NISTSpecialPublication260-CertificationofStandardReferenceMaterial?1992/ERM?-ZetaPotential–ColloidalSilica(NominalMassFraction0.15November

NIST（0.15）202011ThispublicationThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-ThisreportdescribestheproductionofSRM1992/ERM-FD305,silicaparticlessuspendedinboratebuffer,certifiedforelectrophoreticmobilityandzetapotentialbyelectrophoreticlightscattering(ELS).ThismaterialwasproducedfollowingISO17034:2016andiscertifiedinaccordancewithISOGuide35:2017.Thecertifiedreferencematerial(CRM)wasjointlyproducedbytheDirectorateF-Health,ConsumersandReferenceMaterialsoftheEuropeanCommission’sJointResearchCentre(JRC)inGeel(Belgium)andtheUSNationalInstituteofStandardsandTechnology(NIST),Gaithersburg(USA).TheCRMwasproducedfromabuffer-modifiedanddilutedcommercialcolloidalsilicaslurry.Between-ampoulehomogeneitywasquantifiedandstabilityduringdispatchandstoragewereassessedinaccordancewithISOGuide35:2017.TheminimumsampleintakefortheELSmethodwasdeterminedfromtheresultsandinformationprovidedbythelaboratoriesthatparticipatedintheinterlaboratorycomparison(ILC)exercise.ThematerialwascharacterizedbyaninterlaboratorycomparisonbetweenlaboratoriesofdemonstratedcompetenceandadheringtoISO/IEC17025.Technicallyinvalidresultswereremovedbutnooutlierwaseliminatedsolelyonstatisticalgrounds.UncertaintiesofthecertifiedvalueswerecalculatedinaccordancewiththeGuidetotheExpressionofUncertaintyinMeasurement(GUM)andincludeuncertaintiesrelatedtopossibleinhomogeneity,instabilityandcharacterization.Thematerialisintendedforqualitycontrolandassessmentofmethodperformance.TheCRMisavailablein5mLpre-scoredamberglassampouleseachcontainingapproximately5mLofsuspension.Keyelectrokineticpotential;electrophoreticmobility;lightscattering;silica;surfacecharge;zetapotential.

802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup本報(bào)告描述了SRM1992/ERM?FD305的生產(chǎn)，即懸浮于硼酸鹽緩沖液中的二氧化硅顆粒，該材料經(jīng)電泳光散射（ELS）認(rèn)證了其電泳遷移率和zeta電位。該材料按照ISO17034:2016標(biāo)準(zhǔn)生產(chǎn)，并依據(jù)ISOGuide35:2017進(jìn)行認(rèn)證。該有證參考材料（CRM）由歐洲委員會(huì)聯(lián)合研究中心（JRC）位于比利時(shí)吉爾的健康、消費(fèi)者和參考材料局F與美利堅(jiān)合眾國(guó)國(guó)家標(biāo)準(zhǔn)與技術(shù)研究院（NIST）位于蓋瑟斯堡的機(jī)構(gòu)共同生產(chǎn)。CRM是由緩沖液改性并稀釋的商業(yè)膠體二氧化硅漿料制成的。根據(jù)ISOGuide35:2017標(biāo)準(zhǔn)，對(duì)安瓿瓶間均勻性進(jìn)行了定量評(píng)估，并對(duì)其在運(yùn)輸和儲(chǔ)存期間的穩(wěn)定性進(jìn)行了評(píng)估。根據(jù)參與實(shí)驗(yàn)室間比對(duì)（ILC）活動(dòng)的實(shí)驗(yàn)室提供的結(jié)果和信息，確定了ELS方法的最低樣品取用量。該材料通過(guò)在具有證明能力和遵守ISO/IEC17025標(biāo)準(zhǔn)的實(shí)驗(yàn)室之間進(jìn)行的實(shí)驗(yàn)室間比對(duì)進(jìn)行了表征。已移除技術(shù)無(wú)效的結(jié)果，但未僅基于統(tǒng)計(jì)原因消除任何離群值。根據(jù)測(cè)量不確定度表示指南（GUM）計(jì)算了認(rèn)證值的uncertainties，并包括與可能的非均勻性、不穩(wěn)定性以及表征相關(guān)的unce802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupmL懸浮液的5mLTableof Selectionofthe DesignoftheCRM Projectmanagementand Homogeneity Stability Materialprocessingandprocess Originofthestartingmaterialandavailable Process Between-ampoule Within-unithomogeneityandminimumsample Short-termstability Long-termstability Estimationof Selectionof Study Methods Electrophoreticlightscattering Zetapotentialbyparticletrackinganalysis(Z- Evaluationof Technical Statistical

