EN ISO TS 17764-1-2006 en Animal feeding stuffs - Determination of the content of fatty acids - Part 1 Preparation of methyl esters《动物饲料 脂肪酸含量的测定 第1部分 甲酯的制备》.pdf

1、DRAFT FOR DEVELOPMENTDD CEN ISO/TS 17764-1:2006Incorporating amendment no. 1 (renumbers DD ISO/TS 17764-1:2002 as DD CEN ISO/TS 17764-1:2006)Animal feeding stuffs Determination of the content of fatty acids Part 1: Preparation of methyl estersICS 65.120g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g

2、56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD CEN ISO/TS 17764-1:2006This Draft for Development, having been prepared under the direction of the Consumer Products and Services Sector Policy

3、and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 20 December 2002 BSI 2007ISBN 0 580 40991 0National forewordThis Draft for Development is the official English language version of CEN ISO/TS 17764-1:2006. It is identical with ISO/TS 17764-1:

4、2002.This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature because of the need to carry out collaborative trials to validate this method. It should be applied on this provisional basis, so t

5、hat information and experience of its practical application may be obtained. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for the Technical Specification. A review of this publication wil

6、l be initiated not later than 3 years after its publication by the international organization so that a decision can be taken on its status at the end of its 3-year life. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards.Accor

7、ding to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international standard, to extend the life of the Technical Specification for another 3 years or to withdraw it. Comments should be sent in writing to the

8、 Secretary of BSI Technical Committee AW/10, Animal feeding stuffs, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where possible, an appropriate revision of the text.A list of organizations represented on this commit

9、tee can be obtained on request to its secretary. Amendments issued since publicationAmd. No. Date Comments16946 28 February 2007 Renumbers DD ISO/TS 17764-1:2002 as DD CEN ISO/TS 17764-1:2006TECHNICAL SPECIFICATIONSPCIFICATION TECHNIQUETECHNISCHE SPEZIFIKATIONCEN ISO/TS 17764-1October 2006ICS 65.120

10、English VersionAnimal feeding stuffs - Determination of the content of fattyacids - Part 1: Preparation of methyl esters (ISO/TS 17764-1:2002)Aliments des animaux - Dtermination de la teneur enacides gras - Partie 1: Prparation des esters mthyliques(ISO/TS 17764-1:2002)Futtermittel - Bestimmung des

11、Gehaltes an Fettsuren -Teil 1: Vorbereitung von Methylestern (ISO/TS 17764-1:2002)This Technical Specification (CEN/TS) was approved by CEN on 13 February 2006 for provisional application.The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN wi

12、ll be requested to submit theircomments, particularly on the question whether the CEN/TS can be converted into a European Standard.CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS availablepromptly at national level in an appropria

13、te form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)until the final decision about the possible conversion of the CEN/TS into an EN is reached.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia

14、, 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 COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES

15、KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. CEN ISO/TS 17764-1:2006: EForeword This document (CEN ISO/TS 17764-1:2006) has been prepared by Technical Comm

16、ittee CEN/TC 327 “Animal feeding stuffs - Methods of sampling and analysis“, the secretariat of which is held by NEN, in collaboration with Technical Committee ISO/TC 34 “Agricultural food products“. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the follo

17、wing countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slove

18、nia, Spain, Sweden, Switzerland and United Kingdom. CEN ISO/TS 17764-1:2006Reference numberISO/TS 17764-1:2002(E)TECHNICAL SPECIFICATION ISO/TS17764-1First edition2002-11-01Animal feeding stuffs Determination of the content of fatty acids Part 1: Preparation of methyl esters Aliments des animaux Dte

19、rmination de la teneur en acides gras Partie 1: Prparation des esters mthyliques CEN ISO/TS 17764-1:2006ISO/TS 17764-1:2002(E) DPlcsid Fremia ihTs PDF file may ctnoian emdebt dedyfepcaes. In ccaocnadrw eith Aebods licensilop gnic,y this file mairp eb ynted iv roweb detu slahl ton ide ebtlnu deess te

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22、 ehikletneve y ttah lborp aem leratign to it is f,dnuo lpsaee inform ttneC ehlar Secrteiraat ta the serddaig sleb nevwo. ISO 2002 Athgir lls serevr.de selnUs towrehise specfidei, trap on fo thsi ilbupctanoi may cudorper ebtu ro dezilina ni dey fomr yb ro nam y,snae lecetrinoc ro mecinahcal, inclidun

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24、i n Switlrez dnaii ISO 2002 Allr ihgtsser edevriiISO/TS 17764-1:2002(E) I SO 2002 All irhgts seredevr 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 norm

25、ally carried out 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 t

26、he work. ISO collaborates 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

27、 International Standards. 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. In other circumstances, particularly when there

28、 is an urgent market requirement for such documents, a technical committee may decide to publish other types of normative document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an ISO working group and is accepted for publication if it is app

29、roved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a vote. An ISO/

30、PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either be t

31、ransformed into an International Standard or be withdrawn. Attention is drawn to the possibility that some of the elements 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/TS 17764-1 was prepared by Technical C

32、ommittee ISO/TC 34, Food products, Subcommittee SC 10, Animal feeding stuffs. ISO/TS 17764 consists of the following parts, under the general title Animal feeding stuffs Determination of the content of fatty acids: Part 1: Preparation of methyl esters Part 2: Gas chromatographic method iiiCEN ISO/TS

