apparatus, suitable for distilling the solvents and ethanol from the boiling or conical flasks, or evaporating from dishes (see 9.5.12) at a temperature not exceeding 100 C. 6.4

45、Drying oven, electrically heated, with ventilation port(s) fully open, capable of operating at a temperature of 102 C 2 C throughout its working space. The oven shall be fitted with a suitable thermometer. 6.5 Water bath, capable of maintaining a temperature between 35 C and 40 C. 6.6 Mojonnier type

46、 fat-extraction flasks, as specified in ISO 3889IDF 219. NOTE It is also possible to use fat-extraction tubes, with siphon or wash-bottle fittings, but the procedure is then different (see Annex B). The fat-extraction flasks shall be provided with good quality cork bungs or stoppers of other materia

47、l e.g. silicone rubber or polytetrafluoroethylene (PTFE) unaffected by the reagents used. Cork bungs shall be extracted with the diethyl ether (5.4), kept in water at a temperature of 60 C or more for at least 15 min, and shall then be allowed to cool in the water so that they are saturated when use

48、d. 6.7 Rack, suitable for holding the fat-extraction flasks (or tubes) (6.6). 6.8 Wash bottle, suitable for use with the mixed solvent (5.6). A plastics wash bottle shall not be used. 6.9 Fat-collecting vessels, such as boiling flasks (flat-bottomed), of capacities 125 ml to 250 ml, conical flasks,

49、of capacity 250 ml, or metal dishes. If metal dishes are used, they shall be of stainless steel, flat-bottomed with a diameter of 80 mm to 100 mm and a height of approximately 50 mm. 6.10 Boiling aids, fat-free, of non-porous porcelain, silicon carbide or glass. Their use is optional. 6.11 Measuring cylinders, capacities 5 ml and 25 ml, ISO 47884class A, or any other apparatus suitable for the product concerned. 6.12 Pipettes, graduated, capacity 10 ml, ISO 8352class A. 6.13 Tongs, made of metal, suitabl