802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahc802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup 研究設(shè)置 Thispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260- ValueThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-ThispublicationisavailablefreeofchargeThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-Additionalmaterial Zetapotentialbyparticletracking Electricalasymmetrical-flowfield-flow Metrologicaltraceabilityand Metrological Instructionsfor Safety Storage Preparationanduseofthe Minimumsample Useofthecertified

Certifiedvaluesandtheir ζ Electricalasymmetrical-flowfield-flow Metrologicaltraceabilityand 802-062.PS.TSIN/8206.01/gro.iod//:sptth:morf802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup ThispublicationisThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-Sphere Analysisof AvalanchephotodiodeSlopeofregressionlineinstability ConsultativeCommitteefor ComitéInternationaldesPoidsetMesures(InternationalCommitteeofWeightsandMeasures) Certifiedreference Dynamiclight Electricfield Electricaldouble Electrophoreticlight Electron TrademarkoftheEuropeanReferenceMaterials EuropeanUnion GuidetotheExpressionofUncertaintyinMeasurement InternationalElectrotechnicalCommission InternationalOrganizationforStandardization ISO/technicalcommittee24/subcommittee4 JointResearchCentreoftheEuropean Coverage Meanofsquaresbetween-ampoulefroman Meanofsquareswithin-unitfromanANOVA Refractiveindexofthemedium Notapplicable(ornot NationalInstituteofStandardsand Numberoftechnicallyvalid Phaseanalysislight Particlesize

802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup 球體半徑ANOVA方差分析APD雪崩光電二極管探測(cè)器b穩(wěn)定性研究中回歸線的斜率CCL長(zhǎng)度咨詢委員會(huì)CIPM國(guó)際計(jì)量委員會(huì)（國(guó)際度量衡委員會(huì)）CRM認(rèn)證參考材料DLS動(dòng)態(tài)光散射E電場(chǎng)強(qiáng)度EDL電雙層ELS電泳光散射EM電子顯微鏡ERM?歐洲參考材料的商標(biāo)EU歐洲聯(lián)盟GUM測(cè)量不確定度表示指南IEC國(guó)際電工委員會(huì)ILC實(shí)驗(yàn)室間比對(duì)ISO國(guó)際標(biāo)準(zhǔn)化組織ISO/TC24/SC4ISO/技術(shù)委員會(huì)24/分委員會(huì)4JRC歐洲委員會(huì)聯(lián)合研究中心k 覆蓋因子MSbetween來(lái)自ANOVA的批間均方MSwithin來(lái)自ANOVA的批內(nèi)均方n介質(zhì)的折射率n.a.不適用（或不可用）NIST美國(guó)國(guó)家標(biāo)準(zhǔn)與技術(shù)研究院802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup Particletracking Quality Relative Refractive Reference RelativestandardStandard Between-ampoulestandarddeviation;anadditionalindex"rel"isaddedwhenappropriate StandarddeviationbetweengroupsasobtainedfromANOVA Scanningelectronmicroscopy InternationalSystemof TrademarkoftheNationalInstituteofStandardsand Standarddeviationwithingroupsasobtainedfrom Within-unitstandarddeviation;anadditionalindex"rel"isaddedwhenMeanofall Timeelapsedattimepoint Shelf Transport Transmissionelectron Tangentialflow Transmission-modescanningelectron Expandeduncertainty;anadditionalindex"rel"isaddedwhenStandarduncertainty;anadditionalindex"rel"isaddedwhen

ti

Standarduncertaintyrelatedtoamaximumbetween-ampouleinhomogeneitythatcouldbehiddenbymethodrepeatability;anadditionalindex"rel"isaddedwhenappropriate

