1、BRITISH STANDARD BS EN 1262:2003 Surface active agents Determination of pH value of solutions or dispersions The European Standard EN 1262:2003 has the status of a British Standard ICS 71.100.40 BS EN 1262:2003 This British Standard, was published under the authority of the Standards Policy and Stra
2、tegy Committee on 25 November 2003 BSI 25 November 2003 ISBN 0 580 42974 1 National foreword This British Standard is the official English language version of EN 1262:2003. It supersedes BS EN 1262:1996 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee
3、CII/34, Methods of test for surface active agents, which 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 doc
4、ument may be found in the BSI Catalogue under the section 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
5、. Users are responsible for its 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 international/European committee any enquiries on the interpretation, or proposals for c
6、hange, 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 front cover, the EN title page, pages 2 to 9 and a back cover. The BSI copyright notice displayed in thi
7、s document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN1262 October2003 ICS71.100.40 SupersedesEN1262:1996 Englishversion SurfaceactiveagentsDeterminationofpHvalueofsolutionsor dispersions Age
8、ntsdesurfaceDterminationdelavaleurdupHdes solutionsoudesdispersions GrenzflchenaktiveStoffeMessungdespHWertesvon LsungenoderDispersionen ThisEuropeanStandardwasapprovedbyCENon8September2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope
9、 an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagem
10、adebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,
11、Netherlands,Norway,Portugal,Slovakia,Spain,Sweden,SwitzerlandandUn ited Kingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnat
12、ionalMembers. Ref.No.EN1262:2003EEN1262:2003(E) 2 Contents page Foreword3 1 Scope 4 2 Termsanddefinitions. .4 3 Principle4 4 Reagents.4 5 Apparatus .4 6 Preparationofproductsolutionsordispersions . 5 7 Procedure .6 8 Expressionofresults . .6 9 Precision.6 10 Testreport 7 AnnexA (informative) Ringtes
13、tresults . .8EN1262:2003(E) 3 Foreword Thisdocument(EN1262:2003)hasbeenpreparedbyTechnicalCommitteeCEN/TC276“Surfaceactiveagents”, thesecretariatofwhichisheldbyAFNOR. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbyApril2
14、004,andconflictingnationalstandardsshallbewithdrawnatthelatestby April2004. ThisdocumentsupersedesEN1262:1996. SignificanttechnicaldifferencesbetweenthiseditionandEN1262:1996areasfollows: a) additionofthespecificationofwateranditspreparationin4.1; b) modificationoftheaccuracyofthepHmeterin5.1; c) in
15、troductionoftheuseofsodiumchloridesolutionin6.1forsolutionsoflowconductivity; d) introductionofapossibilityin6.2.1forsolutionAtoreplaceamassfractionof10%activemattersolution; e) introductionofnotesin7.2toindicatethepossibilitytoavoidtheabsorptionofCO 2 andtoaddfewdropsof dilutedsolutionofsodiumchlor
16、ideforthemeasurementofthepHofnonionicsurfaceactiveagents. AnnexAisinformative. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Hungary,Ic
17、eland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal, Slovakia,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN1262:2003(E) 4 1Scope ThisEuropeanStandardspecifiesamethodforthedeterminationofpHvalueofsolutionsordispersionsofsurface activeagentsandgivesamethodfortheirpreparation. Themethodis
18、applicabletoaqueoussolutionscontaininganionic,cationicandnonionicsurfaceactiveagents, ampholyticsurfaceactiveagentsandproductsinsolutioncontainingsurfaceactiveagents. 2 Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermanddefinitionapply. 2.1 activematter allofthesurfaceactive
