1、BS EN ISO 15774:2017Animal and vegetable fatsand oils Determination ofcadmium content by directgraphite furnace atomicabsorption spectrometry (ISO15774:2017)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 15774:2017 BRITISH STANDARDNational forewordThis Bri
2、tish Standard is the UK implementation of EN ISO 15774:2017. It supersedes BS EN ISO 15774:2001 which iswithdrawn.The UK participation 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 represente
3、d 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 2017.Published by BSI Standards Limited 2017ISBN 978 0 580 944
4、09 3 ICS 67.200.10 Compliance 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 28 February 2017.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUR
5、OPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15774 February 2017 ICS 67.200.10 Supersedes EN ISO 15774:2001English Version Animal and vegetable fats and oils - Determination of cadmium content by direct graphite furnace atomic absorption spectrometry (ISO 15774:2017) Corps gras dorigines an
6、imale et vgtale - Dtermination de la teneur en cadmium par spectromtrie dabsorption atomique four graphite (ISO 15774:2017) Tierische und pflanzliche Fette und le - Bestimmung von Cadmium mit Direkt-Graphitofen-Atomabsorptionsspektrometrie (ISO 15774:2017) This European Standard was approved by CEN
7、on 15 February 2017. CEN 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
8、 may be obtained on application 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 notifi
9、ed to the CEN-CENELEC Management 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, Icel
10、and, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENEL
11、EC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15774:2017 EBS EN ISO 15774:2017EN ISO 15774:2017 (E) 3 European foreword This document (EN ISO 15774:2017) has been p
12、repared by Technical Committee ISO/TC 34 “Food products” in collaboration with Technical Committee CEN/TC 307 “Oilseeds, 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 s
13、tatus of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2017, 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 su
14、bject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 15774:2001. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implemen
15、t this European Standard: 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, Se
16、rbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 15774:2017 has been approved by CEN as EN ISO 15774:2017 without any modification. BS EN ISO 15774:2017ISO 15774:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and de
17、finitions . 14 Principle 15 Reagents 16 Apparatus . 27 Procedure. 37.1 General . 37.2 Treatment of samples, vegetable oil and standards . 37.3 Preparation of apparatus . 37.4 Determination . 47.4.1 Graphite tube blank . 47.4.2 Vegetable oil . 47.4.3 Calibration of apparatus 47.4.4 Oil (liquid) sampl
18、es . 47.4.5 Fat samples with melting point 40 C and higher . 47.4.6 Number of determinations 58 Expression of results 59 Precision . 59.1 Interlaboratory test. 59.2 Repeatability . 59.3 Reproducibility . 510 Test report . 5Annex A (informative) Results of interlaboratory test 6 ISO 2017 All rights r
19、eserved iiiContents PageBS EN ISO 15774:2017ISO 15774:2017(E)ForewordISO (the International Organization for 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 commit
20、tees. 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, also take part in the work. ISO collaborates closely with the In
21、ternational 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 1. In particular the different approval criteria needed for the d
22、ifferent 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 elements of this document may be the subject of patent rights. IS
23、O 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 received (see www .iso .org/ patents).Any trade name used in this do
24、cument 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 adherence to the World Trade Organization (WTO) principles in th
25、e 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 second edition cancels and replaces the first edition (ISO 15774:2000)
26、, which has been technically revised to exclude its applicability for fat coming from milk and milk products.iv ISO 2017 All rights reservedBS EN ISO 15774:2017INTERNATIONAL STANDARD ISO 15774:2017(E)Animal and vegetable fats and oils Determination of cadmium content by direct graphite furnace atomi
27、c absorption spectrometry1 ScopeThis document describes a method for the determination of trace amounts (micrograms per kilogram) of cadmium in all types of crude or refined edible oils and fats.Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this do
28、cument.2 Normative 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 (inc
29、luding any amendments) applies.ISO 3696, Water for analytical laboratory use Specification and test methods3 Terms and definitionsNo terms and definitions are listed in this document.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia
30、: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp4 PrincipleThe oil or fat is incinerated and atomized in a suitable graphite tube furnace with a platform connected to an atomic absorption spectrometer, previously calibrated us
31、ing standard solutions of an organo-compound of cadmium. The metal content is determined from the observed absorption at a wavelength of 228,8 nm. Palladium is added as a matrix modifier in order to prevent loss of cadmium during the thermal pretreatment.5 ReagentsUse only reagents of recognized ana