當(dāng)適用時(shí)，會(huì)添加附加索引"rel"Thispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup Combined Standarduncertaintyofthematerialcharacterization;anadditionalindex"rel"isaddedwhenappropriate Combinedstandarduncertaintyofthecertifiedvalue;anadditionalindex"rel"isaddedwhenappropriate

inhomogeneity;anadditionalindex"rel"isaddedwhenappropriate Combined Standarduncertaintyofthematerialcharacterization;anadditionalindex"rel"isaddedwhenappropriate Combinedstandarduncertaintyofthecertifiedvalue;anadditionalindex"rel"isaddedwhenappropriateThispublicationisavailableThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup Combinedstandarduncertaintyofmeasurementresultandcertified Standarduncertaintycorrespondingwithapotentialdegradationobservedinthestabilitystudy Standarduncertaintyofthelong-termstability;anadditionalindex"rel"isaddedwhenappropriate Uncertaintyestimatedfromarectangular Standarduncertaintyoftheshort-termstability;anadditionalindex"rel"isaddedwhenappropriate Arithmetic Zetapotentialmeasurementby Absolutedifferencebetweenmeanmeasuredvalueandthecertified Dopplerfrequency Dielectricpermittivityofthe Zeta Dynamic Anglebetweentheincidentlightandthescattered Anglebetweenthetwo ReciprocaloftheDebyedouble Laserwavelengthinthe Effectivedegreesof Degreesoffreedomof

PTAζ Zeta MSwithin ThisreportdescribestheproductionofSRM1992/ERM-FD305,silicaparticlessuspendedinaboratebuffer,certifiedforelectrophoreticmobilityandzetapotentialbyelectrophoreticlightscattering(ELS).ThismaterialwasproducedfollowingISO17034:2016[1]andiscertifiedinaccordancewithISOGuide35:2017[2].Thecertifiedreferencematerial(CRM)wasjointlyproducedbytheDirectorateF-Health,ConsumersandReferenceMaterialsoftheEuropeanCommission’sJointResearchCentre(JRC)inGeel(Belgium)andtheUSNationalInstituteofStandardsandTechnology(NIST),Gaithersburg(USA).TheCRMwasproducedfromabuffer-modifiedanddilutedcommercialcolloidalsilicaslurry.Between-ampoulehomogeneitywasquantifiedandstabilityduringdispatchandstoragewereassessedinaccordancewithISOGuide35:2017[2].TheminimumsampleintakefortheELSmethodwasdeterminedfromtheresultsandinformationprovidedbythelaboratoriesthatparticipatedintheinterlaboratorycomparison(ILC)exercise.ThematerialwascharacterizedbyaninterlaboratorycomparisonbetweenlaboratoriesofdemonstratedcompetenceandadheringtoISO/IEC17025[3].Technicallyinvalidresultswereremovedbutnooutlierwaseliminatedsolelyonstatisticalgrounds.UncertaintiesofthecertifiedvalueswerecalculatedinaccordancewiththeGuidetotheExpressionofUncertaintyinMeasurement(GUM)[4]andincludeuncertaintiesrelatedtopossibleinhomogeneity,instabilityandcharacterization.Thematerialisintendedforqualitycontrolandassessmentofmethodperformance.TheCRMisavailablein5mLpre-scoredamberglassampouleseachcontainingapproximately5mLofsuspension.Thefollowingcertifiedvalueswere

