1、BRITISH STANDARD BS EN 14104:2003 Fat and oil derivatives Fatty Acid Methyl Esters (FAME) Determination of acid value The European Standard EN 14104:2003 has the status of a British Standard ICS 67.200.10 BS EN 14104:2003 This British Standard was published under the authority of the Standards Polic
2、y and Strategy Committee on 13 May 2003 BSI 13 May 2003 ISBN 0 580 41836 7 National foreword This British Standard is the official English language version of EN 14104:2003. The UK participation in its preparation was entrusted to Technical Committee AW/307, Animal and vegetables fats and oils, whic
3、h has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the secti
4、on entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Co
5、mpliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor rela
6、ted international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.
7、 Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14104 April2003 ICS67.200.10 Englishversion FatandoilderivativesFattyAcidMethylEsters(FAME) Determinationofacidvalue ProduitsdrivsdescorpsgrasEstersmthyliques dacidesgras(EMAG)Dterminationdeli
8、ndicedacide ErzeugnisseauspflanzlichenundtierischenFettenund lenFettsureMethylester(FAME)Bestimmungder Surezahl ThisEuropeanStandardwasapprovedbyCENon2January2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanat
9、ionalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation underther
10、esponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal
11、,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN1410
12、4:2003EEN14104:2003(E) 2 Foreword Thisdocument(EN14104:2003)hasbeenpreparedbyTechnicalCommitteeCEN/TC307“Oilseeds,vegetable andanimalfatsandoilsandtheirbyproductsMethodsofsamplingandanalysis“,thesecretariatofwhichisheld byAFNOR. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypu
13、blicationofanidenticaltextor byendorsement,atthelatestbyOctober2003andconflictingnationalstandardsshallbewithdrawnatthelatestby October2003. ThisdocumenthasbeenpreparedunderMandateM/245onFattyAcidMethylester(FAME)giventoCENbythe EuropeanCommissionandtheEuropeanFreeTradeAssociation. AnnexAisinformati
14、ve. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal, Slovakia,
15、Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN14104:2003(E) 3 Introduction ThisEuropeanStandardisbasedontheENISO6601whichwasspecificallyadaptedforthedeterminationof acidvalueoffattyacidmethylesters(FAME).EN14104:2003(E) 4 1Scope ThisEuropeanStandardspecifiesonetitrimetricmethodforthedeterminationofa
16、cidvalueinlightcolouredFatty AcidMethylEsters,hereinafterreferredasFAME. Itallowsthedeterminationofacidvaluewithinarangeof0,10mgKOH/gto1,00mgKOH/g. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheap
17、propriateplacesinthetext,andthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendme
18、nts). ENISO661, AnimalandvegetablefatsandoilsPreparationoftestsample(ISO661:1989). ENISO3696, WaterforanalyticallaboratoryuseSpecificationandtestmethods(ISO3696:1987). 3 Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermanddefinitionapply. 3.1 acidvalue numberofmilligramsofpot
19、assiumhydroxiderequiredtoneutralisethefreefattyacidspresentin1gofFAME, whendeterminedinaccordancewiththeprocedurespecifiedinthisEuropeanStandard Acidvalueisexpressedinmilligramsofpotassiumhydroxidepergramofsample. NOTE Ifthesamplecontainsmineralacidstheseare,byconventiondeterminedasapartoftotalacidv
20、alue.Thismethod doesnotallowtodistinguishbetweenweak(fromfreefattyacids)andstrong(frommineralacids,ifpresent)acidity. 4Principle Atestportionisdissolvedinamixedsolventandtitratedwithadilutedsolutionofpotassiumhydroxide,using phenolphthaleinasanindicatorinordertodetectthetitrationendpoint. 5Reagents
