1、February 2009DEUTSCHE NORM English price group 10No part of this standard 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!$UvU“150835
2、0www.din.deDDIN EN ISO 15303Animal and vegetable fats and oils Detection and identification of a volatile organic contaminant by GC/MS(ISO 15303:2001)English version of DIN EN ISO 15303:2009-02Tierische und pflanzliche Fette und le Nachweis und Identifizierung einer flchtigen organischen Verunreinig
3、ung mittels GC/MS(ISO 15303:2001)Englische Fassung DIN EN ISO 15303:2009-02www.beuth.deDocument comprises 15 pagesDIN EN ISO 15303:2009-02 2 National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommittee SC 11 “Animal and
4、 vegetable fats and oils” (Secretariat: BSI, United Kingdom) ) in collaboration with Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products Methods of sampling and analysis” (Secretariat: AFNOR, France). The responsible German bodies involved in its prepar
5、ation were the Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee) and the Deutsche Gesellschaft fr Fettwissenschaft DGF (German Fat Research Society), Joint Committee NA 057-05-05 AA Analytik von Fetten, len, Fettprodukten, verwandten S
6、toffen und Rohstoffen. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 661 DIN EN ISO 661 ISO 5725-1 DIN ISO 5725-1 National Annex NA (informative) Bibliography DIN EN ISO 661, Animal and vegetable fats and oils Preparation of test samp
7、le DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 15303November 2008ICS 67.200.10English VersionAnimal and vegetable fats and oils - Detection and identificationof a
8、 volatile organic contaminant by GC/MS (ISO 15303:2001)Corps gras dorigines animale et vgtale - Dtection etidentification dun contaminant organique volatil parCPG/SM (ISO 15303:2001)Tierische und pflanzliche Fette und le - Nachweis undIdentifizierung einer flchtigen organischen Verunreinigungmittels
9、 GC/MS (ISO 15303:2001)This European Standard was approved by CEN on 23 October 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists an
10、d bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibil
11、ity of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ir
12、eland, 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: rue de Stassart, 3
13、6 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 15303:2008: EContents Page1234566.16.26.36.46.577.17.288.18.28.3Annex A (informative)DIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)2Foreword.3Scope 4Normative
14、reference 4Principle4Reagents.5Apparatus .5Procedure .6Preparation of standard and blank 6Preparation of analytical sample6Preparation of internal standards 6Determination by GC/MS analysis .6Identification.7Calculation and expression of results.7Calculation7Expression of results 8Precision.8Repeata
15、bility.8Interlaboratory tests 8Reproducibility.8Results of interlaboratory tests.9Bibliography13Foreword The text of ISO 15303:2001 has been prepared by Technical Committee ISO/TC 34 “Agricultural food products” of the International Organization for Standardization (ISO) and has been taken over as E
16、N ISO 15303:2008 by 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 status of a national standard, either by publication of an i
17、dentical text or by endorsement, at the latest by May 2009, and conflicting national standards shall be withdrawn at the latest by May 2009. 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 resp
18、onsible for identifying any or all such patent rights. 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, Fran
19、ce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 15303:2001 has been approved by CEN as a EN ISO 15303
20、:2008 without any modification. DIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)31 ScopeThis International Standard specifies a method for the detection and identification of a volatile organic contaminantin edible oils.It is applicable to the identification of volatile industrial chemicals in both cru
21、de and refined edible oils that aresuspected of being contaminated. It also enables determination of the concentration of the contaminant.This International Standard is not applicable to the determination of the concentration of chemicals that may reactwith the edible oil or with one of its natural
