1、BRITISH STANDARD BS EN 1541:2001 Paper and board intended to come into contact with foodstuffs Determination of formaldehyde in an aqueous extract The European Standard EN 1541:2001 has the status of a British Standard ICS 67.250; 85.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYR
2、IGHT LAWBS EN 1541:2001 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 June 2001 BSI 06-2001 ISBN 0 580 37328 2 National foreword This Bri
3、tish Standard is the official English language version of EN 1541:2001. It supersedes BS EN 1541:1998 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee CW/47, Materials in contact with food, to Subcommittee CW/47/3, Paper and board in contact with foods
4、tuffs, which has the responsibility to: A list of organizations represented on this subcommittee 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 Standards C
5、atalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for the
6、ir correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed;
7、monitor related 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 8, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates wh
8、en the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN1541 April2001 ICS67.250;85.060 SupersedesEN1541:1998 Englishversion Paperandboardintendedtocomeintocontactwithfoodstuffs Determinationofformaldehydeinanaqueous
9、extract Papiersetcartonsdestinsentrerencontactavecles denresalimentairesDterminationduformaldhyde dansunextraitaqueux PapierundPappevorgesehenfrdenKontaktmit LebensmittelnBestimmungvonFormaldehydineinem wssrigenExtrakt ThisEuropeanStandardwasapprovedbyCENon19February2001. CENmembersareboundtocomplyw
10、iththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStanda
11、rdexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denm
12、ark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2001CEN Allrightsofexpl
13、oitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN1541:2001EPage2 EN1541:2001 Contents Page Foreword. 3 1 Scope. 4 2 N o r m a t i v e R e f e r e n c e s . 4 3 Termsanddefinitions. 4 4 P r in cip le 4 5 Reagents . 4 6 Apparatus 5 7 Preparationofsample 5 8 Procedure 6 9
14、 Calculationandexpressionofresults. 7 10 Confirmation. 7 11 Repeatabilityandreproducibility. 8 12 Testreport 8Page3 EN1541:2001 Foreword ThisEuropeanStandardhasbeenpreparedbyTechnicalCommitteeCEN/TC172“Pulp,paperandboard“,the secretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusof
15、anationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyOctober2001,andconflictingnationalstandardsshallbewithdrawnatthelatest byOctober2001. ThisEuropeanStandardsupersedesEN1541:1998. WithregardtoEN1541:199806andEN1541:1998/ACthefollowingchangeshavebeenmade: a)deletionof
16、theButan1olstep; b)correctionoftheformula2byincorporationofEN1541:1998/AC; c)additionofmorepreciseinformationonthereproducibility,see11.2; d)editorialupdating. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowing countriesareboundtoimplementthisEuropeanStanda
17、rd:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden, SwitzerlandandtheUnitedKingdom.Page4 EN1541:2001 1Scope ThisEuropeanStandardspecifiesthedeterminationofformaldehydeinaqueousextractspreparedfrompaperand
18、boardintendedtocomeintocontactwithfoodstuffs.Thelimitofdeterminationis1mg/kg.Thismeansthatfora paperwithagrammageof100g/mthelimitofdeterminationwillbe0,001mg/dm. Forcontactatroomtemperaturethecoldwaterextractisapplied.Forpaperandboardmaterialsintendedforboiling andhotfilteringpurposesthehotwaterextr
19、actisapplied. 2Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetextandthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicati
