1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Cheese, cheese rind and processed cheese - Determination of natamycin contentPart 2: High-performance liquid chromatographic method for cheese, cheese rind and processed cheeseBS EN ISO 9233-2:2018National forewordThis
2、British Standard is the UK implementation of EN ISO 9233-2:2018. It is identical to ISO 9233-2:2018. It supersedes BS EN ISO 9233-2:2013, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/5, Chemical analysis of milk and milk products.A list of organi
3、zations represented on this committee 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 correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018
4、ISBN 978 0 580 51672 6ICS 67.100.30Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2018.Amendments/corrigenda issued since publicationDate Text affectedBR
5、ITISH STANDARDBS EN ISO 9233-2:2018EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 9233-2May 2018ICS 67.100.30 Supersedes EN ISO 9233-2:2013EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCEN-CENELEC Management Centre: Avenue Marnix 17, B-1000
6、Brussels 2018 CEN Ref. No. EN ISO 9233-2:2018: EAll rights of exploitation in any form and by any means reserved worldwide for CEN national MembersCheese, cheese rind and processed cheese - Determination of natamycin content - Part 2: High-performance liquid chromatographic method for cheese, cheese
7、 rind and processed cheese (ISO 9233-2:2018)Fromage, crote de fromage et fromages fondus - Dtermination de la teneur en natamycine - Partie 2: Mthode par chromatographie liquide haute performance pour fromage, crote de fromage et fromages fondus (ISO 9233-2:2018)Kse, Kserinde und Schmelzkse - Bestim
8、mung des Natamycingehalts - Teil 2: Verfahren mit Hochleistungs-Flssigchromatographie fr Kse, Kserinde und Schmelzkse (ISO 9233-2:2018)This European Standard was approved by CEN on 4 April 2018.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions f
9、or 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 to the CEN-CENELEC Management Centre or to any CEN member.This European Standard exists in thre
10、e 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-CENELEC Management Centre has the same status as the official versions.CEN members are the national standards bodi
11、es of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slov
12、enia, Spain, Sweden, Switzerland, Turkey and United Kingdom.English VersionEN ISO 9233-2:2018 (E)European forewordThis document (EN ISO 9233-2:2018) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 302 “Milk and milk products - Metho
13、ds 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 November 2018, and conflicting national standards shall be withdrawn at the lat
14、est by November 2018.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.This document supersedes EN ISO 9233-2:2013.According to the CEN-CENELEC Internal
15、 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Irela
16、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.Endorsement noticeThe text of ISO 9233-2:2018 has been approved by CEN as EN ISO 9233-2:2018 without any modification
17、.2BS EN ISO 9233-2:2018ISO 9233-2:2018Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents 26 Apparatus . 27 Sampling 38 Preparation of test sample . 38.1 Cheese rind . 38.2 Cheese interior and processed cheese . 39 Procedure. 49.1 Test portion 49.1.1 Chee
18、se rind . 49.1.2 Cheese interior and processed cheese 49.2 Preparation of test solution . 49.2.1 Cheese rind . 49.2.2 Cheese interior and processed cheese 49.3 Determination . 59.3.1 Determination and detection limits 59.3.2 Adjustment of the liquid chromatograph (6.14) 59.3.3 Calibration graph . 59
19、.3.4 Test solution. 59.3.5 Low natamycin content 610 Calculation and expression of results . 610.1 Calculation of natamycin mass fraction . 610.2 Calculation of surface-area-related natamycin mass . 710.3 Correction of results . 710.4 Expression of results 711 Precision . 711.1 Interlaboratory tests
20、 711.2 Repeatability . 711.3 Reproducibility . 712 Test report . 7Annex A (informative) Examples 9Annex B (informative) Results of interlaboratory trial 11Bibliography .12 ISO 2018 All rights reserved iiiContents PageBS EN ISO 9233-2:2018ISO 9233-2:2018ForewordISO (the International Organization for
21、 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 committees. Each member body interested in a subject for which a technical committee has been established has the
22、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 International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The proced
23、ures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial
24、 rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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. Details of any patent rights id
25、entified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanati
26、on on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/fo
27、reword.html.This document 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 jointly by ISO and IDF.This second edition cancels and replaces the first edition (ISO 9233-2 | IDF 14
28、0-2:2007), of which it constitutes a minor revision to incorporate the amendment ISO 9233-2:2007/Amd.1:2012.A list of all parts in the ISO 9233 | IDF 140 series can be found on the ISO website.iv ISO 2018 All rights reservedBS EN ISO 9233-2:2018ISO 9233-2:2018IDF (the International Dairy Federation)
29、 is a non-profit private sector organization representing the interests of various stakeholders in dairying at the global level. IDF members are organized in National Committees, which are national associations composed of representatives of dairy-related national interest groups including dairy far