SRM1992/ERM?FD305的生產(chǎn)，這是一種懸浮在硼酸鹽緩沖液中的二氧化硅顆粒，通過(guò)電泳光散射（ELS）zetaISO17034:20161]ISOGuide35:2017[2]進(jìn)行認(rèn)證。802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupISOGuide35:2017[2]，對(duì)安瓿瓶間均勻性進(jìn)行了定量，并評(píng)估了在運(yùn)輸和儲(chǔ)存期間的穩(wěn)定性。ELS（ILC）活動(dòng)提供的實(shí)驗(yàn)室結(jié)果和信ISO/IEC17025[3]的具有已證明能力的實(shí)驗(yàn)室之間的實(shí)驗(yàn)室間比對(duì)進(jìn)行了表征。根據(jù)測(cè)量不確定度表示指南（GUM）[4]uncertainties，包括與可能的該材料用于質(zhì)量控制和方法性能評(píng)估。CRM5mL5mL的懸浮液。ThispublicationThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-Meanelectrophoreticmobility(10-8m2V-1?s-Meanzetapotential(mV)3)Certifiedvaluesarevaluesthatfulfilthehigheststandardsofaccuracyandrepresenttheunweightedmeanvalueofthemeansofacceptedsetsofdata;eachsetbeingobtainedinadifferentlaboratoryorwithadifferentmethodofdetermination.ThecertifiedvalueanditsuncertaintyaretraceabletotheInternationalSystemofunits(SI).4)Theuncertaintyistheexpandeduncertaintyofthecertifiedvaluewithacoveragefactork=2correspondingtoalevelofconfidenceofabout95%estimatedinaccordancewithISO17034:2016andISOGuide35:2017.(10-8m2V-1?s- 2)根據(jù)認(rèn)證的遷移率值使用Smoluchowski近似計(jì)算得到f(κa)= 認(rèn)證值是滿足最高精度標(biāo)準(zhǔn)并代表接受數(shù)據(jù)集的未加權(quán)平均值；每個(gè)數(shù)據(jù)集在不同的實(shí)驗(yàn)室或使用不同的方法獲 nvaluemethod4)Theuncertaintyistheexpandeduncertaintyofthecertifiedvaluewithacoveragefactork=2correspondingtoalevelofconfidenceofabout95%estimatedinaccordancewithISO17034:2016andISOGuide35:2017.ThispublicationisavailablefreeofThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-Zetapotentialisaparameterthatcanbeusedtopredictthelong-termstabilityofsuspensionsandemulsionsandtostudysurfacemorphologyandadsorptionontoparticlesandothersurfacesincontactwithaliquid.Zetapotentialisnotadirectlymeasurableparameter.Itcanbedeterminedusingappropriatetheoreticalmodelsfromexperimentallydeterminedparameters,suchaselectrophoreticmobility.Traditionally,zetapotentialisdefinedastheelectricpotential(relativetothebulkmedium)atorneartheshear(slipping)plane,animaginaryshortdistancedisplacedfromtheparticlesurface.Itsvalueisrelatedto,butdiffersfrom,thesurfacepotential.TheelectrophoreticmobilitycanbemeasuredbyacousticmethodsusingtheelectroacousticphenomenadescribedinthedocumentarystandardsISO13099,Part1[5]andPart3[6],andbyopticalmethods,especiallyelectrophoreticlightscattering(ELS),asdescribedinISO13099Part1[5]andPart2[7])TheprojecttodevelopacommonCRMforbothelectroacousticandopticaltechniqueswasbornoutofcontactsbetweenmembersofISO/TC24/SC4fromNISTandJRC,withthecriticalsupportofindustrymembers.TheCRMshallservetwopurposes:Itmaybeusedasqualitycontrolmaterialforelectrophoreticmethods.Electrophoreticmethodsarebasedonfirstprinciplesandthereforedonotrequireacalibrant.Itmayserveascalibrationmaterialforacousticmethods.Unlikeelectrophoreticmethods,electroacousticmethodsrequirecalibration.ThisiscurrentlyaccomplishedusingLudoxTM(commercialcolloidalsilica)andusingavalueforitszetapotentialpublishedinthe1960s,orusingapotassiumsilicotungstate(KSiW)electrolytesolutionwithaknowndynamicmobility.However,thetypicalworkingconcentrationrangesfortheacousticandopticalbasedmethodsaregenerallyatoppositeendsofthespectrum.Indeed,opticalmethods(electrophoretic)requireanopticallydilutesample,whereaselectroacousticmethodsaregenerallyappliedtoconcentratedopticallyopaquesuspensions.Despitesomeoverlap(materialdependent)oftheupperlimitforopticalmethodsandthelowerlimitforacousticmethods,referencematerialsshouldbeproducedatthemostrelevantparticlemassconcentrations:onedilutematerial(1.5gkg-1),SRM1992/ERM-FD305suitableforopticalmethods;theproductionofwhichisdescribedinthisreport.oneconcentratedmaterial(22gkg-1),ERM-FD306/SRM1993,suitableforacousticmethods,theproductionofwhichisdescribedelsewhere[8],Thesamematerialsarereleasedandco-brandedbytheJRCandNISTundertheirownCRMcodes(SRM1992/ERM-FD305andERM-FD306/SRM1993,respectively).ThisreportwillthereforerefertobothcodesforthesameCRM.Thebasisoftheprojectisthatitispossibletodilutesuspensionswithoutchangingthezetapotential,aslongastheoriginalsuspendingmediumisusedfordilution[5].Thisprovidesthepossibilitytocertifythezetapotentialofaconcentratedsuspensionusingelectrophoreticmethods.Forthisstudy,thezetapotentialvalueisassignedindirectlyfromthemeasurementofelectrophoreticmobilitybyapplyingtheHenryequation(Equation1)[5]andusingthethinelectricdoublelayer(EDL)assumption(i.e.,theSmoluchowskiapproximation)

