BS EN 13654-1-2001 Soil improvers and growing media - Determination of nitrogen - Modified Kjeldahl method《土壤改良剂和生长剂 氮的测定 改良的基尔达斯法》.pdf

1、BRITISH STANDARD BS EN 13654-1:2001 Soil improvers and growing media Determination of nitrogen Part 1: Modified Kjeldahl method The European Standard EN 13654-1:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 13654-1:20

2、01 This British Standard, having been prepared under the direction of the Consumer Products and Service Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 09 November 2001 BSI 09 November 2001 ISBN 0 580 38268 0 National foreword

3、 This British Standard is the official English language version of EN 13654-1:2001. The UK participation in its preparation was entrusted to Technical Committee AW/20, Top soil and other growing media, which has the responsibility to: A list of organizations represented on this committee can be obta

4、ined 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 Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” f

5、acility 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 their correct application. Compliance with a British Standard does not of itself confer immunity from legal obl

6、igations. 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; monitor related international and European developments and promulgate them in the UK. Summary of pages This

7、 document comprises a front cover, an inside front cover, the EN title page, pages 2 to 10, an inside back cover 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 CommentsEUROPEANSTANDARD

8、 NORMEEUROPENNE EUROPISCHENORM EN136541 September2001 ICS65.080 Englishversion SoilimproversandgrowingmediaDeterminationofnitrogen Part1:ModifiedKjeldahlmethod Amendementsdusoletsupportsdeculture DterminationdelazotePartie1:MthodedeKjeldahl modifie BodenverbessungsmittelundKultursubstrateBestimmung

9、vonStickstoffTeil1:ModifiziertesVerfahrennachKjeldahl ThisEuropeanStandardwasapprovedbyCENon11August2001. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliogr

10、aphicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtoth

11、eManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDI

12、ZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2001CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN136541:2001EEN136541:2001(E) 2 Contents page Foreword .3 1 Scope4 2 Normativereferences

13、 4 3 Termsanddefinitions . 4 4 Principle .4 5 Reagents 4 6 Apparatus.5 7 Testsample. .5 8 Procedure.5 9 Calculation .7 10 Expressionofresults 7 11 Precision 7 12 TestReport .7 AnnexA (informative) Resultsofaninterlaboratorytrialtodeterminenitrogen(modified Kjeldahlmethod) . 8 AnnexB (informative) Me

14、thodsofanalysisusedintheinterlaboratorytrial.9 Bibliography10EN136541:2001(E) 3 Foreword ThisEuropeanStandardhasbeenpreparedbyTechnicalCommitteeCEN/TC223“Soilimproversand growingmedia“,thesecretariatofwhichisheldbyBSI. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationo

15、fanidentical textorbyendorsement,atthelatestbyMarch2002,andconflictingnationalstandardsshallbewithdrawnat thelatestbyMarch2002. TheannexesAandBareinformative. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard

16、:Austria,Belgium,CzechRepublic,Denmark, Finland,France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal, Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN136541:2001(E) 4 SAFETYPRECAUTIONSCareshouldbetakenwhenhandlingsamplesthatmaycontain sharpsorisofadustynature. 1Scope This

17、EuropeanStandardspecifiesamethodforthedeterminationofnitrogeninsoilimproversand growingmedia.TheKjeldahlmethoddeterminesammoniumN,nitrateN,nitriteNandorganicN contentofsoilimproversandgrowingmedia.NitrogeninNNlinkages,NOlinkagesandsome heterocyclics(especiallypyridine)isonlypartiallydetermined.6,7,8

18、 Themethodisnotapplicabletolimingmaterialsandpreformedmaterialssuchasmineralwoolslabs andfoamslabs. NOTE Therequirementsofthestandardmaydifferfromthenationallegalrequirementsforthedeclarationof theproductsconcerned. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,prov

19、isionsfromother publications.Thesenormativereferencesarecitedattheappropriateplacesinthetext,andthe publicationsarelistedhereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofany ofthesepublicationsapplytothisEuropeanStandardonlywhenincorporatedinitbyamendmentor revision.Forundatedreferenc

20、esthelatesteditionofthepublicationreferredtoapplies(including amendments). ENISO3696, WaterforanalyticallaboratoryuseSpecificationandtestmethods(ISO3696:1987). EN13040:1999,SoilimproversandgrowingmediaSamplepreparationforchemicalandphysical test,determinationofdrymattercontent,moisturecontentandlabo

