1、BSI Standards PublicationBS EN ISO 6885:2016Animal and vegetable fatsand oils Determination ofanisidine valueBS EN ISO 6885:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 6885:2016. It supersedes BS EN ISO 6885:2007 which is withdrawn.The UK participat
2、ion in its preparation was entrusted to Technical Committee AW/307, Oilseeds, animal and vegetable fats and oils and their by-products.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 necessary prov
3、isions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016ISBN 978 0 580 91531 4 ICS 67.200.10 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was publ
4、ished under the authority of the Standards Policy and Strategy Committee on 31 March 2016.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORMEN ISO 6885 March 2016 ICS 67.200.10 Supersedes EN ISO 6885:2007English Version Animal and vegetable fats an
5、d oils - Determination of anisidine value (ISO 6885:2016) Corps gras dorigines animale et vgtale - Dtermination de lindice danisidine (ISO 6885:2016)Tierische und pflanzliche Fette und le - Bestimmung der Anisidinzahl (ISO 6885:2016) This European Standard was approved by CEN on 30 January 2016. CEN
6、 members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate 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 appl
7、ication to the CEN-CENELEC Management Centre or to any CEN member. This European Standard 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 Ma
8、nagement Centre has the same status as the official versions. CEN members are the national 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, Lat
9、via, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marn
10、ix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6885:2016 EBS EN ISO 6885:2016EN ISO 6885:2016 (E) 3 European foreword This document (EN ISO 6885:2016) has been prepared by Technical Committee ISO/TC
11、 34 “Foodproducts” in collaboration with Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fatsand oils and their by-products - Methods of sampling and analysis” the secretariat of which is held byAFNOR. This European Standard shall be given the status of a national standard, either by
12、publication of anidentical text or by endorsement, at the latest by September 2016, and conflicting national standardsshall be withdrawn at the latest by September 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject ofpatent rights. CEN and/or CE
13、NELEC shall not be held responsible for identifying any or all such patentrights. This document supersedes EN ISO 6885:2007. According to the CEN-CENELEC Internal Regulations, the national standards organizations of thefollowing countries are bound to implement this European Standard: Austria, Belgi
14、um, 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, Slovakia, Slovenia, Spain, Sweden, Switzerlan
15、d,Turkey and the United Kingdom. Endorsement notice The text of ISO 6885:2016 has been approved by CEN as EN ISO 6885:2016 without any modification. BS EN ISO 6885:2016ISO 6885:2016(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents 16 Apparatus . 27 S
16、ampling 28 Preparation of test sample . 29 Procedure. 39.1 Test portion and preparation of test solution 39.2 Unreacted test solution 39.3 Reacted test solution 39.4 Blank 39.5 Spectrometric measurement 39.6 Absorbance range . 310 Expression of results 411 Precision . 411.1 Interlaboratory tests 411
17、.2 Repeatability . 411.3 Reproducibility . 412 Test report . 5Annex A (informative) Results of the interlaboratory test 6Bibliography 7 ISO 2016 All rights reserved iiiContents PageBS EN ISO 6885:2016ISO 6885:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide fede
18、ration 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 right to be represented on that commi
19、ttee. 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 procedures used to develop this document and
20、 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 rules of the ISO/IEC Directives, Part
21、 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 identified during the development of the
22、 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 explanation on the meaning of ISO specific terms
23、 and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 34, Food products, Subcommitt
24、ee SC 11, Animal and vegetable fats and oils.This fourth edition cancels and replaces the third edition (ISO 6885:2006), which has been technically revised by adding a sentence to the Scope and deleting a column in Table A.1.iv ISO 2016 All rights reservedBS EN ISO 6885:2016INTERNATIONAL STANDARD IS
25、O 6885:2016(E)Animal and vegetable fats and oils Determination of anisidine value1 ScopeThis International Standard specifies a method for the determination of the anisidine value in animal and vegetable fats and oils. This is a measure of the amount of aldehydes present (principally , -unsaturated
26、aldehydes).Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this International Standard.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For date
27、d references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 661, Animal and vegetable fats and oils Preparation of test sampleISO 3696, Water for analytical laboratory use Specification and test methods3 T
28、erms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1anisidine valueone hundred times the increase in absorbance, measured at a wavelength of 350 nm in a 10 mm cell, of a test solution when reacted with p-anisidine under the test conditions specified in
29、 this International StandardNote 1 to entry: The anisidine value has no dimensions, and is calculated and quoted on the basis of 1 g of the test sample in 100 ml of a mixture of solvent and reagent.4 PrincipleA test solution is prepared in isooctane (2,2,4-trimethylpentane). It is reacted with an ac
30、etic acid solution of p-anisidine. The increase in absorbance at 350 nm is measured. The anisidine value is calculated.5 ReagentsUse only reagents of recognized analytical grade, and water complying with grade 3 of ISO 3696.5.1 Sodium sulfate (Na2SO4), anhydrous.5.2 Isooctane (2,2,4-trimethylpentane