引言802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfo802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup第1[5]部分和第3[6部分，以及通過(guò)光學(xué)方法，特別是電泳光散射（ELS），ISO130991[5]部分和第2[7]CRMISO/TC24/SC4NISTJRC接觸，并得到了行業(yè)成員的關(guān)鍵支持。CRM1960zetaLudoxTM（商業(yè)膠體二氧化硅）或使用具有已知?jiǎng)討B(tài)遷移率的硅鎢酸鉀（KSiW）電解質(zhì)溶液來(lái)完成的。1.5gkg-1SRM1992/ERM?FD305適用于光學(xué)方法；其生產(chǎn)在本報(bào)告中有所22gkg-1ERM?FD306/SRM1993相同的材料由JRC和NIST以各自的CRM代碼（SRM1992/ERM?FD305和ERM?FD306/SRM1993，分別）發(fā)布和聯(lián)合品牌。因此，本報(bào)告將針對(duì)相同的CRM這兩個(gè)代碼。該項(xiàng)目的依據(jù)是，只要使用原始懸浮介質(zhì)進(jìn)行稀釋，稀釋懸浮液而不會(huì)改變zeta電位，[5。這提供了使用電泳方法認(rèn)證濃縮懸浮液zeta電位的可能性。對(duì)于這項(xiàng)研究，zeta（1）[5并使用薄電雙層（EDL）假設(shè)（即，Smoluchowski）從電泳遷移率的測(cè)量中間接分配的。

??=2??????. Eq. electrophoreticmobility(m2?V-1?s-1orA?s2?kg-

??=2?????? 802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupμ............電泳遷移率(m2?V-1?s-1或802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup potential(Vorkg?m2?s-3?A- dynamicviscosityofthemedium(Pa.sorkg?m-1?s- dielectricpermittivityofthemedium(F?m-1ors4?A2?m-3?kg- sphereequivalentradius reciprocalDebyedoublelayerthickness(m- Henry’sfunctionTheratiooftheparticleradiustotheEDLthicknessisgivenbythedimensionlessparameterκa,whichvariesfrom0to.ThemonotonicHenryfunctionf(κa)approachesunityfortheHückelmodel(thickEDL,κa<<1)and1.5fortheSmoluchowskiapproximation(thinEDL,κa>>1).Therefore,intheSmoluchowskilimit,thezetapotentialiscalculatedasfollows(Equation

kg?m2?s-3?A-1)η0...........介質(zhì)的動(dòng)態(tài)粘度(Pa.s或kg?m-1?s-1)ε.............介質(zhì)的介電permittivity(F?m-1或s4?A2?m-3?kg-1)a 半徑(m)κ.............德拜雙電層厚度的倒數(shù)(m-1) 亨利函數(shù)κa0。單調(diào)亨利f(κaHückel（厚雙電層，κa<<1）1Smoluchowski（薄雙電層，κa1）1.5Smoluchowskizeta（2）ζ=

Eq.

ζ=

Eq.Electrophoreticmobility(velocityperunitfieldstrength)iscommonlyexpressedinso-called“standardmobilityunits”,(μm·cm?V-1·s-1)whichareequivalentto(10-8m2?V-1·s-1).ZetapotentialiscommonlyexpressedinmV.Thisreportfollowstheseestablishedpractisesinordertoavoidverysmallnumericalvalues.Thetechniquesusedinthestudyonthediluteversionofthematerial,SRM1992/ERM-FD305,aresummarisedbelow.ElectrophoreticlightscatteringIntraditionalelectrophoreticlightscattering(ELS),theelectrophoreticmobilityofparticlessuspendedinasolutionismeasuredviatheDopplershiftofthescatteredlight.Similartodynamiclightscattering(DLS)experiments,amonochromaticcoherentincidentlightbeamilluminatessuspendedparticles.WhereasinDLSthesuspendedparticlesaremovingduetoBrownianmotion,inELStheparticlesarealsomovingduetoanappliedelectricfield,iftheyhaveanetcharge.Particleswillmovetowardseithertheanodeorthecathode,dependingonthesignoftheirnetcharge.Becauseofthismotion,thefrequencyandphaseofthescatteredlightwillbedifferentfromthatoftheincidentlight.ThisphenomenonisreferredtoastheDopplereffect.TherelationbetweentheDopplerfrequencyshiftofscatteredlightandparticleelectrophoreticmobility,μ,dependsontheopticalarrangementoftheinstrumentation[6].Forreferencebeam