21、ratorycompactedbulkdensity. 3 Termsanddefinitions ForthepurposesofthisstandardthetermsanddefinitionsgiveninEN13040apply. 4Principle Thenitrogencontentofthesampleisdeterminedusingamethodbasedonasulfuricacid/potassium sulfatedigestion.Coppersulfateisusedasthecatalyst. 5Reagents 5.1General Allreagentss

22、hallbeofrecognizedanalyticalgrade.Usewaterofgrade2complyingwithENISO 3696. 5.2 Salicylicacid/sulfuricacid,dissolve25gofsalicylicacid(HO.C 6 H 4 COOH)in1000mlof concentratedsulfuricacid( =1,84g/ml). 5.3 Potassiumsulfatecatalystmixture, grindandthoroughlymix200gofpotassiumsulfate,6gof copper(II)sulfat

23、epentahydrate.(Thismixturemaybeavailablecommercially).EN136541:2001(E) 5 5.4 Sodiumthiosulfatepentahydrate, crushthecrystalstoformapowderthatpassesthrougha sievewithanapertureof0,25mm. 5.5 Calibrationsubstances,puresubstancesofknownnitrogencontent,forexampleacetanilide (C 8 H 9 NO),Lasparticacid(C 4

24、 H 7 NO 4 ),oraminoacidsofknowncomposition. NOTE Thetotalcontentofnitrogenofthecalibrationsubstanceshouldbeassimilartothesamplenitrogen contentaspossible. 6Apparatus Usuallaboratoryapparatus,andinparticularthefollowing: 6.1 Analyticalbalance, capableofweighingaccuratelyto1,0mg. 6.2 Kjeldahldigestion

25、flasks ortubes,ofnominalvalue50ml,suitableforthedigestionsystem (6.3) NOTE Largerflasks(300mlto500ml)mayberequiredforbulkymaterialsorwherealargersamplemass isused. 6.3 Digestionormineralisationsystem withvariableheatingcontrols. 6.4 Sieve, aperture5mm 6.5Stand,capableofholdingthedigestionflasksortub

26、es. 7 Testsample PreparethetestsampleinaccordancewithEN13040:1999,clause9. LossesofnitrogencanoccurwithsamplesofhighammoniumNcontentinalkalinesituationsand particularlywhenthesesamplesaredried.Ifthesamplecontains(orissuspectedtocontain)500 mg/lNH 4 Nfreshbasis,asdeterminedbyprEN13651:20014orprEN1365

27、2:20015,analyzethe freshmaterialassoonaspossible. 8 Procedure 8.1 WARNINGDigestionswithsulfuricacidarepotentiallyhazardousandlaboratorycoats, glovesandsafetyspectaclesorgogglesshallbeused. Thedigestionshallbecarriedoutinawellventilatedfumecupboardwiththerefluxdigestion onatemperaturecontrolledheatin

28、gapparatus.Antibumpinggranules(orroughenedglass beads)maybeaddedbothtotheblankandthesamplestopreventbumpingandlossof solution.Itisimportanttomaintaingentlereflux,bothoftheblankandthetestsamples,to avoidtemperaturefluctuations,whichcouldcauselocalsuperheating. Thetoxicityorcarcinogenicityofeachreagen

29、tusedinthismethodhasnotbeenprecisely defined;however,eachchemicalcompoundneedstobetreatedasapotentialhealthhazard. Fromthisviewpoint,reduceexposuretothesechemicalstothelowestpossiblelevelby whatevermeansavailable. Toxicfumesareevolvedbyboilingsulfuricacid.Alwaysusetheconcentratedacidinafume cupboard

30、.EN136541:2001(E) 6 8.2 Driedsample Placeaportionofthedriedgroundsample( clause7 )ofbetween0,2g(expectednitrogencontent 0,5%)and1,0g(expectednitrogencontent 0,1%)inthedigestionflask(6.2).Add4mlof salicylic/sulfuricacid(5.2)andswirluntiltheacidisthoroughlymixedwiththesample.Allowthe mixturetostandfor

31、severalhours(overnight).Add0,5gofsodiumthiosulfate( 5.4)throughadry funnelwithalongstemthatreachesdownintothebulb,orjustabovetheacidifatubeisused.Heat themixturecautiouslyonthedigestionstand( 6.3)untilfrothinghasceased. Cooltheflask;add1,1gofthecrystallinemixture( 5.3)andheatuntilthedigestionmixture

32、becomes clear.Boilthemixturegentlyforupto5hsothatthesulfuricacidcondensesabout1/3ofthewayup theneckoftheflask.Ensurethatthetemperatureofthesolutiondoesnotexceed400 C. NOTE Inmanycasesaboilingtimeofabout2hissufficient. 8.3 Residualmoisture Themoistureintheanalyzedsample( 8.2)isdeterminedinaccordancew

