1、BRITISH STANDARD BS EN 14110:2003 Fat and oil derivatives Fatty Acid Methyl Esters (FAME) Determination of methanol content The European Standard EN 14110:2003 has the status of a British Standard ICS 67.200.10 BS EN 14110:2003 This British Standard was published under the authority of the Standards
2、 Policy and Strategy Committee on 15 May 2003 BSI 15 May 2003 ISBN 0 580 41842 1 National foreword This British Standard is the official English language version of EN 14110:2003. The UK participation in its preparation was entrusted to Technical Committee AW/307, Oilseed animal present to the respo
3、nsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cov
4、er, the EN title page, pages 2 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14110 April2003 ICS
5、67.200.10 Englishversion FatandoilderivativesFattyAcidMethylEsters(FAME) Determinationofmethanolcontent ProduitsdrivsdescorpsgrasEstersmthyliques dacidesgras(EMAG)Dterminationdelateneuren mthanol ErzeugnisseauspflanzlichenundtierischenFettenund lenFettsureMethylester(FAME)Bestimmungdes Methanolgehal
6、tes ThisEuropeanStandardwasapprovedbyCENon2January2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standards
7、maybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official ve
8、rsions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORM
9、ALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN14110:2003EEN14110:2003(E) 2 Foreword Thisdocument(EN14110:2003)hasbeenpreparedbyTechnicalCommitteeCEN/TC307“Oil
10、seeds,vegetable andanimalfatsandoilsandtheirbyproductsMethodsofsamplingandanalysis“,thesecretariatofwhichisheld byAFNOR. This EuropeanStandard shallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyOctober2003,andconflictingnationalstandardsshallbe
11、withdrawnatthelatest byOctober2003. ThisdocumenthasbeenpreparedunderMandateM/245onFattyAcidMethylester(FAME)giventoCENbythe EuropeanCommissionandtheEuropeanFreeTradeAssociation,andsupportsessentialrequirementsofEU Directive(s). AnnexesAandBareinformative. AccordingtotheCEN/CENELECInternalRegulations
12、thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal, Slovakia,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN14
13、110:2003(E) 3 1Scope ThisEuropeanStandardspecifiesamethodforthedeterminationofmethanolcontentinfattyacidmethylesters (FAME)foruseasdieselfuelanddomesticheatingfuel.Themethodisapplicableforaconcentrationrangefrom 0,01%( m/m)to0,5%( m/m)methanol.ThemethodisnotapplicabletomixturesofFAMEwhichcontainothe
14、rlow boilingcomponents. 2Principle Thesampleisheatedat80Cinahermeticallysealedvialtoallowdesorptionofcontainedmethanolintothegas phase.Whenequilibriumisreached,adefinedpartofthegasphaseisinjectedintoagaschromatograph,where methanolisdetectedwithaflameionisationdetector.Normallymethanolistheonlypeaki
15、nthechromatogram. Theamountofmethanoliscalculatedbyreferencetoanexternalcalibration.Methanolcanalsobedetermined afteradditionofaninternalstandardtothesamplebeforeheating,followedbycalculationwiththeuseofan internalcalibrationfactor. NOTE Ifonlymanualequipmentisavailablethenonlyinternalstandardcalibr
16、ationshouldbeused. 3Reagents Useonlyreagentsofrecognizedanalyticalgrade,unlessotherwisespecified. 3.1 Methanol,ofknownpuritygreaterthan99,5%. 3.2 2propanol ,ofknownpurity,greaterthan99,5%(forprocedureA,internalcalibration). 3.3 ReferenceFAME ,withamethanolcontentlessthan0,001%( m/m). NOTE ReferenceF
17、AMEcaneitherbeobtainedfromcommercialsourcesorbywashingbythreeorfivetimeswithdistilled waterinaseparatorfunnel.FAMEshouldbethendriedbyheatingat90Cunderstirringandreducedpressure. 3.4 Carriergas ,nitrogen,heliumorhydrogen,ofknowpuritygreaterthan99%. 4Apparatus 4.1 Septumvials ,20mlcapacity. 4.2 Inerts
18、epta (e.g.TFEorViton 1) ) andmetalliccaps . 4.3 Syringe,10l,accurateto0,1l. 4.4 Gassyringe 500l,fittedwithavalve(formanualprocedure). 4.5 Crimpingpliers. 4.6 Pipettes,of1ml,2ml,5mlcapacity. 4.7 Volumetricflask ,capacity10mland25ml. 1) ThisinformationisgivenfortheconvenienceofusersofthisEuropeanStand
19、ardanddoesnotconstituteanendorsement byCENoftheseproducts.Equivalentproductsmaybeusediftheycanbeshowntoleadtothesameresults.EN14110:2003(E) 4 4.8 Gaschromatograph ,equippedwithacapillarycolumn,suitableinjector(automaticheadspacesystemora split/splitlessinjector)andflameionisationdetector,integrator.
