1、DRAFT FOR DEVELOPMENTDD CEN/TS 15568:2006Foodstuffs Methods of analysis for the detection of genetically modified organisms and derived products Sampling strategiesICS 67.050g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g
2、51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD CEN/TS 15568:2006This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 31 May 2007 BSI 2007ISBN 978 0 580 50836 3National forewordThis Draft for Development was publi
3、shed by BSI. It is the UK implementation of CEN/TS 15568:2006.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 ex
4、perience of its practical application can be obtained.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
5、 later than 3 years after its publication by the 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
6、 period, the responsible BSI Committee will decide 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 Chis
7、wick High Road, London W4 4AL.The UK participation in its preparation was entrusted to Technical Committee AW/-/3, Food analysis Horizontal methods.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the n
8、ecessary provisions of a contract. Users are responsible for its correct application.Amendments issued since publicationAmd. No. Date CommentsTECHNICAL SPECIFICATIONSPCIFICATION TECHNIQUETECHNISCHE SPEZIFIKATIONCEN/TS 15568December 2006ICS 67.050English VersionFoodstuffs - Methods of analysis for th
9、e detection of geneticallymodified organisms and derived products - Sampling strategiesProduits alimentaires - Mthodes danalyse pour ladtection des organismes gntiquement modifis et desproduits drivs - Stratgies dchantillonnageLebensmittel - Verfahren zum Nachweis von gentechnischmodifizierten Organ
10、ismen und ihren Produkten -ProbenahmestrategienThis Technical Specification (CEN/TS) was approved by CEN on 7 November 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 will be requested to submit theircomme
11、nts, 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 appropriate form. It is permissible to keep c
12、onflicting 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, Finland, France,Germany, Greece, H
13、ungary, 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 KOMITEE FR NORMUNGManagement Centre:
14、 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/TS 15568:2006: E2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle6 5 Apparat
15、us and equipment 7 6 Sampling of non-packed food products7 7 Sampling of pre-packed units 9 8 Preparation of the analytical sample and the test portion 10 9 Packaging and labelling of laboratory samples .10 10 Dispatch of laboratory samples .11 11 Sampling report .11 Annex A (informative) Laboratory
16、 sample sizes of different cereals and oilseeds13 Annex B (informative) Sampling scheme for consignments of more than 100 bags according to ISO 1369014 Annex C (informative) Estimation of the number of particles in 100 mg test portions after ultra-centrifugal milling15 Bibliography 16 CEN/TS 15568:2
17、0063 Foreword This document (CEN/TS 15568:2006) has been prepared by Technical Committee CEN/TC 275 “Food analysis - Horizontal methods”, the secretariat of which is held by DIN. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN
18、 and/or CENELEC shall not be held responsible for identifying any or all such patent rights. NOTE This document has been submitted to the Enquiry under reference number prEN 21568. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are
19、bound to announce this 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, Slovenia, Spain, Sweden, Swi
20、tzerland and the United Kingdom. CEN/TS 15568:20064 Introduction Correct sampling is an operation that requires the most careful attention. Emphasis should be laid on the necessity of obtaining a representative sample of the goods under investigation. If ad-hoc sampling of food products is undertake
21、n without applying a sampling strategy and without considering the lot specific properties, the analytical result is only valid for the sample that has been analysed. It is not possible to extend the result to the rest of the lot. By applying sampling strategies to assess the level of compliance of
22、a given lot of products, a certain number of samples is taken, and the result of the analysis can be extended to the whole lot. The use of sampling strategies is the only effective way to make correct statements about the nature, in this case the GMO-content, of the product tested. This Technical Sp
23、ecification has been established for food products, but could also be applied to other products, e.g. animal feed and plant samples from the environment. NOTE In certain areas there are widely recognised trade associations which specify rules for the sampling strategies to be used in contracts under
24、 their auspices. In no case will this Technical Specification override the rules laid down in such contracts. CEN/TS 15568:20065 1 Scope This Technical Specification gives guidance for setting up valid sampling strategies for food products that are to be analysed for the presence of genetically modi
25、fied organisms and derived 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 undated references, the latest edition of the referenced document (including any amendments
26、) applies. EN ISO 21569, Foodstuffs Methods of analysis for the detection of genetically modified organisms and derived products Qualitative nucleic acid based methods (ISO 21569:2005) EN ISO 21570, Foodstuffs Methods of analysis for the detection of genetically modified organisms and derived produc
27、ts Quantitative nucleic acid based methods (ISO 21570:2005) EN ISO 21571, Foodstuffs Methods of analysis for the detection of genetically modified organisms and derived products Nucleic acid extraction (ISO 21571:2005) EN ISO 21572, Foodstuffs Methods for the detection of genetically modified organi
28、sms and derived products Protein based methods (ISO 21572:2004) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Consignment quantity of some commodity delivered at one time and covered by one set of documents. The consignment may consist of o
29、ne or more lots or part(s) of lots ISO 7002:1986 3.2 Lot stated portion of the consignment to be tested for presence of GMO 3.3 Increment quantity of material taken at one time from a larger body of material NOTE Increments may be tested individually aiming at estimation of the variation of any char