21、Useonlyreagentsofrecognisedanalyticalgradeandwaterofgrade3inaccordancewithENISO3696. 5.1 Diethylether and95% ethanol,1+1mixturebyvolume. WARNING Diethyletherisveryflammableandmayformexplosiveperoxides.Usewithgreatcaution. Neutralise,justbeforeuse,byaddingthepotassiumhydroxidesolution(5.2)inthepresen
22、ceof0,3 mlof phenolphthaleinalcoholicsolution(5.3)per100mlofsolventmixture. Ifitisnotpossibletousediethylether,amixedsolventmaybeusedasfollows: tolueneand95%( V/V)ethanol,1+1mixturebyvolume; tolueneand99%( V/V)2propanol,1+1mixturebyvolume.EN14104:2003(E) 5 Themixedsolventcanbereplacedby99%( V/V)2pro
23、panol. NOTE Largervolumesofsolventmixtureandindicatormaybenecessaryfordarkcolouredsamples. 5.2 Potassiumhydroxide ,standardvolumetricsolutioninethanol: mol/l 1 0 (KOH) , = c Theethanolicpotassiumhydroxidesolutioncanbereplacedbyaqueouspotassiumorsodiumhydroxidesolutions, butonlyifthevolumeofwaterintr
24、oduceddoesnotleadtophaseseparation. 5.2.1 Preparationofthesolution Dissolveapproximately7gofpotassiumhydroxidepelletsinethanolanddiluteto1000mlwiththesamesolvent. NOTE 2propanolcanbeusedinsteadofethanol. Weigh,tothenearest0,0002g,0,15gofbenzoicacidhavingminimumpurity99,9%( m/m),oranotherprimary stan
25、dard,ina150mlbeakeranddissolvein50mlof4methylpentan2one(5.4).UseapHmetertofollowtitration andtodetecttheendpoint,startthestirrerandtitratewiththepotassiumhydroxidesolutiontotheequivalence point. 5.2.2 Calculationofthesolutionconcentration Theconcentrationofthepotassiumhydroxidesolution,expressedinmo
26、lesperlitre,(whenbenzoicacidisused),is givenby: 0 0 1 , 122 000 1 V m where m 0 isthemass,reportedingrams,ofbenzoicacidused; V 0 isthevolume,inmillilitres,ofpotassiumhydroxidesolutionusedtoreachtheendpoint. NOTE1 Intheaboveandlatermathematicalexpressions,thesymbolrepresentsthenumericalvaluesofthequa
27、ntities. NOTE2 Potassiumhydroxidestandardisedsolutionsarecommerciallyavailableandsuitableforuse. Usesolutionpreparedatleast5dayspreviouslyanddecantedintoabrownglassbottle,fittedwitharubber stopperprovidedwithathermometerneededfortemperaturecorrection(see10).Thesolutionshallbecolourless orstrawyellow
28、.Ifthebottleisconnectedtotheburette,provisionshallbemadetopreventintakeofcarbon dioxide,forexamplebyusingatubefilledwithgranularsodalime. 5.3 Phenolphthalein,10g/lsolutionin95%Ethanol. 5.4 4Methylpentan2one neutralizedjustbeforeusebyaddingthepotassiumhydroxidesolution(5.2)using thepHmeter(6.3). 6App
29、aratus Usuallaboratoryequipmentand,inparticular: 6.1 Microburette,10mlcapacity,graduatedin0,02mlsubdivisions. 6.2 Analyticalbalance ,capableofweighingwithanaccuracyof 0,05gorless.EN14104:2003(E) 6 6.3 pHmeter ,equippedwithglassandcalomelelectrodes. 7Sampling Samplingisnotpartofthemethodspecifiedinth
30、isEuropeanStandard.Arecommendedsamplingmethodisgiven inENISO55552. Itisimportantthatalaboratoryreceivesasample,whichistrulyrepresentativeandhasnotbeendamagedor changedduringtransportationandstorage. 8 Preparationoftestsample PreparethetestsampleinaccordancewithENISO661.Thetestsampleshallnotbeheateda
31、nd/orfiltered. 9Procedure 9.1 Testportion Takeapproximately20gofthetestsample. Weighthetestportionintoa250mlconicalflask. 9.2Determination 9.2.1 Dissolvethetestportion(9.1)in100mlofpreviouslyneutralisedsolventmixture(5.1). Titrate,whilstswirlingthesolution,withthepotassiumhydroxidesolution(5.2)tothe
32、endpointwhentheadditionof asingledropproducesaslight,butdefinitecolourchangepersistingforatleast15s. 9.2.2 Ifthesolutionbecomesturbidduringtitration,addasufficientquantityofthemixedsolvent(5.1)togivea clearsolution. 10Calculation Theacidvalueisreportedas: m c V 1 , 56 where V isthevolume,inmillilitr