31、), having an absorbance not exceeding 0,01 against water in the wavelength range 300 nm to 380 nm.5.3 4-Methoxyaniline (p-anisidine), anhydrous cream-coloured crystals.WARNING p-anisidine is toxic and care shall be taken to avoid contact with the skin. ISO 2016 All rights reserved 1BS EN ISO 6885:20
32、16ISO 6885:2016(E)Store the p-anisidine in a dark bottle at 0 C to 4 C in the dark.No coloration (grey or pink) shall be observed. If this is present, purify the p-anisidine as follows.Dissolve 4 g of p-anisidine in 100 ml of water at 75 C. Add 0,5 g of sodium sulfite (Na2SO3) and 2 g of charcoal. S
33、tir for 5 min and filter through a medium retention filter paper to give a clear solution. Cool the filtrate to 0 C and leave at this temperature for at least 4 h. Filter off the crystals, preferably under vacuum, and wash with a small volume of water at about 0 C. Dry in a vacuum desiccator contain
34、ing an efficient desiccant.5.4 Glacial acetic acid, of water content not greater than 0,1 % (mass fraction).5.5 Anisidine reagent.On the day of use, prepare the minimum quantity of reagent required for the analysis, in view of its toxicity and limited life. Prepare, for example, 50 ml of reagent as
35、follows.Dissolve 0,125 g of the p-anisidine (5.3) in the glacial acetic acid (5.4) in a 50 ml volumetric flask and dilute to the mark with the same solvent, avoiding exposure to strong light.Check the absorbance against isooctane before use and discard the reagent when the difference is larger than
36、0,2. In any case, discard any reagent left over on the day of use.6 ApparatusUsual laboratory apparatus and, in particular, the following.6.1 Spectrometer, double- or single-beam, suitable for use at a wavelength of 350 nm, with cells of optical path length 10 mm.When a double-beam spectrometer is u
37、sed, it is recommended that a pair of matched 10 mm cells be used.6.2 Volumetric flasks, of 25 ml capacity.6.3 Test tubes, of 10 ml capacity, fitted with ground glass stoppers.6.4 Pipettes, of 1 ml and 5 ml capacities, equipped with a safety suction device.7 SamplingA representative sample should ha
38、ve been sent to the laboratory. It should not have been damaged or changed during transport or storage.Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 5555.8 Preparation of test samplePrepare the test sample in accordance wit
39、h ISO 661.If the moisture content of the sample is greater than 0,10 % (mass fraction), it should be dried using the following procedure.Add sodium sulfate (5.1) in the proportion of 1 g to 2 g per 10 g of the thoroughly mixed sample, at a temperature of not more than 10 C above the melting point in
40、 the case of a solid fat. Stir thoroughly and filter, maintaining the temperature to prevent solidification.2 ISO 2016 All rights reservedBS EN ISO 6885:2016ISO 6885:2016(E)Take care to exclude extraneous moisture during the procedure because it can affect the equilibrium reaction during which water
41、 is produced.9 Procedure9.1 Test portion and preparation of test solutionWeigh, to the nearest 1 mg, a sufficient mass of the prepared test sample (Clause 8) directly into a 25 ml volumetric flask. Preheat solid samples to 10 C above their melting point. Dissolve the sample in 5 ml to 10 ml of the i
42、sooctane (5.2) and make up to the mark with the same solvent.The size of the test portion depends on the quality of the sample and the characteristics of the spectrometer used, and should be chosen to avoid readings near the upper and lower ends of the scale. In general, 0,4 g to 4,0 g is used.9.2 U
43、nreacted test solutionBy means of a pipette (6.4), transfer 5 ml of the test solution (9.1) to a test tube (6.3). Add 1 ml of glacial acetic acid (5.4), stopper the tube and shake well. Keep the test tube in the dark at (23 3) C for 8 min.Within a further 2 min, transfer the solutions to a clean, dr
44、y spectrometer cell. After a total reaction time of 10 min 1 min, follow the procedure specified in 9.5.9.3 Reacted test solutionTransfer, by means of a pipette (6.4), 5 ml of the test solution (9.1) to a test tube (6.3). Add, by means of a pipette (6.4), 1 ml of the anisidine reagent (5.5). Stopper
45、 the tube and shake well. Keep the test tube in the dark at (23 3) C for 8 min.Within a further 2 min, transfer the solutions to a clean, dry spectrometer cell. After a total reaction time of 10 min 1 min from the addition of the anisidine reagent, follow the procedure specified in 9.5.9.4 BlankTran
46、sfer, by means of a pipette (6.4), 5 ml of isooctane (5.2) to a test tube (6.3). Add, by means of a pipette (6.4), 1 ml of the anisidine reagent (5.5). Stopper the tube and shake well. Keep the test tube in the dark at (23 3) C for 8 min.Within a further 2 min, transfer the solutions to a clean, dry
47、 spectrometer cell. After a total reaction time of 10 min 1 min from the addition of the anisidine reagent, follow the procedure specified in 9.5.9.5 Spectrometric measurementAdjust the zero absorption of the spectrometer with isooctane (5.2) at 350 nm.Measure the following absorbances against isooc
48、tane (5.2): A1of the reacted solution (9.3), A0of the unreacted test solution (9.2), and A2of the blank (9.4).9.6 Absorbance rangeIf the measured absorbance A1of the reacted solution (9.3) is not in the range 0,2 to 0,8, repeat the determination (9.2 to 9.4) with an adjusted amount of test sample. I
49、SO 2016 All rights reserved 3BS EN ISO 6885:2016ISO 6885:2016(E)If the measured absorbance A2of the blank exceeds 0,2, purify the anisidine reagent as described in 5.3, and prepare fresh anisidine reagent (5.5). Repeat this test with the fresh anisidine reagent.10 Expression of results10.1 The anisidine value (AV) of the sample is equal to Formula (1):AV =)20100121QVmAAA,( (1)whereV is the volume in which the test sample is dissolved, in millilitres (V = 25 ml);m is the mass of the test portion, in grams;Q is the samp
