1、BRITISH STANDARD BS EN ISO 15788-1:2001 BS 684-2.49:2000 Incorporating Amendment No.1 to BS 684-2.49:2000 (renumbers the BS as BS EN ISO 15788-1:2001) Animal and vegetable fats and oils Determination of stigmastadienes in vegetable oils Part 1: Method using capillary-column gas chromatography (Refer
2、ence method) The European Standard EN ISO 15788-1:2001 has the status of a British Standard ICS 67.200.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN ISO 15788-1:2001 This British Standard, having been prepared under the direction of the Consumer Products and Services
3、 Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 15 April 2000 BSI 13 September 2001 ISBN 0 580 34640 4 National foreword This British Standard is the official English language version of EN ISO 15788-1:2001. It is identical w
4、ith ISO 15788-1:1999. The UK participation in its preparation was entrusted to Technical Committee AW/11, Animal and vegetable fats and oils, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The Briti
5、sh Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British
6、 Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to t
7、he responsible 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 f
8、ront cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii and iii, a blank page, pages 1 to 9 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 13
9、237 13 September 2001 Implementation of the European StandardEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO157881 June2001 ICS67.200.10 Englishversion AnimalandvegetablefatsandoilsDeterminationof stigmastadienesinvegetableoilsPart1:Methodusing capillarycolumngaschromatography(Referencemethod)(
10、ISO 157881:1999) CorpsgrasdoriginesanimaleetvgtaleDosagedes stigmastadinesdansleshuilesvgtalesPartie1: Mthodeparchromatographieenphasegazeusesur colonnecapillaire(Mthodederfrence)(ISO15788 1:1999) TierischeundpflanzlicheFetteundleBestimmungder StigmastadieneinPflanzenlenTeil1:Verfahrenmit Kapillarsu
11、lenGaschromatographie(Referenzverfahren) (ISO157881:1999) ThisEuropeanStandardwasapprovedbyCENon13May2001. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliog
12、raphicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtot
13、heManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARD
14、IZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2001CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO157881:2001EForeword ThetextoftheInternationalStandardfromTechnicalCommitteeISO/TC3
15、4“Agriculturalfood products“oftheInternationalOrganizationforStandardization(ISO)hasbeentakenoveras anEuropeanStandardbyTechnicalCommitteeCEN/TC307“Oilseeds,vegetableand animalfatsandoilsandtheirbyproductsMethodsofsamplingandanalysis“,thesecretariat ofwhichisheldbyAFNOR. ThisEuropeanStandardshallbeg
16、iventhestatusofanationalstandard,eitherbypublication ofanidenticaltextorbyendorsement,atthelatestbyDecember2001,andconflicting nationalstandardsshallbewithdrawnatthelatestbyDecember2001. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowingcountriesareboundtoi
17、mplementthisEuropeanStandard:Austria,Belgium, CzechRepublic,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Italy, Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandtheUnited Kingdom. ENISO157881:2001A Referencenumbe r ISO157881:1999 (E) INTERNATIONAL STANDARD ISO 157881 Firste
18、dition 19991015 Animalandvegetablefatsandoils Determinationofstigmastadienesin vegetableoils Part1: Methodusingcapillarycolumngas chromatography(Referencemethod) CorpsgrasdoriginesanimaleetvgtaleDosagedesstigmastadines dansleshuilesvgtales Partie1:Mthodeparchromatographieenphasegazeusesurcolonne cap