電泳遷移率（單位場(chǎng)強(qiáng)下的速度）通常用所謂的“標(biāo)準(zhǔn)遷移率單位”表示，(μm?cm?V-1?關(guān)于材料稀薄版本（SRM1992/ERM?FD305）在傳統(tǒng)的電泳光散射(ELS)率。與動(dòng)態(tài)光散射(DLS)實(shí)驗(yàn)類似，單色相干入射光束照射懸浮粒子。而在DLS中，懸浮粒子由于布朗運(yùn)動(dòng)而運(yùn)動(dòng)，在ELS中，如果它們具有凈電荷，則粒子也會(huì)由于施加的電場(chǎng)而運(yùn)動(dòng)。粒子將向陽(yáng)極或陰極移動(dòng)，取決于其凈電荷的符號(hào)。由于這種運(yùn)動(dòng)，散射光的頻率和相位將與入射光的頻率和相位不同。這種現(xiàn)象被稱為多普勒效應(yīng)。μ之間的關(guān)系取決于儀器的光學(xué)排列[6]。ThispublicationThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-Forcross-beam

??=

Eq.

??=

Eq.

??= 4??????

Eq.

??= 4?????? Thispublicationisavailablefreeofchargefrom:Thispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260- laserwavelengthinvacuum electricfieldstrength(V?m-1orkg?mA-1?s- refractiveindexofthe anglebetweentheincidentlightandthescattered anglebetweenthescatteredlightandtheorientationoftheelectric anglebetweenthetwoManycommercialsystemsnowusephaseanalysislightscattering(PALS),whichmeasuresthephaseshiftbetweenlightscatteredfromthesampleandareferencebeam.Therateofchangeofphaseshiftbetweenthetwosignalsisproportionaltothevelocityoftheparticles.PALSismuchmoresensitivethanDoppler-basedtechniquesandallowsmeasurementathighersaltconcentrationswherethehighelectricfieldsrequiredforDoppleranalysiscanbedetrimentaltothesampleandgenerateresistiveheating.Inclosedcells,electroosmoticmotionoftheion-containingsolutionoccursconcurrentlywiththeelectrophoreticmotionoftheparticleswhenanelectricfieldisapplied.Thefluidmotionbiasestheapparentparticlemotion.Thetraditionalapproachtoaddressthisissuerequiredmeasuringtheparticlevelocityattheso-calledstationarypoint,ageometricallydefineddistancefromthesidewallsofacapillarycell,whereelectroosmoticmotioniszero.Today,mostELSinstrumentsavoidthisproblementirelybyusing“dipcells”,inwhichtheelectrodesareimmersedinacuvette,orbyusingamethodknownasfastfieldreversal.Inbothcases,electro-osmosisiseliminatedandtheunbiasedelectrophoreticmobilitycanbemeasuredatanylocationinthecellbetweentheanodeandcathode.Zetapotentialbyparticletrackinganalysis(Z-Z-PTAcombineslaserlightscatteringwithadigitalvideocamera.Thecamerarecordsthelightscatteredbytheparticlesthataremovingundertheelectricfield.Theelectricfieldcausesmotionofthesampleparticles(i.e.electrophoresis),andoftheaqueousmedium(i.e.electro-osmosis).ThePTAsoftwarerecordsthetotalapparentdriftvelocity,whichisasuperpositionofthesetwomotions,foreachtrackedparticle.Byobservingthetotalvelocityatdifferentdepthswithintheclosedsamplechamber,andassumingazeronetflowsummedovertheentirechamberdepth,itispossibletoseparatethesetwocomponents.Theelectrophoreticmobility(duetotheelectricforceontheparticles)canthereforebemeasuredforeveryparticletrackedbytheinstrumentsoftware.SelectionoftheGivenitsindustrialrelevanceandtheabilitytoremaincolloidallystableonatimescaleofyears,silicaparticleswereselectedasacandidatematerial.SRM1992/ERM-FD305wasproducedfromacommerciallyavailablesuspensionthatconsistedofsilicaparticlessuspendedinanundefinedaqueoussolutionofelectrolyte.ThedispersingsolutionwasexchangedbyatangentialflowfiltrationprocesstoaboratebufferatpH9withadefinedcomposition.SRM1992/ERM-FD305waspreparedataready-to-useconcentrationof1.5gkg-1forELSmeasurements.