20、onsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). EN645 PaperandboardintendedtocomeintocontactwithfoodstuffsPreparationofacoldwaterextract EN647 Paperandboardintendedtocomeintocont
21、actwithfoodstuffsPreparationofahotwaterextract 3Termsanddefinitions ForthepurposesofthisStandardthefollowingtermsanddefinitionsapply: 3.1coldwaterextract :thewatersolutionobtainedasaresultofcoldextractionEN645. 3.2hotwaterextract: thewatersolutionobtainedasaresultofhotextractionEN647. 4Principle For
22、maldehydereactswithpentane2,4dione(acetylacetone)inthepresenceofammoniumacetatetoform 3,5diacetyl1,4dihydrolutidine.Theabsorbanceoftheextractismeasuredatawavelengthof410nm. NOTETheextractshouldalsobescannedbyultraviolet(UV)spectroscopyforconfirmationwherethelevelof formaldehydeexceedsspecifiedlimits
23、(seeclause10). 5Reagents Allreagentsshallbeofanalyticalgradeandthewatershallbedistilledorofequivalentpurity. 5.1Anhydrousammoniumacetate 5.2Aceticacid99%( d=1,05) 5.3Pentane2,4dione 5.4Hydrochloricacid,1mol/l 5.5Sodiumhydroxidesolution,1mol/l 5.6Starchsolutionfreshlyprepared,2g/l 5.7Formaldehydesolu
24、tion,370g/lto400g/l 5.8Standardiodinesolution,0,05mol/l 5.9Standardsodiumthiosulphatesolution,0,1mol/l 5.10Pentane2,4dionereagent Ina100,0mlvolumetricflaskdissolve: 15,0ganhydrousammoniumacetate(see5.1); 0,2mlpentane2,4dione(see5.3); 0,3mlaceticacid(see5.2); 25mlofwater. Makeupto100,0mlwithwater.Thi
25、sreagentshallbefreshlyprepared. 5.11Reagent(see5.10)withoutpentane2,4dionePage5 EN1541:2001 5.12Formaldehydestandard:Stocksolution Measure5,0mlformaldehydesolution(see5.7)intoa1000mlvolumetricflaskandmakeupto1000mlwithwater. Justbeforeusedeterminetheconcentrationofthissolutionasfollows. Transfer10,0
26、mlofthestocksolutionintoaconicalflask,add25,0mlofastandardiodinesolution(see5.8)and 10,0mlofsodiumhydroxidesolution(see5.5). Allowtostandfor5min. Acidifywith11,0mlofhydrochloricacid(see5.4)anddeterminetheexcessiodinebytitrationwithastandard sodiumthiosulphatesolution(see5.9),using0,1mlofthestarchsol
27、ution(see5.6)asindicator. NOTEAddthestarchsolutionwhenthesolutionbeingtitratedhasbecomeapalestrawcolour.Theoretically,1,0 mlof0,05mol/liodineconsumedisequivalentto1,5mgformaldehyde. 5.13Formaldehydestandard:Dilutesolution Diluteanaliquotoftheformaldehydestocksolution(see5.12)to20timesitsvolumewithwa
28、ter,andthenfurther diluteanaliquotofthissecondsolutionto100timesitsvolumesothat1,0mlofthefinalsolution containsabout 0,001mgofformaldehyde. Usepipettesandvolumetricflasks. Calculatetheactualformaldehydecontent. Thissolutionshallbefreshlyprepared. 6Apparatus 6.1Ordinarylaboratoryapparatus 6.2Spectrom
29、eter foruseatthewavelengthof410nm,withcellsofanopticalpathlengthof10mm. 6.3Scanningultraviolet(UV)spectrometer intherangeof300nmto500nm(Onlyfortheconfirmation steps). 6.4Thermostaticwaterbath capableofmaintainingatemperatureof(602)C. 7Preparationofsample Sampling,samplepreparationandextractionshallb
30、ecarriedoutaccordingtothemethodsforthepreparationof coldwater(seeEN645)orhotwaterextracts(seeEN647). Twoparallelextractionsshallbecarriedout. Thetestshallbeperformednotlongerthan24hafterextraction.Page6 EN1541:2001 8Procedure 8.1 Foreachextractatleasttwoparalleldeterminationsshallbecarriedout. 8.2Sa
31、mplesolution Intoa50mlconicalflaskadd 25,0mlextract( V 1 )(see8.1); 5,0mlpentane2,4dionereagent(see5.10). 8.3Referencesolution Possibleinterferenceduetocolouredsubstancesintheaqueousextractiseliminatedbytheuseofthisreference solution. Intoa50mlconicalflaskadd 25,0mlextract(see8.1); 5,0mlreagentwitho