33、es,ofstandardvolumetricpotassiumhydroxidesolutionused; c istheexactconcentration,inmolesperlitre,ofthestandardvolumetricpotassiumhydroxidesolution used; m isthemass,ingrams,ofthetestportion; 56,1isthemolecularmassofpotassiumhydroxide. ResultsareexpressedasmgKOH/gsampleandshallberoundedtotheseconddec
34、imaldigit.EN14104:2003(E) 7 NOTE Theconcentrationoftheethanolicsodiumorpotassiumhydroxidesolutionvarieswithtemperatureanditmaybe usefultousethefollowingcorrection: ) ( 0011 , 0 1 0 t t V V t - - = where V isthecorrectedvolume,inmillilitres,ofthestandardsodiumorpotassiumhydroxidesolution; V t isthevo
35、lume,inmillilitres,ofthestandardsodiumorpotassiumhydroxidesolutionmeasuredattemperature t; t isthetemperatureatwhichthedeterminationwascarriedout,indegreesCelsius; t 0 isthetemperature,indegreesCelsius,atwhichtheconcentrationofthestandardsodiumorpotassiumhydroxide solutionwasdetermined. 11Precision
36、11.1 Interlaboratorytest DetailsofinterlaboratorytestaregiveninannexA.Thevaluesderivedfromthesetestsmaynotbeapplicableto concentrationrangesandmatricesotherthanthosegiven. 11.2Repeatability Theabsolutedifferencebetweentwoindependentsingletestresults,obtainedusingthesamemethodonidentical testmaterial
37、inthesamelaboratorybythesameoperatorusingthesameequipmentwithinashortintervaloftime, shallnotbegreaterthan0,02mgKOH/gmorethanonceoutof20determinations. 11.3Reproducibility Theabsolutedifferencebetweentwosingletestresults,obtainedusingthesamemethodonidenticaltestmaterial indifferentlaboratorieswithdi
38、fferentoperatorsusingdifferentequipment,shallnotbegreaterthan0,06mgKOH/g morethanonceoutof20determinations. 12 Testreport Thetestreportshallspecify: allinformationnecessaryforthecompleteidentificationofthesample; thesamplingmethodusedifknown; thetestmethodused,withreferencetothisEuropeanstandard; al
39、loperatingdetailsnotspecifiedinthisEuropeanStandard,orregardedasoptional,togetherwithdetailsof anyincidentswhichmayhaveinfluencedthetestresult(s); thetestresult(s)obtained,oriftherepeatabilityhasbeenchecked,thefinalquotedresultobtained.EN14104:2003(E) 8 Annex A (informative) Resultsofaninterlaborato
40、rytrial AEuropeancollaborativetestinvolving15laboratoriesin5countrieswascarriedouton5samples: Sample1: FAMEpreparedfromsunfloweroil; Sample2: FAMEpreparedfromrapeseedoil; Sample3: FAMEpreparedfromrapeseedoil; Sample4: FAMEpreparedfromsunflowerandrapeseedoils(75%sunflower); Sample5: FAMEpreparedfromr
41、apeseedoil. ThetestwasorganizedbyCENTC307/WG1in1998andtheresultsobtainedweresubjectedtostatistical analysisinaccordancewithENISO42593togivetheprecisiondatashowninTableA.1. TableA.1 S a m p l e 12345 Nofparticipatinglaboratories 15 15 15 15 15 Nofparticipatinglaboratoriesaftereliminatingoutliers 14 1
42、5 14 15 14 Meanvalue (mgKOH/g) 0,512 0,359 0,882 0,151 0,682 Repeatabilitystandarddeviation(mgKOH/g) 0,004 0,004 0,006 0,003 0,008 Reproducibilitystandarddeviation(mgKOH/g) 0,016 0,022 0,020 0,017 0,017 Repeatabilitylimit, r(mgKOH/g) 0,013 0,011 0,019 0,009 0,024 Reproducibilitylimit R(mgKOH/g) 0,04
43、8 0,067 0,062 0,051 0,052EN14104:2003(E) 9 Bibliography 1 ENISO660, AnimalandvegetablefatsandoilsDeterminationofacidvalueandacidity(ISO660:1996). 2 ENISO5555, AnimalandvegetablefatsandoilsSampling(ISO5555:2001). 3 ENISO4259, PetroleumproductsDeterminationandapplicationofprecisiondatainrelationtomethodsof test(ISO4259:1992/Cor1:1993 ).BS EN 14104:2003 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national bo