?ω.........多普勒頻移(s-1)λ0............真空中的激光波長(zhǎng)(m) 電場(chǎng)強(qiáng)度802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupm-1或kg?mA-1?s-3)n............介質(zhì)的折射率802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupPALS)，它測(cè)量從樣品散射的光與參考光束之間的相位差。兩個(gè)信號(hào)之間相位差的變化率與粒子的速度成正比。PALSDopplerDoppler在封閉的細(xì)胞中，當(dāng)施加電場(chǎng)時(shí)，含有離子的溶液的電滲運(yùn)動(dòng)與粒子的電泳運(yùn)動(dòng)同時(shí)發(fā)生。流體運(yùn)動(dòng)使粒子的表觀運(yùn)動(dòng)產(chǎn)生偏差。傳統(tǒng)的解決方法需要在所謂的靜止點(diǎn)測(cè)量粒子速度，靜止點(diǎn)是從毛細(xì)管細(xì)胞的側(cè)壁幾何定義的距離，在該距離處電滲運(yùn)動(dòng)為零。如今，大多數(shù)ELS儀器通過(guò)使用“浸入式細(xì)胞轉(zhuǎn)的方法來(lái)完全避免這個(gè)問(wèn)題。在這兩種情況下，電滲都被消除，可以在陰陽(yáng)極之間的細(xì)胞中任何位置測(cè)量無(wú)偏的電泳遷移率。導(dǎo)致樣品粒子（即電泳）和水的介質(zhì)（即電滲）的運(yùn)動(dòng)。PTASRM1992/ERM?FD305是由一種商業(yè)可用的懸浮液制成的，該懸浮液由懸浮在未定義的電解pH9具有定義的成分。SRM1992/ERM?FD305ELS1.5gkg-1的即用濃度。Thispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-DesignoftheCRMThispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-AmaterialwasselectedforwhichtheSmoluchowskiapproximationapplies.Thisisnotstrictlynecessary,asthemeasuredvalueistheelectrophoreticmobility,butisusefulasmostusersreportzetapotential.ThestabilityandthehomogeneityofthematerialwereevaluatedthroughmeasurementsofelectrophoreticmobilityusingELS.ThecertifiedandadditionalmaterialinformationvalueswereestablishedbyacomparisonbetweendifferentlaboratorieswithdifferentmeasurementThecertifiedzetapotentialvalueanditsuncertaintyarecalculatedusingtheSmoluchowskirelation(Eq.2)andtheelectrophoreticmobilityvaluesreportedbythelaboratories.ThezetapotentialvaluesreporteddirectlybythelaboratoriesareprovidedinAnnexEforParticipantsProjectmanagementandEuropeanCommission,JointResearchCentre,DirectorateF–Health,ConsumersandReferenceMaterials,Geel,BE(accreditedtoISO17034forproductionofcertifiedreferencematerials,BELACNo.268-RM)NationalInstituteofStandardsandTechnology(NIST),Gaithersburg,USAEuropeanCommission,JointResearchCentre,DirectorateF–Health,ConsumersandReferenceMaterials,Geel,BE(accreditedtoISO17034forproductionofcertifiedreferencematerials,BELACNo.268-HomogeneityNationalInstituteofStandardsandTechnology(NIST),Gaithersburg,StabilityNationalInstituteofStandardsandTechnology(NIST),Gaithersburg,EuropeanCommission,JointResearchCentre,DirectorateF–Health,ConsumersandReferenceMaterials,Geel,BE(measurementsunderthescopeofISO/IEC17025accreditationBELACNo.268-Theparticipantsintheinterlaboratorycomparisonstudywere(inalphabeticalorder):AntonPaarGmbH,Graz,ATEuropeanCommission,JointResearchCentre,DirectorateF–Health,ConsumersandReferenceMaterials,Geel,BE(MeasurementsunderthescopeofISO/IEC17025accreditationBELACNo.268-FraunhoferInstitutfürKeramischeTechnologieandSysteme(IKTS),DresdenDE(MeasurementsunderthescopeofISO/IEC17025accreditation;TheDeutscheAkkreditierungsstelleGmbHN°.D-PL-11140-15-00)Horiba,Palaiseau,FRLGCLtd,Teddington,UK