32、utpentane2,4dione(see5.11). 8.4Blanktest Thisisperformedinordertoconstructthecalibrationcurve. Intoa50mlconicalflaskadd 25,0mlwater; 5,0mlpentane2,4dionereagent(see5.10). 8.5Determination Shakethesolutions8.2,8.3and8.4forabout15s.Immersetheconicalflasksinathermostaticwaterbath(see6.4) at(602)for10mi
33、n10s.Allowtocoolforatleast2mininabathoficedwater. Bringthesolutionsintothemeasuringcells(see6.2).Measuretheabsorbanceat410nmofthesamplesolution (see8.2)withthereferencesolution(see8.3)inthereferencecell( A 1 ). Measuretheabsorbanceoftheblanktest(see8.4)withwaterinthereferencecell( A 2 ). Theabsorban
34、cemeasurementsshallbemadebetween35minand60minfromthetimewhentheconicalflasks wereplacedinthewaterbathat60C. Ifthevalueofformaldehydeobtainedexceedstherangecoveredbythecalibrationsolutions,themeasurementshall berepeatedwithamoredilutesamplesolutionandusinganequallydilutedreferencesolution. 8.6Calibra
35、tioncurve Intoa50mlconicalflaskadd: 1,0mloftheformaldehydedilutedstandardsolution(see5.13); 5,0mlofthepentane2,4dionereagent(see5.10); makeupwithwaterto30,0ml. Continueasdescribedin8.5andmeasuretheabsorbancewithwater(see8.5)inthereferencecell. Repeattheprocedurewith5,0ml;10,0ml;15,0ml;20,0mland25,0m
36、loftheformaldehydedilutedstandard solution(see5.13). Constructthecalibrationcurveaftersubtractionoftheblanktestvalue(see8.5)fromeachof theabsorbances obtained.Page7 EN1541:2001 9Calculationandexpressionofresults 9.1 Subtract A 2 from A 1 andreadofffromthecalibrationcurve(see8.6)theamount Cinmgofform
37、aldehydein thesamplesolution(see8.2). 9.2 Calculatetheformaldehydecontentofthesample( C s )or( C m )asfollows: (1) C s C x V 0 V 1 x b 100 x 1 G (2) C m C x V 0 V 1 x 1 G x 100 100 f x 1000 where: C s amountofformaldehydesolubleofthesampleinmg/dm; C m amountofformaldehydesolubleofthesampleinmg/kg; C
38、 amountofformaldehydereadfromthecalibrationgraph,inmg; V 0 totalvolumeofextract(250ml),inml; V 1 volumetakenforthetest(25,0ml),inml; b grammage,ing/m G mass,ingrams,ofthesampletakenunderthesameconditionasgrammage; f moisturecontentofthesample,in%. Reporttheresultwithtwosignificantfigures. 10Confirma
39、tion 10.1Requirementforconfirmation Wherethelevelofformaldehydeinthewaterextractundertest(seeclause7)exceedsanyspecifiedlimit,the determinationshallbeconfirmedbyscanningultraviolet(UV)spectroscopy(see6.3). 10.2Standardspectrum Whilstpreparingtheformaldehydederivative(see8.5),scantheintermediatestand
40、ard(10,0mlstandardfrom8.6) from300nmto500nm.Recordthepositionandabsorbancevalueatthepeakmaximumandcalculatetheratioof themeasurementsoftheabsorbancemeasuredat20nmincrementseithersideofthemaximum. Thespectrumshallsatisfythefollowingconditions: a)themaximumshallbeintherangefrom408nmto411nm; b)thespect
41、rumshalltendtozeroabsorbance,thatislessthan0,02absorbanceunits,below320nm. ExamplesoftheabsorbanceratiostobeexpectedarelistedinTable1. Maximumabsorbance:410nm Table1Examplesofabsorbanceratiosatcorrespondingwavelengths Wavelengthpair nm Ratio 370/410 0,5200,02 390/410 0,8430,01 430/410 0,8020,01 450/
42、410 0,3860,02Page8 EN1541:2001 10.3Samplespectrum Followingtheprocedureof10.2,recordthespectrumoftherelevantformaldehydesolution,determiningthe absorptionmaximaandtheabsorptionratios.Theseratiosshallagreewiththosefoundforthestandardtowithin 5%.Ifthiscriterionissatisfied,thelevelofformaldehydefoundin
43、equation(1)and/or(2)isconfirmed. 11Repeatabilityandrepr oducibility 11.1Repeatability Fromaninterlaboratorytest( n=9)withbothhotwaterandcoldwaterextractsthetestmethoddescribedabove gaverepeatability( r)asshowninTable2. Table2Repeatabilityfoundinaninterlaboratorytest level coefficientofvariation (r) 0,10mg/dm 10% 0,40mg/dm 5% 11.2Reproducibility Fromaninterlaboratorytest( n=7)thetest