19、illaire(Mthodederfrence) ENISO157881:2001)E(9991:188751OSI OSI ii Foreword ISO (the InternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyi
20、nterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectro
21、technicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtoth ememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiesca
22、stingavote. InternationalStandardISO 157881waspreparedbyTechnicalCommitteeISO/TC34, Agriculturalfoodpr oducts, SubcommitteeSC11, Animalandvegetablefatsandoils . ISO15788consistsofthefollowingparts,underthegeneraltitle Animalandvegetablefatsandoils Determinationofstigmastadienesinvegetableoils : Part
23、1:Methodusingcapillarycolumngaschromatography Part2:Methodusinghighperformanceliquidchromatography AnnexAofthispartofISO15788isforinformationonly. ENISO157881:2001OSI )E(9991:188751OSI iii Introduction Significantamountsofhydrocarbonsareformedinvegetableoilsasaconsequenceofthermaltreatmentsduring th
24、erefiningprocesses1.Amongthesehydrocarbons,3,5stigmastadiene,asteroidalcompound,isthemost abundantinallrefinedvegetableoilssinceitisderivedfrom bsitosterolbydehydration2.The3,5stigmastadiene isproducedtogetherwithminoramountsofthe2,4isomerandbothsubstancesgiveasinglewelldefinedgas chromatographicpea
25、kwhenthehydrocarbonfractionisanalysedonalowpolarcolumn3.Therefore,thesumof bothisomerscanbeeasilyquantifiedbygaschomatographicanalysisofthesteroidalhydrocarbonfraction2,4. Forinstance,forvirginoliveoils,theusualoilproductionprocesses(pressureorcentrifuging)donotproduce measurableamountsofstigmastadi
26、enes(lessthan0,01mg/kg).Incrudeoliveresidueoil,smallconcentrationsof stigmastadienesarefound(rangingbetween0,2mg/kgand3mg/kg)duetothehightemperaturesappliedduring thedryingoftherawoliveresidue. Intherefiningprocesses,stigmastadienesareformedinallthestepsinvolvinghightemperatures,suchas bleachingandd
27、eodorizing,butmoreamountsareformedinthefirststepusingacidbleachingearththaninthe second2.Dependingontheconditionsappliedduringtherefiningprocess,commercialrefinedvegetableoils showstigmastadieneconcentrationsrangingbetween1mg/kgand120mg/kgand,therefore,theassessmentof stigmastadienesallowsnotonlythe
28、identificationofthermallytreatedoilsbutalsothedetectionofminoramountsof refinedvegetableoilsinvirginoils. Amethodforthedeterminationofstigmastadienesandtheresultsofacollaborativestudycarriedoutunderthe auspicesoftheInternationalOliveOilCouncilwerepresentedtotheInternationalUnionofPureandApplied Chem
29、istry(IUPAC)CommissiononOils,FatsandDerivatives.Thestigmastadienecontenthasbeenadoptedasan identitycriterionforvirginoliveoilsandtheresultinganalyticalmethodhasbeenadoptedasaninternational standardmethod. ENISO157881:2001ENISO157881:2001DRADNATSLANOITANRETNI OSI )E(9991:188751OSI 1 Animalandvegetabl
30、efatsandoilsDeterminationof stigmastadienesinvegetableoils Part1: Methodusingcapillarycolumngaschromatography(Reference method) 1Scope ThispartofISO 15788specifiesamethodforthedeterminationofstigmastadienesinvirginvegetableoils containinglowconcentrationsofthesehydrocarbons,particularlyinvirginolive
31、oil. Thismethodisapplicabletoallvegetableoilsalthoughmeasurementsarereliableonlywherethecontentofthese hydrocarbonsliesbetween0,01mg/kgand4,0mg/kg.Themethodissuitedtodetectingthepresenceofrefined vegetableoils(olive,olivepomace,sunflower,palm,etc.)invirginoliveoils,sincerefinedoilscontainstigmasta d
32、ienesandcoldextractedoilsdonot. 2Principle Unsaponifiablematterisisolated.Thesteroidalhydrocarbonfractionisseparatedbycolumnchromatographyon silicagelandanalysedbycapillarygaschromatography. 3Reagents Useonlyreagentsofrecognizedanalyticalgrade,unlessotherwisespecified,anddistilledordemineralizedwate