1.3CRMSmoluchowskizetaELS802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbup參與者歐洲委員會(huì)，聯(lián)合研究中心，F(xiàn)BE（生產(chǎn)有證參ISO17034BELACNo268?RM）歐洲委員會(huì)，聯(lián)合研究中心，F(xiàn)BE（生產(chǎn)有證參ISO17034BELACNo268?RM）NISTStabilityNationalInstituteofStandardsandTechnology(NIST),Gaithersburg,FBE（測(cè)量范圍在ISO/IEC17025BELACNo268?TEST）AntonPaarGmbH歐洲委員會(huì)，聯(lián)合研究中心，F(xiàn)部門–健康、消費(fèi)者 參考材料，Geel，BE（ISO/IEC17025BELACNo268?TEST弗勞恩霍夫陶瓷技術(shù)與系統(tǒng)研究所（IKTS），Dresden，DE（ISO/IEC17025ND?PL?11140?15?00）Thispublicationisavailablefreeofchargefrom:Thispublicationisavailablefreeofchargefrom:/10.6028/NIST.SP.260-MoscowInstituteofPhysicsandTechnology,Moscow,NationalInstituteofStandardsandTechnology(NIST),Gaithersburg,USANationalMeasurementInstituteAustralia(NMIA),WestLindfield,AUNationalMetrologyInstituteofJapan(NMIJ),Tsukuba,JPNNationalPhysicalLaboratory(NPL),Teddington,UKOtsukaElectronics,Osaka,JPNPostnovaAnalyticsGmbH,Landsberg,DEWyattTechnology,SantaBarbara,USAMaterialprocessingandprocesscontrolOriginofthestartingmaterialandavailableThecolloidalsilicastartingmaterialAcesolWP4wassuppliedbyAceNanochem(RepublicofKorea).MaterialspecificationsforthestartingmaterialasprovidedbythemanufacturerarelistedinTable1.Inpreliminarystudiespriortocertification,anumberofmaterialpropertieswereThenominalSiO2(dry)massfractionwasdeterminedbyin-housemeasurementsat180gkg-1.SizeIntensityThescatteredlightintensity-weightedarithmeticmeanhydrodynamicparticlediameterwasconfirmedtoSizeIntensityFig1:Scatteredlightintensity-basedparticlesizedistributionofAcesolWP4obtainedby

PanalyticalInc.,Westborough,USAMicrotracInc.,Montgomeryville,美國(guó)國(guó)家標(biāo)準(zhǔn)與技術(shù)研究院（NIST），美國(guó)蓋瑟斯堡NMIA)，西林菲爾德，AU802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahc802-062.PS.TSIN/8206.01/gro.iod//:sptth:morfegrahcfoeerfelbaliavasinoitacilbupJPNPostnovaAnalyticsGmbHWyattTechnology材料加工與工藝控制OriginofthestartingmaterialandavailableAcesolWP4AceNanochem公司提供。制造商提供的起始材1SiO2180gkg-1SizeIntensityDLSSizeIntensity圖1：DLSAcesolWP4ParticlesizemeasurementsonasamplefromapreviousbatchofAcesolWP4wereperformedbyanindependentlaboratory(MVAScientificConsultants,Duluth,USA)usingtransmissionelectronmicroscopy(TEM).TEMgridsweredippedinasamplewhichhadbeendiluted2-foldwithdeionisedwater.ThepreparedtestspecimenswereimagedinaPhilipsCM120transmissionelectronmicroscopeoperatedatanaccelerationvoltageof100kV.AtypicalTEMmicrographisshowninFig.2.Twodistinctparticlepopulationscanbedistinguished:Onepopulationiscentredaround120nmwhilethesecondoneisaround30nm.Theparticleaspectratio,definedastheratioofthemajordiameter(length)totheminordiameter(width)ofafittedellipse,isclosetooneindicatinganear-sphericalmorphology.500500Fig2:TEMmicrographandnumber-basedarea-equivalentparticlesizedistributionofAcesolWP4silicaparticles(MVAScientificConsultants,Duluth,USA)Despitethepresenceofasmall-sizeparticlepopulation,thematerialwasselectedfortheproductionoftheCRMmaterial.Indeed,asvalueassignmentisbyELS,thenumberofsmallparticlesistoolowtoaffectthelightscatteredbythelargersizepopulation(intensitybasedIn-housecharacterizationwasperformedonthenewbatchofAcesolWP4receivedfortheproductionofthecandidatematerial(1:1000dilutionwithpurifiedwater)withafieldemissionscanningelectronmicroscope(SEM)JEOLJSM–7800F,operatedinbothconventionalSEMmodeandtransmission(TSEM)mode.TheSEMandTSEMmicrographs(Fig.3)show,aswiththeprevioussamplebatch,apopulationofparticles