32、lytical grade, unless otherwise specified.5.1 Water, of grade 1 according to ISO 3696.5.2 Cyclohexane.5.3 Hydrochloric acid.5.4 Palladium chloride. ISO 2017 All rights reserved 1BS EN ISO 15774:2017ISO 15774:2017(E)5.5 Matrix modifier, 0,1 % (mass/volume) palladium solution.Dissolve 0,167 g of palla
33、dium chloride (5.4) in 50 ml water (5.1) in a 100 ml volumetric flask (6.4), adding 1 ml hydrochloric acid (5.3) and making up to volume with water.5.6 Vegetable oil, refined.Any liquid edible oil is suitable. It shall be stored in a metal-free polyethylene bottle. The cadmium content of the oil sha
34、ll not be greater than 0,2 g/kg.5.7 Organometallic cadmium standard, e.g. Conostan, 5 000 mg/kg1).5.8 Standard stock solution, of concentration 10 mg/kg cadmium, prepared by diluting 200 mg of the organometallic standard (5.7) with 100 g of vegetable oil (5.6).5.9 Standard working solutionsPrepare d
35、aily working solutions containing 2,5 g/kg, 5,0 g/kg and 10,0 g/kg of cadmium by diluting 25 mg, 50 mg and 100 mg, respectively, of the stock solution (5.8) with 100 g of vegetable oil (5.6).5.10 Argon, of 99,99 % minimum purity.6 Apparatus6.1 Polyethylene or polypropylene bottles, of capacities 20
36、ml and 50 ml, metal free, with caps.The bottles are made metal free in the following way. Clean the bottles thoroughly with warm nitric acid (2 mol/l). Rinse with distilled water and dry the bottles in a dust-free drying oven at about 80 C.6.2 Micropipettor, to deliver 10 l and 20 l.6.3 Pipettor tip
37、s.6.4 Volumetric flask, of capacity 100 ml.6.5 Electric oven, capable of being maintained at 60 C 2 C.6.6 Atomic absorption spectrometer, equipped with “peak area” mode and “autocalibrate” mode, together with an appropriate electrode-less discharge lamp (or hollow cathode lamp) and deuterium backgro
38、und corrector (or Zeeman atomic absorption spectrometer).6.7 Graphite furnace atomizer, placed in the atomic absorption spectrometer (6.6), equipped with a control unit for temperature programming.6.8 Graphite tube, uncoated.6.9 Platform, pyrolytic.1) Conostan, available from Continental Oil Company
39、, Ponca City, Oklahoma, USA, is an example of a suitable product available commercially. This information is given for the convenience of users of this document and does not constitute an endorsement by ISO of this product. Equivalent products may be used if it can be shown that they lead to the sam
40、e results.2 ISO 2017 All rights reservedBS EN ISO 15774:2017ISO 15774:2017(E)6.10 Autosampler for graphite furnace atomizer (optional), with polyethylene sample cups.To use an autosampler equipped with a heating device, regulated at 60 C 10 C, fill sample cups with vegetable oil (5.6), standard work
41、ing solutions (5.9) and oil samples. Fat samples with a melting point of 40 C and higher shall be diluted 1:1 (by mass) with blank oil (5.6). The volume of sample injected shall be 15 l.To use an autosampler with no heating device, dilute 1:1 (mass/volume) the vegetable oil (5.6), the standard worki
42、ng solutions (5.9) and oil or fat samples with an organic solvent e.g. cyclohexane (5.2) at ambient temperature. The volume of sample injected shall be 20 l.The use of an organic solvent e.g. cyclohexane (5.2) as a rinse for the autosampler is required.7 Procedure7.1 GeneralEnvironmental dust may co
43、ntribute to background contamination. It is recommended that the analyses be carried out in a dust-free environment.7.2 Treatment of samples, vegetable oil and standards7.2.1 Place all samples, standard working solutions (5.9) and vegetable oil (5.6) in the oven (6.5) set at 60 C.If an autosampler i
44、s used, dilute 1:1 (mass/volume) all solutions (vegetable oil, standard working solutions, samples) with an appropriate solvent e.g. cyclohexane (5.2). Homogenize well before pouring the solution into the sample cups of the autosampler.7.2.2 Shake the samples vigorously if the metal content of a sam
45、ple is known to be outside the given range (5.9). Dilute (by mass) with vegetable oil (5.6).7.3 Preparation of apparatus7.3.1 Switch on the atomic absorption spectrometer and the background correction (deuterium or Zeeman).7.3.2 In accordance with the manufacturers instructions supplied with the spe
46、ctrometer, adjust the lamp current, slit, wavelength and amplification. The required wavelength is 228,8 nm.7.3.3 Optimize the position of the graphite furnace atomizer (6.7) in the atomic absorption spectrometer (6.6) and set the required programme on the control unit of the furnace. Place the plat
47、form (6.9) in the graphite tube (6.8). ISO 2017 All rights reserved 3BS EN ISO 15774:2017ISO 15774:2017(E)7.3.4 Pretreat before each injection the pipettor tip (6.3) by pipetting and then discarding 10 l of cyclohexane (5.2).Table 1 Example of a programme for graphite furnace atomizerStep Temperatur
48、eCRamp timesHold timesInternal gas flowml/minInjection of matrix modifier1 200 30 30 300Injection of oil sample0a60 0 20 01 200 30 30 3002 650 60 40 3003 1 600 0 5 04 2 700 1 3 50aExtra temperature programming step only for fat samples with melting points over 40 C.7.4 Determination7.4.1 Graphite tu
49、be blankRecord the absorption, if any, of the graphite tube (6.8) and autozero this absorption.7.4.2 Vegetable oilBy means of a micropipettor (6.2) or an autosampler (6.10), inject 20 l of the matrix modifier (5.5) into the graphite furnace (6.7) and initiate the modifier temperature programme (step 1; see Table 1). Inject 10 l of the vegetable solution (5.6) into the graphite furnace, initiate the temperature programme (steps 1 to 4) and record the absorption (for the autosampler, see 6.10).7.4.3 Calibration
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