19、agentsresponsibleforaspecifiedactivityinaformulation 3Principle ThepHvalueofthesamplesolutionisdeterminedbypotentiometricmeasurementusingaspecificelectrodeand commercialpHmeter. 4Reagents Duringthedetermination,unlessotherwisespecified,useonlyreagentsofrecognizedanalyticalgradewhichhave beencheckedi
20、nadvanceastonotinterferewiththeresults. 4.1 Water,deionisedwaterfromwhichcarbondioxidehasbeenremovedandhavingaconductivitynot exceeding1mS/mat25CandapHvaluebetween6,0and7,0orwaterofequivalentpurity. Toremovecarbondioxidefromthewateritshallbeboiledduringnotlessthan10min.Becausewaterrapidly absorbsaga
21、inCO 2 ,itshallbeallowedtocooldowninaflaskthathasatubefilledwithsodalimeinitsneck. ThepHvalueofthewatershallbemeasuredbyadditionofafewdropsofdilutesodiumchloride(4.4)inorderto increasetheconductivity. 4.2 Standardbuffersolutions, twosolutionswhichbrackettheexpectedpHvalueofthesamplesolution,for adju
22、stingthepHmeter. 4.3 Ethanolwithavolumefractionof96%, todetermineitssuitability,ethanolismixedwithdeionisedwater (4.1),inaratioof50:50( m/m);thepHvalueshallbebetween6,0and7,0,otherwiseamoresuitableethanol gradeshallbeused. 4.4 Sodiumchloride, w (NaCl)=10%(aqueoussolution). 5Apparatus Ordinarylaborat
23、oryapparatusandthefollowing. 5.1 pHmeter, withareadingresolutionof0,01pH,orbetter,comprisingapotentiometricunit,areference electrodeandanelectrodewhichissensitivetohydrogenions. NOTE CombinedelectrodesofglassandcalomelorAg/Ag+arecommerciallyavailable.Theyshouldbestored,cleaned andconditionedaccordin
24、gtothemanufacturersinstructions.EN1262:2003(E) 5 6 Preparationofproductsolutionsordispersions 6.1General Mostsurfaceactiveagentsformcleardilutesolutionsinwater. Surfaceactiveagentswhichdonotformaclearsolutioninwaterarefirstdissolvedinethanolandthenmixedwith water;thisproceduresometimesproducesdisper
25、sionswhichcreamafteracertaintime,i.e.formtwophases. Incaseofnonionicsurfaceactiveagents,afewdropsofsodiumchloride(4.4)shallbeaddedinordertoincrease theconductivityandhencethequalityofthemeasurement. Theconcentrationofthesolutiontobetestedhastobeclearlyspecified.Becauseatverylowsurfaceactiveagent con
26、centrationsreadingstabilityproblemsmayarise,suchsituationsaretobeavoided.Threenonlimitative situationsaredescribedin6.2and6.3. 6.2 Watersolubleproducts 6.2.1 SolutionA:massfractionof1%activematterinwater Weigh,tothenearest0,01g,atestportioncorrespondingto1gactivematterintoa150mlbeakerandmakeup to100
27、,00gsolutionwithwater(4.1).Ifnecessary,warmtonotmorethan50Ctoassistdissolutionandcoolto roomtemperature. Manysurfaceactiveagentsrequiretousesolutionswithamassfractionof10%activematterinwaterinorderto obtaingoodreproducibilityinwhichcasereplacesolutionAbyamassfractionof10%activemattersolution,i.e. we
28、ighatestportioncorrespondingto10gactivematterintoa150mlbeakerandmakeupto100,00gsolution withwater(4.1). 6.2.2 SolutionB:massfractionof5%solutioninwater Weigh,tothenearest0,01g,atestportionof5gintoa150mlbeakerandmakeupto100,00gsolutionwith water(4.1).Ifnecessary,warmtonotmorethan50Ctoassistdissolutio
29、nandcooltoroomtemperature. 6.3 Sparinglywatersolubleorwaterinsolubleproducts SolutionC: massfractionof 5%sampleinethanol/watermixture Weigh,tothenearest0,01g,atestportionof5gintoa150mlbeakerandadd47,5gethanol(4.3).Ifnecessary, warmtonotmorethan50Ctoassistdissolution.Add47,5gwater(4.1)andcooltoroomte
30、mperature. NOTE Forwaterinsolublesamplestheadditionofwaterproducesafinelydispersedprecipitate. Ifrequiredbyacustomerorproductspecification,thesolventorthequantityoftestportionusedtoprepare solutionsA,BandCmaybedifferentfromthosespecifiedin6.2and6.3.Inthiscasethesolventandthe concentrationofthesample
31、solutionusedshallbespecifiedinthetestreport. 6.4 Highlyconcentratedformulationsofsurfaceactiveagents Concerningmeasurementsinhighlyconcentratedsolutionsofsurfaceactiveagentsormoltenproductstheycan onlybecomparedifallparametersandtestconditionsaredefined. Athighconcentrationsthemeasurementsobtaineddo