22、components. In these cases, the presence of the contaminant maysometimes be established on a qualitative basis. Also, this International Standard is not applicable to non-volatilechemicals.This method has been shown to be applicable for the identification of the following compound classes:Gbe satura
23、ted halogenated hydrocarbons;Gbe unsaturated halogenated hydrocarbons;Gbe esters; aldehydes; alcohols; amines; ketones; ethers;Gbe cyclic and aromatic compounds;Gbe nitrogen compounds;Gbe acrylates; etc.The method has been evaluated for concentrations in the range of 1 mg/kg to 10 mg/kg.2 Normative
24、referenceThe following normative document contains provisions which, through reference in this text, constitute provisions ofthis International Standard. For dated references, subsequent amendments to, or revisions of, any of thesepublications do not apply. However, parties to agreements based on th
25、is International Standard are encouraged toinvestigate the possibility of applying the most recent edition of the normative document indicated below. Forundated references, the latest edition of the normative document referred to applies. Members of ISO and IECmaintain registers of currently valid I
26、nternational Standards.ISO 661:1989, Animal and vegetable fats and oils Preparation of test sample3PrincipleA deuterated reference compound with a GC retention time close to that of the suspected contaminant is added tothe oil at a concentration close to that of the suspected contaminant. A sample o
27、f the oil is then introduced into aDIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)4thermal cold-trapping inlet of a GC/MS apparatus. Volatile components evaporate from the oil and are held in thecold trap. The trap is then flash-heated to 160 C and the chemicals released from the trap are swept into t
28、heGC/MS for analysis.4 ReagentsUse only reagents of recognized analytical grade, and distilled or demineralized water or water of equivalent purity.4.1 Standard reference compound, corresponding to suspected contaminating compound (99 % pure).4.2 Methanol, Analar grade.4.3 Fully deuterated internal
29、standards of benzene, ethyl benzene or naphthalene (99 % pure).4.4 Helium, chemically pure grade.4.5 Refined, bleached, deodorized (RBD) groundnut oil, or a similar stable vegetable liquid oil, known to befree of industrial chemicals related to the analyte under consideration.5 ApparatusUsual labora
30、tory apparatus and, in particular, the following.5.1 Capillary gas chromatograph.5.2 Mass spectrometer.5.3 Thermal desorption cold-trapping device1).5.4 Capillary column, of length 50 m, methyl polysiloxane with OV101 (or equivalent) stationary phase, 0,5 mfilm thickness and 0,32 mm internal diamete
31、r.5.5 Gas chromatograph/mass spectrometer, operating under the following conditions.a) Thermal desorption cold-trapping temperature programme (at injection):Gbe thermal cold trap oven 160 C;Gbe thermal cold trap below 40 C.The trap is held at a temperature below 40 C for 5 min and is then flash-heat
32、ed to 160 C. The GCtemperature programme is started simultaneously with the flash-heating of the trap. The trap is held at 160 Cfor 3 min.b) GC temperature programme:Gbe initial temperature 50 Cfor5min;Gbe increase at 7,5 C per min;Gbe final temperature 250 Cfor5min.1) The Chrompack Purge and Trap S
33、ystem is an example of a suitable product available commercially. This information isgiven for the convenience of users of this International Standard and does not constitute an endorsement by ISO of the product.DIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)5c) MS conditions:Gbe scan one scan per sec
34、ond or faster;Gbe source 70 eV, 200 C, 100 A, 4 kV.d) Gas flows:Gbe column 1 ml/min helium;Gbe split during cold trapping 5 ml/min.5.6 Vortex mixer.6 Procedure6.1 Preparation of standard and blank6.1.1 Use a refined, bleached and deodorized vegetable oil e.g. groundnut (4.5) as a carrier and as a bl
35、ank.6.1.2 Make up the standard (4.1) (i.e. a pure chemical of known composition, corresponding to that of thesuspected contaminant) in a concentrated form (e.g. 100 mg/kg) in the carrier oil (6.1.1). This is the stock solution.Dilute this stock solution with carrier oil to the required concentration