33、ror waterofequivalentpurity. 3.1 Hexane,ormixtureofalkanesofboilingpointfrom65Cto70C,distilledwitharectifyingcolumn. Thehexaneshallberedistilledtoremoveimpurities. 3.2 Ethanol,96%(volumefraction). 3.3 Anhydroussodiumsulfate. 3.4 Alcoholicpotassiumhydroxidesolution, ofconcentration50gper500ml. Add10m
34、lofwaterto50gpotassiumhydroxide,stir,andthendilutethemixturewithethanolto500ml. Alcoholicpotassiumhydroxidesolutionturnsbrownonstanding.Itshouldbepreparedfreshlyeachdayandkeptin wellstoppereddarkglassbottles. ENISO157881:2001)E(9991:188751OSI OSI 2 3.5 Silicagel60 1) ,forcolumnchromatography,70to230
35、mesh. Usually,silicagelcanbeuseddirectlyfromthecontainerwithoutanytreatment.However,somebatchesofsilica mayshowlowactivityresultinginpoorchromatographicseparations.Underthesecircumstances,thesilicagel shouldbetreatedinthefollowingway. Activatethesilicagelbyheatingforatleast4hat550C.Afterheating,plac
36、ethesilicagelinadesiccatorwhilethe geliscoolingandthentransferthesilicageltoastopperedflask.Add2%ofwaterandshakeuntilnolumpscanbe seenandthepowderflowsfreely. Ifbatchesofsilicagelresultinchromatogramswithinterferingpeaks,thesilicagelshouldbetreatedasabove.An alternativewouldbetheuseofextrapuresilica
37、gel60 1) . 3.6 3,5Cholestadiene 2) ,99%purity(massfraction),stocksolutioninhexane,ofconcentration10mgper50ml. 3.7 3,5Cholestadiene ,standardsolutioninhexane,ofconcentrationof1mgper50ml,obtainedbydilutionofthe stocksolution(3.6). NOTE Ifkeptatatemperatureofbelow4C,solutions(3.6)and(3.7)willnotdeterio
38、rateoveraperiodofatleast 4months. 3.8 nNonacosane ,solutioninhexane,ofconcentrationapproximately10mgper100ml. 3.9 3,5Stigmastadiene 3) (24ethylcholesta3,5diene),solutioninhexane,ofconcentrationapproximately10mg per100ml. 3.10 Carriergas ,forchromatography:heliumorhydrogenof99,9990%purity(massfractio
39、n). 3.11 Auxiliarygases ,forflameionizationdetector:hydrogenof99,9990%purity(massfraction),andpurifiedair. 4Apparatus Usuallaboratoryapparatusand,inparticular,thefollowing. 4.1 Flasks,of250mlcapacity,suitableforusewitharefluxcondenser. 4.2 Separatingfunnel ,of500mlcapacity. 4.3 Roundbottomedflasks ,
40、of100mlcapacity. 4.4 Rotaryevaporator. 4.5 Glasschromatographycolumn of1,5cmi.d.and50cmlength,withTeflontapandaplugofglasswoolfibre orsinteredglassdiscatthebottom. Toprepareasilicagelcolumn,pourhexaneintothechromatographycolumntoadepthofapproximately5cmand thenfillwithaslurryofsilicagelinhexane(15gi
41、n40ml)withthehelpofhexaneportions.Allowtosettleandfinish thesettlingbyapplyingslightvibration.Addanhydroussodiumsulfate(3.3)toaheightofapproximately0,5cm. Finallyelutetheexcesshexane. 1) ProductsuppliedbyMerck,ref.7734orsimilarandref.7754(forextrapuresilicagel60). 2) ProductsuppliedbySigma. 3) Produ
42、ctsuppliedbyChironA.S.,Heimdal,Norway. 1) , 2) and 3) ThisinformationisgivenfortheconvenienceofusersofthisInternationalStandardanddoesnotconstitutean endorsementbyISOoftheseproducts.Equivalentproductsmaybeusediftheycanbeshowntoleadthesameresults. ENISO157881:2001OSI )E(9991:188751OSI 3 4.6 Gaschroma
43、tograph ,withaflameionizationdetector,splitoroncolumninjector,andovenprogrammableto within 1C. 4.7 Fusedsilicacapillarycolumns ,forgaschromatography(0,25mmor0,32mmi.d.by25mlength)coated with5%phenylmethylsiliconephase,0,25 m mfilmthickness. NOTE Othercolumnsofsimilarorlowerpolaritycanbeused. 4.8 Integratorrecorder ,withpossibilityofvalleyvalleyintegrationmode. 4.9 Microsyringe,of5 m lto10 m lcapacity,forgaschromatography,withcementedneedle. 4.10 Electricalheatin