32、notcorrespondtoscientificpHdefinition.EN1262:2003(E) 6 7Procedure 7.1 AdjustmentofthepHmeter AdjustthepHmeter(5.1)accordingtothemanufacturersinstructionsusingthetwostandardbuffersolutions(4.2). 7.2Determination Preparetwodifferentsolutionsofthesamplesolution(A,BorC)toenableduplicatemeasurementstobec
33、arried out. Washtheelectrodesfirstwithwater(4.1)andthenwithalittleofoneportionofthesamplesolution.Immersethe electrodesinthefirstsamplesolution,stirslowly.IfusingapHmeterwhichhasthefacility,setthepHmeterto recordthestabilisedvalue. NOTE1 IfthepHmeterdoesnothavethisfacility,thereadingshouldbenoted10s
34、afterastablevaluehasbeenachieved. Removetheelectrodesandrinsewithalittleofthesecondsamplesolution.Immersetheelectrodesinthesecond samplesolutionandrepeatthepHmeasurement. Ifthetwomeasurementsdifferbymorethan0,1pHunit,repeatthewholetest,andifthesituationpersists,check theelectrodeandthepHmeter. Carry
35、outallpHmeasurementsatatemperatureintherangefrom20Cto25C. Ifthesampleistobemeasuredatatemperaturenotbetween20Cand25C,thetemperatureknobofthe instrumenthastoberesetatthesampletemperature,andthiscircumstancehastobereported. NOTE2 Inthecaseofcationicsurfaceactiveagents,itisadvisabletocheckthepHmeteraft
36、ereachmeasurement,and readjustifnecessary. NOTE3 WhenmeasuringthepHvaluetheabsorptionofatmosphericcarbondioxideshouldbeavoided. NOTE4 AdditionofafewdropsofadilutesolutionofsodiumchloridefacilitatesthemeasurementofthepHofnonionic surfaceactiveagents. 8 Expressionofresults Calculatethemeanvalueofthetw
37、opHvaluereadingstothenearest0,1pHunitatthetesttemperature. 9Precision 9.1 Repeatabilitylimit Theabsolutedifferencebetweentwoindependentsingletestresults,obtainedusingthesamemethodonidentical testmaterialinthesamelaboratorybythesameoperatorusingthesameequipmentwithinashortintervaloftime, willnotexcee
38、dtherepeatabilitylimit, r, inmorethan5%ofcases. PrecisiondataaregiveninannexA.EN1262:2003(E) 7 9.2Reproducibility limit Theabsolutedifferencebetweentwoindependentsingletestresults,obtainedusingthesamemethodonidentical testmaterialindifferentlaboratoriesbydifferentoperatorsusingdifferentequipment,wil
39、lnotexceedthe reproducibilitylimit, R,inmorethan5%ofcases. PrecisiondataaregiveninannexA. Ifareproducibilitylimitoflessthan0,3pHunitisaimedfor,allrelevantinfluencingparameterssuchastemperature compensation,electrodeslope,calibrationmethod,alkalierror/aciderror,dilutionfactorshallbeveryprecisely desc
40、ribed. 10 Testreport Thetestreportshallincludethefollowing: a) allinformationnecessaryforthecompleteidentificationofthesample; b) thesolventcompositionused(ifnotwater),andsurfaceactiveagentconcentration; c) thetwostandardbuffersolutionsusedfortheadjustmentofthepHmeter; d) theexacttemperatureofthemea
41、surements,withlimitdeviationof 1C; e) theageofthesolutionordispersionatthetimeofconductingthemeasurements; f) theappearanceofthesolutionordispersion(clear,cloudy,creamy)atthetimeofconductingthe measurements; g) thetestresults; h) anyoperationnotincludedinthisstandardorregardedasoptional,aswellasanyi
42、ncidentswhichcanhave affectedtheresults.EN1262:2003(E) 8 Annex A (informative) Ringtestresults TheringtestwascarriedoutfromAEN/CTN55Bin2001.ThesymbolsusedintableA.1meanthefollowing: A:Alkylethersulfate,70%(activematter).Samplesolutionsof2%activematter. B:Alkylethersulfatealkaline26%(activematter). C
43、:Alkylethersulfatealkaline26%(activematter).Samplesolutionsof1%activematter. D:FattyalcoholethoxylatedalkylchainC 12 C 14 with4EO.Samplesolutionsof5%activematter. E:Cocamidopropylbetaine30%(activematter). F:Cocamidopropylbetaine30%(activematter).Samplesolutionsof1%activematter. G:Esterquat.Samplesolutionof5%activematter. H:Alkylethersulfatealkaline26%(activematter).EN1262:2003(E) 9 TableA