36、 (usually in the range 1 mg/kg to 10 mg/kg).The standard solution should be of a similar concentration to the contaminant in the sample.6.1.3 Dilute the suspect oil, if necessary, with the carrier oil (4.5) so that the concentration of the suspectedcontaminant is likely to be in the range 1,0 mg/kg
37、to 10 mg/kg, i.e. the established linear range for quantificationwith this method.6.2 Preparation of internal standardsPrepare a solution of deuterated benzene, ethyl benzene or naphthalene (4.3) in methanol (4.2) at a concentrationof 0,1 g/l (0,1 g/l) as needed. The internal standard chosen should
38、be the one having the closest GLC retentiontime to that of the analyte.6.3 Preparation of analytical sampleAccurately weigh 1,00 g of the oil under test. Add 5,0 l of internal standard solution in methanol (4.2), selectedaccording to 6.2. Mix on the vortex mixer (5.6).Repeat with all samples, standa
39、rd and blank. For best results, allow to stand overnight to allow equilibration.6.4 Determination by GC/MS analysisThe following conditions have been found to be satisfactory.Pack an empty thermal cold-trapping (TCT) tube with clean glass wool to a length of about 3 cm to 4 cm. Takeapproximately 10
40、mg of sample and place in the tube. If the observed concentration of the contaminant exceeds10 mg/kg, following analysis of a 10 mg portion of oil, repeat the determination with a sample size of 2,5 mg. Forstill larger concentrations, it is recommended that the sample be accurately diluted with the
41、blank oil (6.1.1) until theconcentration range is 1 mg/kg to 10 mg/kg (see 6.1.3).Pre-cool the cold trap to below 20 C, and continue cooling to below 40 C. Fit the tube containing the oil in theTCT oven and start the TCT and GC/MS programmes.DIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)66.5 Identifi
42、cationCompare the GC retention time and mass spectrum of the analyte with those of the standard. Identification requiresa good match of both spectra and GC retention times.Quantification is performed by using reconstructed ion chromatograms of selected ions from the analyte and theinternal standard
43、and integrating their areas. This method is used to minimize interference from co-elutants.7 Calculation and expression of results7.1 CalculationThe peak area of the analyte ion divided by the peak area of the internal standard ion is the response ratio R:isKCRCGd7G3dwhereK is a constant;C is the co
44、ncentration of analyte ion;Cisis the concentration of internal standard.SAMSAMisRKCCG3dGd7whereRSAMis the value of R for the sample;CSAMis the concentration of analyte ion in the sample.Since Cisis a constant by definition:SAM SAMRFCG3dGd7where the factor F isisKFCG3dSimilarly, the value of R for th
45、e standard is:STD STDRFCG3dGd7where CSTDis the concentration of analyte ion in the standard.DIN EN ISO 15303:2009:02EN ISO 15303:2008 (E)7ThereforeSAM SAMSTD STDCFRCFRGd7G3dGd7SAM STDSAMSTDRCCRGd7G3d7.2 Expression of resultsCarry out duplicate determinations. Report the identity of the contaminant a
46、nd the mean of the two duplicate valuesobtained for its concentration, provided the repeatability limit in 8.2 is satisfied. Otherwise, repeat the determinationon two further test portions. If this time the difference again exceeds 0,6 mg/kg, take as the result the arithmeticmean of the four determi
47、nations, provided that the maximum difference between the individual results does notexceed 1,0 mg per kilogram of oil.Report the result to one decimal place.8 Precision8.1 Interlaboratory testsDetails of interlaboratory tests on the precision of the method are summarized in annex A. The values deri
48、ved fromthese interlaboratory tests may not be applicable to concentration ranges and matrices other than those given.8.2 RepeatabilityThe absolute difference between two independent single test results, obtained using the same method on identicaltest material in the same laboratory by the same oper
49、ator using the same equipment within a short interval of time,will in not more than 5 % of cases be greater than 0,6 mg/kg.8.3 ReproducibilityThe absolute difference between two single test results, obtained using the same method on identical test materialin different laboratories with different operators using different equipment, will in not more than 5 % of cases begreater than 1,43 mg/kg.NOTE This method has been ring tested with 1,1,1-trichloroethane, 2-ethyl hexyl acrylate, dicylopentadiene, tetrachloro-ethylene, N,N-ethylmethylani
