1、May 2017 English price group 11No 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).ICS 67.200.10!%dy“2659686www.din.deDIN E
2、N ISO 8534Animal and vegetable fats and oils Determination of water content Karl Fischer method (pyridine free) (ISO 8534:2017);English version EN ISO 8534:2017,English translation of DIN EN ISO 8534:2017-05Tierische und pflanzliche Fette und le Bestimmung des Wassergehalts KarlFischerVerfahren (pyr
3、idinfrei) (ISO 8534:2017);Englische Fassung EN ISO 8534:2017,Englische bersetzung von DIN EN ISO 8534:2017-05Corps gras dorigines animale et vgtale Dtermination de la teneur en eau Mthode de Karl Fischer (sans pyridine) (ISO 8534:2017);Version anglaise EN ISO 8534:2017,Traduction anglaise de DIN EN
4、ISO 8534:2017-05SupersedesDIN EN ISO 8534:200810www.beuth.deDocument comprises 19 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.05.17 DIN EN ISO 8534:2017-05 2 A comma is used as the decimal marker. National foreword This doc
5、ument (EN ISO 8534:2017) has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France) in collaboration with Technical Committee CEN/TC 307 “Oil seeds, vegetable and animal fats and oils and their by-products Methods of sampling and analysis” (Secretariat: AFNOR, Fr
6、ance). The responsible German bodies involved in its preparation were DIN-Normenausschuss Lebensmittel und landwirtschaftliche Produkte (DIN Standards Committee Food and Agricultural Products) and the Deutsche Gesellschaft fr Fettwissenschaft (German Fat Research Society), Joint Working Committee NA
7、 057-05-05 AA “Joint committee of DIN and DGF for the analysis of fats, oils and products thereof, related and primary products”. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 661 DIN EN ISO 661 ISO 5555 DIN EN ISO 5555 ISO 5725-1 DIN
8、 ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO/IEC 17025 DIN EN ISO/IEC 17025 Amendments This standard differs from DIN EN ISO 8534:2008-10 as follows: a) milk and milk products (or fat coming from milk and milk products) are now excluded from the scope of the standard; b) the standard has been editorial
9、ly revised and brought in line with the current rules of presentation. Previous editions DIN EN ISO 8534: 2008-10 DIN EN ISO 8534:2017-05 3 National Annex NA (informative) Bibliography DIN EN ISO 661, Animal and vegetable fats and oils Preparation of test sample DIN EN ISO 5555, Animal and vegetable
10、 fats and oils Sampling DIN EN ISO/IEC 17025:2005-08, General requirements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions DIN ISO 5725-2, A
11、ccuracy (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 8534:2017-05 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 853
12、4 February 2017 ICS 67.200.10 Supersedes EN ISO 8534:2008English Version Animal and vegetable fats and oils - Determination of water content - Karl Fischer method (pyridine free)(ISO 8534:2017) Corps gras d origines animale et vgtale - Dtermination de la teneur en eau - Mthode de Karl Fischer (sans
13、pyridine) (ISO 8534:2017) Tierische und pflanzliche Fette und le - Bestimmung des Wassergehalts - Karl-Fischer-Verfahren (pyridinfrei) (ISO 8534:2017) This European Standard was approved by CEN on 8 February 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipul
14、ate the conditions for 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 St
15、andard exists in three 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 n
16、ational standards bodies 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,
17、Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and
18、 by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8534:2017 EForeword .4Introduction . 51 Scope . 62 Normative references 63 Terms and definitions . 64 Principle 65 Reagents 66 Apparatus . 77 Sampling 78 Preparation of the test sample . 79 Procedure. 89.1 Titre 89.2 Test por
19、tion 99.3 Determination 1010 Expression of results .1011 Precision of the method .1111.1 Interlaboratory test1111.2 Repeatability 1111.3 Reproducibility 1112 Test report 11Annex A (informative) Results of interlaboratory tests.12Annex B (informative) Information and precision data on the use of the
20、coulometric method .13Bibliography .15Contents PageEN ISO 8534:2017 (E) DIN EN ISO 8534:2017-05 2European foreword . 3European foreword This document (EN ISO 8534:2017) has been prepared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 307 “Oilseeds,
21、vegetable and animal fats and oils and their by-products - Methods of sampling and analysis” the secretariat of which is held by AFNOR. 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 August 2017,
22、 and conflicting national standards shall be withdrawn at the latest by August 2017. 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 rights. T
23、his document supersedes EN ISO 8534:2008. 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, Former Y
24、ugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 85
25、34:2017 has been approved by CEN as EN ISO 8534:2017 without any modification. EN ISO 8534:2017 (E) DIN EN ISO 8534:2017-05 3 ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Internation
26、al 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, in liaison with ISO,
27、 also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part