30、acteristic throughout a lot (or between lots). ISO 7002:1986 3.4 Item actual or conventional object (a defined quantity) on which a set of observations may be made ISO 7002:1986 3.5 Sample one or more items (or a portion of material) selected in a prescribed or systematic manner from a lot NOTE It i
31、s intended to provide information representative of the lot, and, possibly, to serve as a basis for decision on the lot. CEN/TS 15568:20066 3.6 File increment sample increment that is retained for a specific period of time for further analysis 3.7 Bulk sample composite of the increments taken from a
32、 lot 3.8 Laboratory sample sample as prepared for sending to the laboratory and intended for inspection or testing ISO 7002:1986 3.9 Test portion sample, as prepared for testing or analysis, the whole quantity being used for analysis or testing at one time ISO 3534-1:2006 3.10 Lot size number of ite
33、ms or quantity of material constituting the lot ISO 7002:1986 3.11 Sample size number of items or quantity of material constituting the sample ISO 7002:1986 3.12 Sample division process of selecting one or more representative sub-samples from a sample by such means as riffling or mechanical dividing
34、 3.13 Sampling uncertainty part of the total estimation uncertainty due to one or several of the following: - the failing of a sample to accurately represent the lot; - the random nature of sampling; - the known and accepted characteristics of the sampling strategy 3.14 Sampling strategy predetermin
35、ed procedure for the selection, withdrawal and preparation of samples from a lot to yield the required information so that a decision can be made regarding the acceptance of the lot ISO 7002:1986 4 Principle In this Technical Specification sampling is considered to consist of the following steps: co
36、llection of a sufficient number of increments from a lot to form the bulk sample; reduction of the bulk sample to the laboratory sample; grinding the laboratory sample to the appropriate particle size and homogenisation. CEN/TS 15568:20067 Samples shall be representative of the lots from which they
37、are taken. Therefore, as the composition of a lot is seldom uniform, a sufficient number of increments shall be taken and carefully mixed, thus giving a bulk sample from which the laboratory sample is obtained by successive divisions or otherwise. If it is necessary to determine the sampling uncerta
38、inty, file increment samples should be kept for further analysis. Appropriate measures shall be taken to avoid any alteration in the composition of the samples. 5 Apparatus and equipment Many different types of sampling instruments or equipment are available. Equipment should be chosen as appropriat
39、e for the food products to be sampled and the quantity and containers involved. Examples of sampling instruments are given in e.g. ISO 13690 and ISO 6644. Special care is necessary to ensure that all sampling apparatus is clean to avoid contamination of the material under investigation. Sampling sha
40、ll be carried out in such a manner as to protect the samples, the sampling instruments and the container in which the samples are placed, from adventitious contamination. Special attention shall be paid to avoid cross-contamination during the sampling procedure between different lots. Material adher
41、ing to the outside of the sampling instrument shall be removed before the contents are discharged. 6 Sampling of non-packed food products 6.1 Statistical principles Lot distribution properties affect the efficiency of sampling strategies 5. Where the variable of interest is randomly distributed with
42、in the lot under investigation, the sampling uncertainty can be estimated according to the binomial distribution 6. However, in reality, non-packed food product lots may show non-random distributions 7, and lot heterogeneity should be taken into account when defining sampling procedures statisticall
43、y. This sampling protocol provides a way of estimating the sampling uncertainty associated with the overall GMO content of a lot without imposing any distribution assumption. The Standard Deviation (SD) of the increment GMO content estimates may be interpreted as an indicator of the lot heterogeneit
44、y and in highly heterogeneous lots as an indication of the sampling uncertainty. Generally, the larger the standard deviation, the larger is the sampling uncertainty in highly heterogeneous lots. 6.2 Procedure 6.2.1 General This protocol is designed to provide an estimate of the GMO content of the l
45、ot based on a bulk sample. If an estimate of the sampling uncertainty is required, 6.2.3 describes a procedure to determine it. 6.2.2 Sampling of increments Lots should be sampled following the technical principles given in ISO 6644 as described in 6.3 and ISO 13690 as described in 6.4. The number o
46、f sampling points, where the increments for creating the bulk sample and the file increment samples are taken is defined according to the lot size. In case of lots from 50 t to 500 t, the size of the bulk sample should be 0,01 % of the total lot size. In case of lots smaller than 50 t, the size of t
47、he bulk sample should be 5 kg. In case of lots larger than 500 t, the size of the bulk sample should be 50 kg (see Table 1). CEN/TS 15568:20068 Table 1 Number of sampling points according to the lot size Lot size t Size of the bulk sample kg Number of sampling points 50 5 10 50 to 500 0,01% of lot s
48、ize 2 times bulk sample size in kg 500 50 100 The bulk sample shall be formed by combining the increments and mixing them thoroughly. Large sampling units e.g. potatoes, squash, coconuts, sugar beets, papaya should be sampled according to Clause 7. A laboratory sample is prepared from the bulk sampl
49、e by using sample dividers as described in ISO 13690. The analyses shall be carried out according to EN ISO 21571, EN ISO 21569, EN ISO 21570 and/or EN ISO 21572. If it is considered necessary to calculate the sampling uncertainty on an individual lot basis, an estimation of the sampling uncertainty may be carried out as described in 6.2.3. 6.2.3 Determination of sampling uncertainty At each sampling interval (systematic sampling) or sampling point (static sampling) an increment of 1 kg should be collected, mixed thor