20、 4.9 Capillarycolumn,thecolumnshalleluatemethanolasasymmetricalpeak.Stationaryphaseslike methylpolysiloxane(e.g.DB1 2) ,SE30 2) )orpolyethylenglycol(e.g.DBWAX 2) ,CARBOWAX 2) )canbeused successfullyandafilmthicknessofminimum0,5misrecommended. NOTE Theuseofapackedcolumnequippedbyoneoftheabovementione
21、dstationaryphasesorofChromosorb101 2) is alsoallowed. 4.10 Automaticheadspaceequipment Theautomaticheadspaceequipmentusedshallhavearepeatabilityof1%orbetterconcerningexperimental conditionslikeequilibriumtemperature,heatingtimes,andheadspacesamplingvolume.Thiscanbechecked,if necessary,byrepeatedanal
22、ysisofthesamesample. NOTE Automaticheadspaceequipmentisrecommendedbecauseapart,fromitsbetterrepeatability,itallowsfor automatedandfastanalysisusingexternalcalibration.Manualequipmentcanalsobeused,however,extremecareshouldbe exercisedwhengasvolumesaretakenmanuallyfromthevialsandwheninjectingthemintot
23、hegaschromatograph. 4.11 Analyticalbalance witharesolutionof0,0001g. 4.12 Thermostaticallycontrolledbathoroven ,80C. 4.13 Thermostaticallycontrolledoven ,60C. 5Procedure 5.1Analytical conditions TheGCworkingconditionsshallbechosentakingintoaccountthecharacteristicsofthecolumnandthetypeof carriergast
24、oreachthedesiredresolutionwhichisfixedatminimum1,5forthemethanoland2propanolpeaks. NOTE1 Thefollowingparametersaregivenasanexample: columnDB1(length=30m,internaldiameter=0,32mm,filmthickness=3m); splitinjector(flowrate:50ml/min); injectoranddetectortemperature : 150C; ovenandcolumntemperature : 50C;
25、 carriergas(hydrogen)pressure : 40kPa; volume injected : 500 l. NOTE2 Thefollowingheadspacesamplingconditionsaregivenasanexample: equilibrium temperature : 80 C; equilibrium time : 45 min; samplingvolume : 500l. 2) ThisinformationisgivenfortheconvenienceofusersofthisEuropeanStandardanddoesnotconstit
26、uteanendorsement byCENoftheseproducts.Equivalentproductsmaybeusediftheycanbeshowntoleadtothesameresults.EN14110:2003(E) 5 5.2Operation Thegaschromatographshallbesetupandoperatedaccordingtothemanufacturersinstructions. 6 Calibrationsolutions Threecalibrationsolutionswithapproximatelythefollowingmetha
27、nolconcentrationsinFAME(3.3)shallbe preparedasdescribedbelow. NOTE Threecalibrationsolutionshaveprovensufficientindailypractiseforareliablecoverageoftheconcentrationrange giveninthescopeofthismethod.Forotherconcentrationranges,itisalsopossibletouseotherormorecalibrationsolutio ns. 6.1 Calibrationsol
28、utionA (0,5%( m/m)methanolinFAME). Filla25mlvolumetricflaskwith25mlofFAME(3.3)andadd(112 0,1)mg(142l)methanolintotheliquid phaseusingasyringe(4.3),theadditionbeingmadeintotheliquidphase.Theexactmassesshallbedetermined byweightmeasurement.Itisnecessarytoensurethoroughmixingbyvigorousshaking. 6.2 Cali
29、brationsolutionB (0,1%( m/m)methanolinFAME). Transfer5mlofcalibrationsolutionAintoa25mlanalyticalflaskandcarefullyfilltothemarkwithFAME(3.3). 6.3 CalibrationsolutionC (0,01%( m/m)methanolinFAME). Transfer1mlofcalibrationsolutionBintoa10mlanalyticalflaskandfilltothemarkwithFAME(3.3). 7Procedure Twoal
30、ternativeprocedures,thefirstusinginternalcalibrationandthesecondusingexternalcalibrationare describedinclauses7.1and7.2,respectively. 7.1 ProcedureAUsinginternalcalibration Thisprocedureisgenerallypreferredwhenonlyasmallnumberofsamplesisanalyzedandwhenautomatichead spaceequipmentisnotavailable.Forma
31、nualprocedure,seenoteinclause(4.10). 7.1.1 Internalcalibration (50,01)gfromeachcalibrationsolutionistransferredintoaheadspacevial(4.1)and5lof2propanol(3.2)is addedintotheliquidphaseusingasyringe(4.3),theadditionbeingmadeintotheliquidphase.Thevialsarethen immediatelycrimpedandshakenvigorouslytoensure
