1、BRITISH STANDARDBS EN ISO 15303:2008Animal and vegetable fats and oils Detection and identification of a volatile organic contaminant by GC/MSICS 67.200.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWNational forewordThis British Standard is the UK implementation of EN ISO 1
2、5303:2008. It is identical with ISO 15303:2001. It supersedes BS ISO 15303:2001, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee AW/11, Animal and vegetable fats and oils.A list of organizations represented on this committee can be obtained on request
3、to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN ISO 15303:2008This British Standard was published under
4、the authority of the Standards Policy and Strategy Committee on 19 October 2001 BSI 2009ISBN 978 0 580 63596 0Amendments/corrigenda issued since publication Date Comments 30 September 2009 This corrigendum renumbers BS ISO 15303:2001 as BS EN ISO 15303:2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE
5、NORMEN ISO 15303November 2008ICS 67.200.10English VersionAnimal and vegetable fats and oils - Detection and identificationof a volatile organic contaminant by GC/MS (ISO 15303:2001)Corps gras dorigines animale et vgtale - Dtection etidentification dun contaminant organique volatil parCPG/SM (ISO 153
6、03:2001)Tierische und pflanzliche Fette und le - Nachweis undIdentifizierung einer flchtigen organischen Verunreinigungmittels 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
7、 the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists
8、in three official versions (English, French, German). A version in any other language made by translationunder the responsibility 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
9、of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN
10、COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 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: EForeword The text o
11、f 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 EN ISO 15303:2008 by Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-produ
12、cts - 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 May 2009, and conflicting national standards shall be withdrawn a
13、t 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 responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the natio
14、nal standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, P
15、oland, 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 15303:2008 without any modification. ii BS EN ISO 15303:2008EN ISO 15303:2008iiiContents Page1 Scope 12 Normative refere
16、nce 13 Principle14 Reagents.25 Apparatus .26 Procedure .36.1 Preparation of standard and blank 36.2 Preparation of internal standards 36.3 Preparation of analytical sample36.4 Determination by GC/MS analysis .36.5 Identification.47 Calculation and expression of results.47.1 Calculation47.2 Expressio
17、n of results 58 Precision.58.1 Interlaboratory tests 58.2 Repeatability.58.3 Reproducibility.5Annex A (informative) Results of interlaboratory tests.6Bibliography10BS EN ISO 15303:2008EN ISO 15303:2008blankINTENRATIONAL TSANDADR1Animal and vegetable fats and oils Detection and identificationof a vol
18、atile organic contaminant by GC/MS1 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 crude and refined edible oils that aresuspected
19、 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 components. In these cases, the presence of
20、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 saturated halogenated hydrocarbons;Gbe unsaturated
21、 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 referenceThe following normative document co
22、ntains 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 this International Standard are encouraged toi
23、nvestigate 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 International Standards.ISO 661:1989, Animal
24、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 of the oil is then introduced into a1BS EN IS
25、O 15303:2008EN ISO 15303:20082 thermal 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 theGC/MS for analysis.4 ReagentsUse only reagents o
26、f 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 standards of benzene, ethyl benzene or naphthalene
27、 (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 laboratory apparatus and, in particular, the following.5
28、.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 diameter.5.5 Gas chromatograph/mass spectrometer, operati
29、ng 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-heated to 160 C. The GCtemperature programme is starte
30、d 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 System is an example of a suitable product availabl
31、e commercially. This information isgiven for the convenience of users of this International Standard and does not constitute an endorsement by ISO of the product.BS EN ISO 15303:2008EN ISO 15303:20083c) MS conditions:Gbe scan one scan per second or faster;Gbe source 70 eV, 200 C, 100 A, 4 kV.d) Gas
32、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 blank.6.1.2 Make up the standard (4.1) (i.e. a pure chemical
33、 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 (usually in the range 1 mg/kg to 10 mg/kg).The standard s
34、olution 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 to 10 mg/kg, i.e. the established linear range for quantif
35、icationwith 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 be the one having the closest GLC retentiontime to that of
36、 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, standard and blank. For best results, allow to stand overnight t
37、o 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 mg of sample and place in the tube. If the observed concen
38、tration 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 blank oil (6.1.1) until theconcentration range is 1 mg/kg
39、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.BS EN ISO 15303:2008EN ISO 15303:20084 6.5 IdentificationCompare the GC retention time and mass spectrum of the anal
40、yte 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 and integrating their areas. This method is used to minimize inte
41、rference 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 concentration of analyte ion;Cisis the concentration of internal st
42、andard.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 the standard is:STD STDRFCG3dGd7where CSTDis the concentration of a
43、nalyte ion in the standard.BS EN ISO 15303:2008EN ISO 15303:20085ThereforeSAM SAMSTD STDCFRCFRGd7G3dGd7SAM STDSAMSTDRCCRGd7G3d7.2 Expression of resultsCarry out duplicate determinations. Report the identity of the contaminant and the mean of the two duplicate valuesobtained for its concentration, pr
44、ovided 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 determinations, provided that the maximum difference between the individual resu
45、lts 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 derived fromthese interlaboratory tests may not be applicable to concentratio
46、n 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 operator using the same equipment within a short interval of time,will in not
47、 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 begr
48、eater 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-ethylmethylaniline, N,N-dimethylaniline, hexan-2-ol, benzene, cumene and ethyl acrylate (see bibliographicreferences).BS EN ISO 15303:2008EN ISO
49、 15303:20086 Annex A(informative)Results of interlaboratory testsA.1 GeneralTwo interlaboratory tests were carried out on the determination of organic chemical contaminants in edible oils. Thefirst of these was carried out in 1993 and is reported in Table A.1. The second was carried out in 1994 and isreported in Table A.3.NOTE It was agreed at the meeting of ISO/TC 34/SC 11 held in April 1996 that in view of the specialized equipmentneeded for this work, the results of these international interlaboratory tests would be judged to be acceptable notw