33、ithEN13040:1999,clause 10,using10gofthedriedsampleobtainedfromEN13040:1999,clause9. 8.4 Freshsamples Freshsamplesshallbereducedinsizetopassa5mmsieveormilledinthepresenceofdryice (solidcarbondioxide).Weighupto20gsampleintoalargeKjeldahlflask.Addsufficient salicylic/sulfuricacid(5.2)untiltheacidisthor

34、oughlymixedwiththesample.Allowthemixtureto standforseveralhours(overnight).Addsodiumthiosulfate( 5.4)(0,5gforevery4mlofacidused) throughadryfunnelwithalongstemthatreachesdownintothebulb.Heatthemixturecautiouslyon thedigestionstand( 6.3)untilfrothinghasceased. Cooltheflask,addthecrystallinemixture( 5

35、.3)(1,1gforevery4mlofacidused)andheatuntilthe digestionmixturebecomesclear.Boilthemixturegentlyforupto5hsothatthesulfuricacid condensesabout1/3ofthewayuptheneckoftheflask.Ensurethatthetemperatureofthesolution doesnotexceed400 C. 8.5 Determinationofammoniumnitrogeninthedigestion Thenitrogeninthediges

36、t,asammonium,maybedeterminedbydistillation,spectrophotometricallyor anyothersuitabletechnique(SeeannexB). 8.6 Moisturecontent DeterminethemoisturecontentofthefreshsampleinaccordancewithEN13040:1999,clause10. 8.7 Blankdetermination Thereagentblanktestshallbecarriedoutinparallelwiththedetermination,by

37、thesameprocedure, outlinedin( 8.2)and (8.4)aboveusingthesamequantitiesofallthereagentsasinthedetermination butomittingthetestportion. NOTE Themeasurementofablankisintroducedtodeterminethecontributionoftheextractingsolutionand glasswareused. 8.8 Calibration Weighoutaquantityofthecalibrationstandard(

38、5.5)equivalentinnitrogencontenttothesamples beinganalyzedandproceedasin( 8.2).Thenitrogendeterminedshouldexceed95%ofthe calculatedvalue.EN136541:2001(E) 7 8.9 Laboratorycompactedbulkdensity DeterminethelaboratorycompactedbulkdensityinaccordancewithEN13040:1999,annexA. 9 Calculation Thenitrogenconten

39、tinmilligramspergramdrymatterormilligramsperlitreasreceivedbasisis calculatedaccordingtothefinalmethodofdeterminationused. 10 Expressionofresults Subtractthevaluesdeterminedforreagentblankfromthoseobtainedforthesamples.Reportall resultsonamass/massbasiscalculatedtoadrymatterbasisormass/volumeonasrec

40、eivedbasis. 11 Precision Therepeatabilityandreproducibilityofthenitrogencontentinseparatelypreparedsamplesshouldbe inaccordancewithTableA.1. Asummaryoftheresultsofaninterlaboratorytrialtodeterminetheprecisionofthemethod,in accordancewithISO57251,isgiveninannexA. NOTE Thevaluesderivedfromthisinterlab

41、oratorytrialmaynotbeapplicabletoconcentrationsand matricesotherthanthosetested. 12 TestReport Thetestreportcanbepreparedseparatelyorinconjunctionwiththetestreportofthesubsequent analyticalmethod. Thetestreportshallincludethefollowinginformation: a)areferencetotheEuropeanStandard; b)acompleteidentifi

42、cationofthesample; c)alltheanalyticalmethodsused; d)astatementwhethergroundorungroundsamplehasbeenused; e)theresultsofthedeterminationexpressedasmass/massondrymatterbasisfordriedsamples;for freshsamplesonamass/massormass/volumebasisasreceivedorcalculatedtomass/massdry matterbasis; f)moisturecontent;

43、 g)thelaboratorycompactedbulkdensity; h)anydetailsnotspecifiedintheEuropeanStandard,orwhichareoptional,aswellasanyother factor,whichmayhaveaffectedtheresults.EN136541:2001(E) 8 AnnexA (informative) Resultsofaninterlaboratorytrialtodeterminenitrogen(modifiedKjeldahlmethod) Aninterlaboratorytrialwasorganisedin1997undertheauspicesoftheEuropeanCommitteeforStandardization,totestthepr oceduresspecifiedinthisEuropeanStandard. InthistrialthenumberoflaboratoriesgiveninTableA.1determinedthenitrogencontentusingthemodifiedKjeldahlmethod insixsample