32、mixing. Every10min,introduceintothermostaticallycontrolledbathoroven(4.12)avialofthecalibrationsolutionwhich shallbekeptthereforexactly45min. Preheatthegassyringe(4.4)to60Cinanoven(4.13).Sample500lofgaseousphase(headspace)abovethe solutiontobeanalysedandcarryoutthechromatographicanalysis. Thecalibra
33、tionfactor Fiscalculatedforeachcalibrationsolutionaccordingtoequation(1),shallbeexpressed roundedtothenearest0,01. () ) ( m i i m S C S C F = (1) where C i isthe2propanolcontentinthecalibrationsolution,expressedin%( m/m);EN14110:2003(E) 6 (If5lof2propanolareintroducedinto5,0gcalibrationsolution,then
34、 C i =0,0785%( m/m). C m isthemethanolcontentinthecalibrationsolution,expressedin%( m/m); S i isthepeakareaof2propanol; S m isthepeakareaofmethanol. Thecalibrationfactorvaluesobtainedforthethreereferencesolutionsshallexhibitacoefficientofvariationbelow 15%.Ifthisvalueisexceeded,theexperimentalsetups
35、hallbeinspectedforerrorsandthecalibrationprocedure shallberepeatedstartingfromclause(6).Themeanofthesecalibrationfactorvalues(intheregionof0,7)isused forthecalculationdescribedinclause7.1.2. 7.1.2 AnalysisandCalculationusinginternalcalibration Thesamplesshallbepreparedandanalysedwithexactlythesameex
36、perimentalconditionsusedinthecalibration runs(7.1.1).Themethanolcontent C m ofasample,expressedin%( m/m),iscalculatedaccordingtoequation(2) androundedtotwodecimalplaces: i i m m S C S F C = (2) where F isthecalibrationfactorobtainedaccordingtoclause7.1.1; S m isthepeakareaofmethanol; C i is2propanol
37、contentaddedtothesample,expressedin%( m/m); (If5lof2propanolareintroducedinto5,0gsample,then C i =0,0785%( m/m). S i isthepeakareaof2propanol. 7.2 ProcedureBUsingexternalcalibration Thisprocedureisusuallypreferredwhenautomaticheadspaceequipmentisusedandalargenumberofsampled isanalysed.Itisnotrecomme
38、ndedtouseexternalcalibrationwhentheanalysisisexecutedmanually,i.e.without automaticheadspaceequipment. 7.2.1 Externalcalibration 2mlfromeachcalibrationsolutionistransferredintoaheadspacevial.Thevialshallbecrimpedimmediately.The vialsarethenplacedintotheheadspacesamplerandtheanalysisisstartedaccordin
39、gtothemanufacturers instructionmanual. Thecalibrationfunctioniscalculatedusinglinearregression,usingthemethanolcontentsasdependentvariable andthepeakareasasindependentvariable.Usingtheresultingslope, d,andyintercept, e,theregressionfunction isthenconvertedusingequation(3): m m S b a C + = (3) where
40、C m isthemethanolcontentin%( m/m); a isthecoefficientobtainedfrom( e/d );EN14110:2003(E) 7 b isthecoefficientobtainedfrom(1/ d); S m istheareaofthemethanolpeak; d istheslopeofregressionline; e isyinterceptofregressionline. NOTE Ifthecorrelationcoefficientislessthan0,95,theprocedureshouldbeinspectedf
41、orerrorsandthecalibration procedureshouldberepeatedstartingwithclause6. 7.2.2 Analysisandcalculationusingexternalcalibration Thesamplesshallbepreparedandanalysedwithexactlythesameexperimentalconditionsusedinthecalibration runs(7.2.1). Themethanolcontent C m ofasample,expressedin%( m/m),iscalculateda
42、ccordingtoequation(3) androundedtothenearest0,01%( m/m). 8Precision TheprecisiondataforprocedureAandprocedureBhavebothbeenobtainedfromaEuropeaninterlaboratorytrial organisedin1999.Inthisroundrobinexercise,nosignificantdifferenceswereobservedbetweenprocedureAand procedureB(withautomaticheadspacesystemorwithmanualprocedure)forthemethanolconcentrationrange of0,01%to0,20%( m/m). 8.1Repeatability Theabsolutedifferencebetweentwoindependentsingletestresults,obtainedusingthesamemethodonidentical testma
