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1、DRAFT FOR DEVELOPMENT DD CEN ISO/TS 17764-2:2006 Animal feeding stuffs Determination of the content of fatty acids Part 2: Gas chromatographic method ICS 65.120 ? Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI
2、 DD CEN ISO/TS 17764-2:2006 This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 28 February 2007 BSI 2007 ISBN 978 0 580 50176 0 National foreword This Draft for Development was published by BSI. It is the UK implementation of CEN ISO/TS 177
3、64-2:2006. 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. It should be applied on this provisional basis, so that information and experience of its practical application can be obtai
4、ned. Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion to a European standard. A review of this publication will be initiated not later than 3 years after its publication by the
5、European organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will deci
6、de whether to support the conversion into a European Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL. The UK participat
7、ion in its preparation was entrusted to Technical Committee AW/10, Animal feeding stuffs. A list of organizations represented on AW/10 can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its c
8、orrect application. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN ISO/TS 1
9、7764-2 October 2006 ICS 65.120 English Version Animal feeding stuffs - Determination of the content of fatty acids - Part 2: Gas chromatographic method (ISO/TS 17764- 2:2002) Aliments des animaux - Dtermination de la teneur en acides gras - Partie 2: Mthode par chromatographie en phase gazeuse (ISO/
10、TS 17764-2:2002) Futtermittel - Bestimmung des Gehaltes an Fettsuren - Teil 2: Gaschromatographisches Verfahren (ISO/TS 17764- 2:2002) 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
11、 to three years. After two years the members of CEN will be requested to submit their comments, 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 CE
12、N/TS available promptly at national level in an appropriate 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
13、 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, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE
14、 FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN ISO/TS 17764-2:2006: E Licensed Copy: Lo
15、ndon South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI Foreword This document (CEN ISO/TS 17764-2:2006) has been prepared by Technical Committee CEN/TC 327 “Animal feeding stuffs - Methods of sampling and analysis“, the secretariat of
16、 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 following countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus
17、, 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. CEN ISO/TS 17764-2:2006 Licensed Copy: Lond
18、on South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI Reference number ISO/TS 17764-2:2002(E) TECHNICAL SPECIFICATION ISO/TS 17764-2 First edition 2002-11-01 Animal feeding stuffs Determination of the content of fatty acids Part 2: Gas
19、 chromatographic method Aliments des animaux Dtermination de la teneur en acides gras Partie 2: Mthode par chromatographie en phase gazeuse CEN ISO/TS 17764-2:2006 Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BS
20、I ii Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of
21、 preparing International Standards is normally 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
22、, in liaison with ISO, also take part in the 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
23、task of technical committees is to prepare 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 ot
24、her circumstances, particularly when there 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 an
25、d is accepted for publication if it is approved 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 member
26、s of the committee casting a vote. An ISO/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 thre
27、e years, at which time it must either be transformed 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.
28、ISO/TS 17764-2 was prepared by Technical Committee 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
29、: Gas chromatographic method CEN ISO/TS 17764-2:2006 Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI blank Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:0
30、0 2007, Uncontrolled Copy, (c) BSI 1 Animal feeding stuffs Determination of the content of fatty acids Part 2: Gas chromatographic method 1 Scope ISO/TS 17764 specifies methods for the quantitative determination of individual fatty acids and of the sum of the fatty acids (elutable fatty acids). This
31、 part of ISO/TS 17764 specifies the application of gas chromatography with capillary columns and flame ionization detection for the determination of the quantitative content of fatty acids in a fat by making use of the methyl esters of the fatty acids obtained in accordance with the method specified
32、 in ISO/TS 17764-1. This part of ISO/TS 17764 is applicable to the investigation of animal and vegetable fats, oils and fatty acid mixtures for incorporation in animal feeding stuffs and fat extracts of animal feeding stuffs and raw materials for compound animal feeds, including fats and fatty acid