33、 17764-1:2006blankTECINHCAICEPS LFICATION IS/OTS -46771:12002(E)I SO 2002 All irhgts seredevr 1Animal feeding stuffs Determination of the content of fatty acids Part 1: Preparation of methyl esters 1 Scope ISO/TS 17764 specifies methods for the quantitative determination of individual fatty acids an

34、d of the sum of the fatty acids (elutable fatty acids). This part of ISO/TS 17764 specifies two methods for preparing the methyl esters of fatty acids of animal and vegetable fats, oils and fatty acid mixtures for raw materials for compound animal feeds, and fatty acids originating from fat extracts

35、 of animal feeding stuffs, including fats and fatty acid mixtures containing butyric acid. The general method, the boron trifluoride (BF3) method, is concerned with the preparation of methyl esters of fatty acids with six or more C atoms, originating from fats, oils and free fatty acids. The KOH/HCl

36、 method is concerned with the preparation of methyl esters of fatty acids with four or more C atoms. This method can also be used for the quantitative determination of fatty acids with a chain length shorter than ten C atoms in free fatty acid mixtures. The methyl esters produced can be used for gas

37、-liquid chromatography (GLC). NOTE 1 Unsaponifiable materials are not removed and can, when present in considerable amounts, interfere with the chromatographic analysis. NOTE 2 ISO/TS 17764-2 describes the application of gas chromatography with capillary columns and flame ionization detection for th

38、e determination of the content of fatty acids in a fat by making use of the methyl esters of the fatty acids obtained in accordance with the methods specified in this part of ISO/TS 17764. 2 Normative references The following referenced documents are indispensable for the application of this documen

39、t. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 661:1989, Animal and vegetable fats and oils Preparation of test sample ISO 3696:1987, Water for analytical laboratory use Specificat

40、ion and test methods ISO 6492:1999, Animal feeding stuffs Determination of fat content 1CEN ISO/TS 17764-1:2006ISO/TS 17764-1:2002(E) 2 I SO 2002 All irhgts seredevr3 Fat extraction 3.1 General Extract the fat for determination of the content of the saponifiable fatty acids in an animal feeding stuf

41、f or mixed feed in accordance with the category of the feeding stuff, as described in ISO 6492:1999, with the following amendments. 3.2 Samples of category A Perform a fat extraction in accordance with 9.5.1 of ISO 6492:1999. Evaporate the solvent with a rotating evaporator in a water bath at a temp

42、erature of not more than 40 C. Then dry the residue for 2 h in a vacuum drying oven at 40 C 2 C. 3.3 Samples of category B Extract the fat in two steps. For the first step, proceed in accordance with 9.5.1 of ISO 6492:1999, treating the test portion as described in 9.3 of ISO 6492:1999 as a sample o

43、f category A. Collect the fat extract in a dry flask. Allow the solvent to evaporate from the residue by exposing the thimble to the air. Perform a hydrolysis of the residue in accordance with 9.4 of ISO 6492:1999. After hydrolysis, dry the residue in an extraction thimble for 60 min in a vacuum dry

44、ing oven at 40 C 2 C. Extract the residue according to 9.5.1 of ISO 6492:1999. Add the fat extract to the first extract. Evaporate the solvent with a rotating evaporator in a water bath at a temperature of not more than 40 C and dry the residue for 2 h in a vacuum drying oven at 40 C 2 C. 4 Preparat

45、ion of test sample of fat or fat extract If the fat sample or the fat extract is not completely molten, heat the sample to a temperature of not more than 10 C above the melting temperature. See ISO 661. 5 Method for the preparation of methyl esters of fatty acids with six or more C atoms (BF3method)

46、 5.1 Principle The glycerides are saponified with methanolic sodium hydroxide. The soaps are converted to methyl esters by reaction with a boron trifluoride/methanol complex. 5.2 Reagents Use only reagents and solvents of recognized analytical grade. 5.2.1 Water, complying with at least grade 3 in a

47、ccordance with ISO 3696:1987. 5.2.2 Heptadecanoic acid (internal standard), of purity at least 99 %. 2CEN ISO/TS 17764-1:2006ISO/TS 17764-1:2002(E) I SO 2002 All irhgts seredevr 35.2.3 Sodium hydroxide, methanolic solution, c(NaOH) 0,5 mol/l. Dissolve 2 g of sodium hydroxide in 100 ml of methanol co

48、ntaining not more than 0,5 % (mass fraction) of water. If the solution has to be stored for a considerable time, a small amount of white precipitate of sodium carbonate can form; this has no effect on the preparation of the methyl esters. Instead of sodium hydroxide, a methanolic solution of potassi

49、um hydroxide with the same concentration may be used. 5.2.4 Boron trifluoride (BF3), methanolic solution, 10 % to 15 % (mass fraction). WARNING Boron trifluoride is poisonous. For this reason, it is not recommended that the analyst prepare the methanolic solution of boron trifluoride from methanol and boron trifluoride. Solutions are available commercially. In gas chromatographic analysis of the methyl esters, certain reagents can give rise to peaks which interfere with the analysis. In particular, BF3solut