30、mers, dairy processing industry, dairy suppliers, academics and governments/food control authorities. ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International
31、 Standards using the logos and reference numbers of both organizations.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. Details of any patent rights i
32、dentified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.This document wa
33、s prepared by the IDF Standing Committee on Analytical methods for additives and contaminants and ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published jointly by ISO and IDF.The work was carried out by the Joint ISO/IDF Action Team on Sel
34、ected food additives and vitamins of the Standing Committee on Analytical methods for additives and contaminants under the aegis of its project leader, Mr. M. Carl (DE). ISO 2018 All rights reserved vBS EN ISO 9233-2:2018This page deliberately left blankCheese, cheese rind and processed cheese - Det
35、ermination of natamycin content Part 2: High-performance liquid chromatographic method for cheese, cheese rind and processed cheese1 ScopeThis document specifies a method for the determination of natamycin mass fraction in cheese, cheese rind and processed cheese of above 0,5 mg/kg and of the surfac
36、e-area-related natamycin mass in cheese rind of above 0,03 mg/dm2.2 Normative referencesThere are no normative references in this document.3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in stan
37、dardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at https:/www.iso.org/obp3.1natamycin contentmass fraction of substances determined by the procedure specified in this documentNote 1 to entry: The natamycin con
38、tent is expressed in milligrams per kilogram.3.2surface-area-related natamycin mass in cheese rindsurface-area-related mass of substances determined by the procedure specified in this documentNote 1 to entry: The surface-area-related natamycin mass is expressed in milligrams of natamycin per square
39、decimetre of cheese rind.3.3cheese rindouter layer of the cheese, excluding the coating layer, if present4 PrincipleA known quantity of sample is extracted with methanol. The extract is diluted with water followed by cooling to between 15 C and 20 C to precipitate most of the fat, followed by filtra
40、tion. The natamycin content or surface-area-related natamycin mass is determined in the filtrate (after concentration, if necessary) by high-performance liquid chromatography (HPLC).INTERNATIONAL STANDARDISO 9233-2:2018(E) ISO and IDF 2018 All rights reserved 1BS EN ISO 9233-2:2018ISO 9233-2:2018(E)
41、5 ReagentsUse only reagents of recognized analytical grade, unless otherwise specified, and only distilled or demineralized water or water of equivalent purity.5.1 Methanol (CH3OH).5.2 Methanol, aqueous solution.Mix two volumes of methanol (5.1) with one volume of water.5.3 Natamycin standard stock
42、solution, of concentration 500 mg/l.Immediately before use, dissolve in methanol (5.1) a quantity of a natamycin preparation of known natamycin content, corresponding to 50 mg of pure natamycin (C33H47NO13), in a 100 ml one-mark volumetric flask (6.1). Make up to the mark with water and mix.5.4 Nata
43、mycin standard working solution, of concentration 5 mg/l.Pipette 5,0 ml of the natamycin standard stock solution (5.3) in a 50 ml one-mark volumetric flask (6.1). Dilute to the mark with aqueous methanol (5.2) and mix.Pipette 5,0 ml of the thus diluted solution into another 50 ml one-mark volumetric
44、 flask (6.1). Dilute to the mark with aqueous methanol (5.2) and mix. The concentration of this natamycin standard working solution is 5 g/ml.This concentration shall be close to that of the test solution measured in 9.3.3. Adjust the standard working dilution by pipetting and diluting another quant
45、ity, if required.5.5 Acetic acid (CH3CO2H), glacial.6 ApparatusUsual laboratory equipment and, in particular, the following.6.1 One-mark volumetric flasks, of capacities 50 ml and 100 ml.6.2 Slicer or similar apparatus, capable of cutting cheese portions of thickness 5 mm and of width about 30 mm (F
46、igure A.1 shows an example).6.3 Fine slicer, capable of cutting thin cheese slices of maximum thickness 1 mm (Figure A.2 shows an example).6.4 Grinder or blender.6.5 Sharp knife, capable of cutting cheese slices into small pieces.6.6 Magnetic stirrer or shaking machine.6.7 Conical flasks, of capacit
47、ies 100 ml and 200 ml, made of coloured glass and fitted with ground-glass stoppers.6.8 Syringes, disposable, of capacity 10 ml.6.9 Membrane microfilters, of pore size 0,20 m and 0,45 m, resistant to attack by alcoholic solutions.2 ISO and IDF 2018 All rights reservedBS EN ISO 9233-2:2018ISO 9233-2:
48、2018(E)6.10 Folded paper filters, fast speed, of diameter 150 mm. (e.g. S and S, No. 595 1/21).6.11 Funnel, of diameter approximately 70 mm.6.12 Freezer, capable of freezing at a temperature of between 15 C and 20 C.6.13 Extraction cartridges, to concentrate the filtered extract, if necessary (e.g.
49、Sep-pack C181)or Waters No. 519101).6.14 Liquid chromatograph, with UV detector, capable of measuring at 303 nm and equipped with a recorder and/or integrator.6.15 Analytical column, of length 150 mm, of internal diameter 4,6 mm, type C8, having a particle size of 5 m (e.g. Lichrosorb RP81).6.16 Guard column, of length 100 mm, of internal diameter 2,1 mm, type C8, having a particle size of 30 m to 40 m (e.g. Perisorb RP81).6.17 Sample jar, of suitable capacity.7 SamplingA representative sample should be sent to the laboratory. It
