1、November 2010 Translation by DIN-Sprachendienst.English price group 13No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I
2、CS 67.100.10!$l1x“1731485www.din.deDDIN EN ISO 1211Milk Determination of fat content Gravimetric method (Reference method) (ISO 1211:2010)English translation of DIN EN ISO 1211:2010-11Milch Bestimmung des Fettgehaltes Gravimetrisches Verfahren (Referenzverfahren) (ISO 1211:2010)Englische bersetzung
3、von DIN EN ISO 1211:2010-11Lait Dtermination de la teneur en matire grasse Mthode gravimtrique (Mthode de rfrence) (ISO 1211:2010)Traduction anglaise de DIN EN ISO 1211:2010-11SupersedesDIN EN ISO 1211:2001-11www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be
4、 considered authoritative.2511.10 DIN EN ISO 1211:2010-11 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommittee SC 5 “Milk and milk products” (Secretariat: NEN, Netherland
5、s) in collaboration with Technical Committee CEN/TC 302 “Milk and milk products Methods of sampling and analysis” (Secretariat: NEN, Netherlands). The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Prod
6、ucts Standards Committee), Working Committee NA 057-05-13 AA Milch und Milchprodukte Probenahme- und Untersuchungsverfahren. Based on the results of parallel voting, ISO 1211:2010 has been adopted as a European Standard. In Germany, for the purposes of environmental protection and occupational healt
7、h and safety, the employers liability insurance associations and labour inspectorate prohibit the open evaporation of diethyl ether, which is one of the possible procedures specified in this standard. A further means of risk reduction is the substitution of the same amount of methyl tertiary butyl e
8、ther (MTBE) (IUPAC name: 2-methoxy-2-methylpropane) for diethyl ether. This deviation from the specified procedure shall be noted in the test report. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 707 DIN EN ISO 707 ISO 835 DIN EN ISO
9、835 ISO 1042 DIN EN ISO 1042 ISO 4788 DIN EN ISO 4788 ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO 7208 DIN EN ISO 7208 Amendments This standard differs from DIN EN ISO 1211:2001-11 as follows: a) the scope has been extended to include sheep and goat milk; b) the results of interlaborator
10、y trials on sheep and goat milk have been included; c) Clause 2 “Normative references” and Clause 7 “Sampling” have been revised; d) the standard has been revised in form and substance and brought in line with the current rules of presentation; e) the Bibliography has been amended. DIN EN ISO 1211:2
11、010-11 3 Previous editions DIN 10312: 1971-05 DIN 10312-1: 1990-02 DIN EN ISO 1211: 1995-08, 2001-11 National Annex NA (informative) Bibliography DIN EN ISO 707, Milk and milk products Guidance on sampling DIN EN ISO 835, Laboratory glassware Graduated pipettes DIN EN ISO 1042, Laboratory glassware
12、One-mark volumetric flasks DIN EN ISO 4788, Laboratory glassware Graduated measuring cylinders DIN EN ISO 7208, Skimmed milk, whey and buttermilk Determination of fat content Gravimetric method (Reference method) DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Pa
13、rt 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN EN ISO 1211:2010-11 4 This page is intentionally blank EU
14、ROPEAN 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 method) (ISO 1211:2010) Lait - Dtermination de la teneur en matire grasse - Mthode gravimtrique (Mthode d
15、e 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 are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving
16、 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 to the CEN Management Centre or to any CEN member. This European Standard exists in three official versi
17、ons (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 same status as the official versions. CEN members are the national standards bodies of Austria, Belgium,
18、 Bulgaria, Croatia, 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
19、E 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 means reserved worldwide for CEN national Members. Ref. No. EN ISO 1211:2010: EContents DIN EN ISO 1211:
20、2010-11 EN ISO 1211:2010 (E) 2 Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle4 5 Reagents.5 6 Apparatus .5 7 Sampling.6 8 Preparation of test sample7 9 Procedure .7 9.1 General7 9.2 Test portion 7 9.3 Blank tests7 9.4 Preparation of fat-collecting vessel.8 9
21、.5 Determination.8 10 Calculation and expression of results.10 10.1 Calculation10 10.2 Expression of results 11 11 Precision.11 11.1 Interlaboratory test 11 11.2 Repeatability.11 11.3 Reproducibility.11 12 Test report 12 Annex A (informative) Notes on procedures 13 Annex B (informative) Alternative
22、procedure using fat-extraction tubes with siphon or wash-bottle fittings .15 Annex C (informative) Interlaboratory trial on raw milk 18 Annex D (informative) Interlaboratory trial on raw sheep milk and raw goat milk .20 Bibliography 21 Foreword This document (EN ISO 1211:2010) has been prepared by T