33、mixtures containing butyric acid. This method is not applicable to polymerized fatty acids. 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 references, the latest editi
34、on of the referenced document (including any amendments) applies. ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO/TS 17764-1, Animal feeding stuffs Determination of the content of fatty acids Part 1: Preparation of methyl esters 3 Terms and definitions For the p
35、urposes of this document, the following terms and definitions apply. 3.1 fatty acid content mass fraction of the fatty acids in the test portion of oil, fat, fat extract, free fatty acids or soaps NOTE The fatty acid content is expressed in grams per kilogram. 3.2 content of elutable material mass f
36、raction of the sum of all the fatty acids elutable using a gas chromatographic column as described in this part of ISO/TS 17764 CEN ISO/TS 17764-2:2006 Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 2 4 Princi
37、ple The methyl esters prepared from fatty acids in accordance with ISO/TS 17764-1 are separated with gas-liquid chromatography, making use of a capillary column. The peaks in the chromatogram are defined with the help of a reference sample of known composition and are quantified by means of an inter
38、nal standard. 5 Reagents Use only reagents and solvents of recognized analytical grade. 5.1 Water, complying with at least grade 3 in accordance with ISO 3696:1087. 5.2 n-Hexane or n-heptane. 5.3 n-Pentane. 5.4 Reference sample: an oil or fat sample with exactly known fatty acid pattern, or a mixtur
39、e of reference fatty acid methyl ester materials or reference fatty acids materials. NOTE If the BF3 method for esterification is used, a mixture of reference fatty acid methyl esters cannot be used for calibration or correction factors for fatty acids with a chain length of less than 10 carbon atom
40、s, because of possible solubility of the methyl esters in the water phase. 6 Apparatus Usual laboratory equipment and, in particular, the following. 6.1 Gas chromatograph, comprising a capillary column and an injection system specially designed for use with such columns. It may be of the split or th
41、e split-less type or a cold on-column injector. However, a warm split-less injector is not suitable for the analysis of milk fats due to overlap of the solvent peak with the butyric acid peak. 6.2 Column, constructed of inert material (fused silica or glass) with a stationary phase preferable chemic
42、ally bonded to the wall of the column. Column dimensions and film thickness are important factors in determining the separation efficiency and capacity of the column. A resolution of at least 1,25 for the fatty acids C16:0 and C16:1, and C18:0 and C18:1 should be accomplished. NOTE In most cases a m
43、oderately polar phase will suit. In special cases, for instance for the separation of cis-trans- isomers and/or positional isomers, or if one must be sure that no peaks coincide, a more polar phase is warranted. The desirable effectiveness and capacity of the column should also be considered for col
44、umn dimensions and film thickness. Moderately polar phases are, for instance, various esters of poly(ethylene glycol). More polar phases are often of the cyano-propyl-polysiloxane type. 6.3 Injection system, for manual injection, with a capacity of at most 10 l, and graduated in 0,1 l divisions, sui
45、ted for the injector (6.2), or an automatic injection system. NOTE The use of an automatic system is preferable and can improve repeatability and reproducibility. 6.4 Signal evaluation apparatus: an electronic system fitted with a recorder to transform the detector signal to a chromatogram (an integ
46、rator or a data station). CEN ISO/TS 17764-2:2006 Licensed Copy: London South Bank University, London South Bank University, Thu Mar 01 08:50:43 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 3 7 Procedure 7.1 Preparation of methyl esters Prepare the methyl esters of the fatty acids of the test portion
47、and the reference sample (5.4) in accordance with ISO/TS 17764-1. 7.2 Selection of optimum operating conditions Optimize the equipment in accordance with the instructions given by the manufacturer. Optimize the flow of carrier gas in accordance with the recommendations of the column manufacturer for
48、 the chosen column and the carrier gas. Maintain a detector temperature of 20 C to 50 C above the highest temperature of the column in a programmed heating, but at least at 150 C. The injector temperature depends on the type of the injector; follow the instructions given in the equipment manual. Whe
49、n using a split injector, set the split ratio between 1:30 and 1:100. 7.3 Analysis 7.3.1 Dissolve the fatty acid methyl esters of the test portion and the test portion with added internal standard in n-hexane (5.2) to a content of 1 % (mass fraction) when using a split injector, or 0,05 % (mass fraction) in the case of a split-less injector or a cold on-column injector. Prepare a solution of the fatty acid methyl esters of the reference sample (7.1) in n-hexane with a co