28、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 rules of the ISO/IEC Directives, Part 2 (see www. iso. org/ directives).Attention is drawn to the possibility that some of the
29、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 identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations rec
30、eived (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 explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs
31、 adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso. org/ iso/ foreword. html.This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils.This third
32、 edition cancels and replaces the second edition (ISO 8534:2008), of which it constitutes a minor revision to exclude the applicability for fat coming from milk and milk products.EN ISO 8534:2017 (E) DIN EN ISO 8534:2017-05 4 IntroductionThe determination of the water content of fats and oils accord
33、ing to Karl Fischer is carried out by two different procedures. This document specifies the volumetric Karl Fischer method for the determination of higher milligram levels of water (high level moisture). It is used for samples having between 1 mg and 100 mg of water in the sample.Annex B specifies a
34、 coulometric titration, which requires between 10 g and 10 mg water in the sample. The coulometric method is more sensitive than the volumetric method and permits the determination of lower water contents.EN ISO 8534:2017 (E) DIN EN ISO 8534:2017-05 5 1 ScopeThis document specifies a method for the
35、determination of the water content of animal and vegetable fats and oils (hereinafter referred to as fats) using Karl Fischer apparatus and a reagent which is free of pyridine.Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this document.2 Normative
36、referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendmen
37、ts) applies.ISO 661, Animal and vegetable fats and oils Preparation of test sample3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia:
38、 available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp3.1water contentmass, in grams per 100 g of sample, of water as determined in accordance with the method specified in this documentNote 1 to entry: The water content is expressed
39、as a percentage mass fraction.4 PrincipleDissolved fat is titrated against an iodine solution and sulfur dioxide (SO2) is oxidized by iodine in the presence of water. In principle, the chemical reaction in Formula (1) takes place:HO ISOCHOHRNRNH SO CH RNHI22 23 4332+ +(1)The alcohol reacts with SO2a
40、nd a nitrogenous base (RN) to form an intermediate alkylsulfite salt, which is then oxidized by iodine to an alkylsulfate salt. This oxidation reaction consumes water contained in the sample. The end point is monitored potentiometrically.5 ReagentsWARNING Comply with any local regulations which spec
41、ify the handling of hazardous substances. Technical, organizational and personal safety measures shall be followed.EN ISO 8534:2017 (E) DIN EN ISO 8534:2017-05 6 It is recommended that “ready for use” working solvents be used, either one-component reagents (5.1.1) or two-component reagents (5.1.2).
42、Reagents with a titre of 1 mg and 2 mg water per millilitre are required for acceptable performance.5.1 Karl Fischer reagents, consist of one-component reagents or two-component reagents for volumetric determination.5.1.1 One-component reagents, contain all the reactant in the titrant solution: iodi
43、ne, sulfur dioxide, and imidazole, dissolved in a suitable alcohol. Methanol is typically used as the working medium in the titration cell.Absolute methanol is the solvent of choice. But for fats and oils, use a mixture of absolute methanol and absolute chloroform (the methanol content should be at
44、least 25 % volume fraction, or optimally 50 % volume fraction).5.1.2 Two-component reagents, consist of all necessary reactants for the titration, but in two different solutions. The titrating agent (usually known as the titrant) contains only iodine and methanol, while the solvent containing the ot
45、her Karl Fischer reaction components is used as the working medium in the titration cell.5.2 Water standard, commercially prepared standard with a certified concentration of 10 mg/g (1,0 % mass fraction).6 ApparatusUsual laboratory apparatus and, in particular the following.6.1 Karl Fischer apparatu
46、s, set up according to the manufacturers recommendations for the determination of water in fats and oils. Set up and conduct protocols for routine maintenance as recommended by the manufacturer. Use an airtight vessel and do not place the instrument in high humidity areas. Do not place instruments o
47、r handle samples near water sources, such as taps, sinks, and dishwashers in the laboratory.6.2 Analytical balance, readable to the nearest 0,1 mg.6.3 Syringes, of capacity 1 ml, 2 ml, 5 ml, 10 ml, and 20 ml.To ensure accurate and reproducible results from the water standard, use a glass gastight sy
48、ringe. For water standard 10,0, use a 10 ml syringe and for either the water standard 1,00 or 0,10, use a 5 ml syringe. In addition to the appropriate size syringe, use a needle that is long enough to allow for a subsurface injection when injecting through the instruments septum.7 SamplingA representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage.Samplin