23、echnical Committee ISO/TC 34 Food products” in collaboration with Technical Committee CEN/TC 302 “Milk and milk products Methods of samplingThis 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
24、 2010, and conflicting national standards shall be withdrawn 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 r
25、ights. This document supersedes EN ISO 1211:2001. According 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,
26、France, Germany, Greece, Hungary, Iceland, Ireland, Italy, 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 12
27、11:2010 without any modification. “and analysis” the secretariat of which is held by NEN. DIN EN ISO 1211:2010-11 EN ISO 1211:2010 (E) 3 WARNING Persons using this International Standard should be familiar with normal laboratory practice. This International Standard does not purport to address all o
28、f 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 regulatory conditions. 1 Scope This International Standard specifies the reference method for the determination
29、 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 processed liquid milk. It is not applicable when greater accuracy is required for skimmed milk, e.g. to
30、 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 indispensable for the application of this document. For dated references, only the edition cited applies. For und
31、ated 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 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 f
32、at 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 ammoniacal ethanolic solution of a test sample is extracted with diethyl ether and light petroleum. The
33、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. DIN EN ISO 1211:2010-11 EN ISO 1211:2010 (E) 4 5 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, a
34、nd distilled or demineralized water or water of equivalent purity. The reagents shall leave no appreciable residue when the determination is carried out by 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
35、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 ethanol 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
36、(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 interface between the solvent and aqueous layers to be seen more clearly, is optional (see 9.5.2). Other aqueous colour solutions can be used provi
37、ded 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), 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.
38、 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, pentane (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 solve
39、nt. 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 volatile flammable solvents, all electrical apparatus employed shall comply with legislation relating to the hazards in using such solvents. Usu
40、al 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. 6.2 Centrifuge, capable of holding the fat-extraction flasks or tubes (6.6) and capable of spinning at a rotational frequency of 500 min1to 600 mi
41、n1to 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). DIN EN ISO 1211:2010-11 EN ISO 1211:2010 (E) 5 6.3 Distillation or evaporation apparatus, suitable for distilling the solvents and ethanol fro
42、m the boiling or conical flasks, or evaporating from dishes (see 9.5.12) at a temperature not exceeding 100 C. 6.4 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 s
43、uitable thermometer. 6.5 Water bath, capable of maintaining a temperature between 35 C and 40 C. 6.6 Mojonnier type 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 (
44、see Annex B). The fat-extraction flasks shall be provided with good quality cork bungs or stoppers of other material 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 6
45、0 C or more for at least 15 min, and shall then be allowed to cool in the water so that they are saturated when used. 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
46、.9 Fat-collecting vessels, such as boiling flasks (flat-bottomed), of capacities 125 ml to 250 ml, conical flasks, 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.
47、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
48、, made of metal, suitable for holding flasks, beakers or dishes. 6.14 One-mark volumetric flask, capacity 100 ml, ISO 10423class A. 7 Sampling Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 707IDF 501. It is important the la
49、boratory receive a truly representative sample which has not been damaged or changed during transport or storage. Store laboratory samples at a temperature of between 2 C and 6 C from the time of sampling to the time of commencing the procedure. DIN EN ISO 1211:2010-11 EN ISO 1211:2010 (E) 6 8 Preparation of test sample Using the water bath (6.5), warm the test sample to a temperature of 38 C 2 C. Gently mix the test sample thoroughly without causing frothing or churning. Then co
