美国药典USP32 重金属part 中文翻译Word格式.docx

美国药典USP32 重金属part 中文翻译Word格式.docx

《美国药典USP32 重金属part 中文翻译Word格式.docx》由会员分享，可在线阅读，更多相关《美国药典USP32 重金属part 中文翻译Word格式.docx（6页珍藏版）》请在冰豆网上搜索。

SpecialReagents

LeadNitrateStockSolution—Dissolve159.8mgofleadnitratein100mLofwatertowhichhasbeenadded1mLofnitricacid,thendilutewithwaterto1000mL.Prepareandstorethissolutioninglasscontainersfreefromsolubleleadsalts.

StandardLeadSolution—Onthedayofuse,dilute10.0mLofLeadNitrateStockSolutionwithwaterto100.0mL.EachmLofStandardLeadSolutioncontainstheequivalentof10µ

goflead.Acomparisonsolutionpreparedonthebasisof100µ

LofStandardLeadSolutionpergofsubstancebeingtestedcontainstheequivalentof1partofleadpermillionpartsofsubstancebeingtested.

MethodI

pH3.5AcetateBuffer—Dissolve25.0gofammoniumacetatein25mLofwater,andadd38.0mLof6Nhydrochloricacid.Adjust,ifnecessary,with6Nammoniumhydroxideor6NhydrochloricacidtoapHof3.5,dilutewithwaterto100mL,andmix.

StandardPreparation—Intoa50-mLcolor-comparisontubepipet2mLofStandardLeadSolution（20µ

gofPb）,anddilutewithwaterto25mL.UsingapHmeterorshort-rangepHindicatorpaperasexternalindicator,adjustwith1Naceticacidor6NammoniumhydroxidetoapHbetween3.0and4.0,dilutewithwaterto40mL,andmix.

TestPreparation—Intoa50-mLcolor-comparisontubeplace25mLofthesolutionpreparedforthetestasdirectedintheindividualmonograph;

or,usingthedesignatedvolumeofacidwherespecifiedintheindividualmonograph,dissolveinanddilutewithwaterto25mLthequantity,ing,ofthesubstancetobetested,ascalculatedbytheformula:

2.0/（1000L）,

inwhichListheHeavymetalslimit,asapercentage.UsingapHmeterorshort-rangepHindicatorpaperasexternalindicator,adjustwith1Naceticacidor6NammoniumhydroxidetoapHbetween3.0and4.0,dilutewithwaterto40mL,andmix.

MonitorPreparation—Intoathird50-mLcolor-comparisontubeplace25mLofasolutionpreparedasdirectedforTestPreparation,andadd2.0mLofStandardLeadSolution.UsingapHmeterorshort-rangepHindicatorpaperasexternalindicator,adjustwith1Naceticacidor6NammoniumhydroxidetoapHbetween3.0and4.0,dilutewithwaterto40mL,andmix.,

Procedure—ToeachofthethreetubescontainingtheStandardPreparation,theTestPreparation,andtheMonitorPreparation,add2mLofpH3.5AcetateBuffer,thenadd1.2mLofthioacetamide–glycerinbaseTS,dilutewithwaterto50mL,mix,allowtostandfor2minutes,andviewdownwardoverawhitesurface*:

thecolorofthesolutionfromtheTestPreparationisnotdarkerthanthatofthesolutionfromtheStandardPreparation,andthecolorofthesolutionfromtheMonitorPreparationisequaltoordarkerthanthatofthesolutionfromtheStandardPreparation.[NOTE—IfthecoloroftheMonitorPreparationislighterthanthatoftheStandardPreparation,useMethodIIinsteadofMethodIforthesubstancebeingtested.]

MethodII

NOTE—Thismethoddoesnotrecovermercury.

pH3.5AcetateBuffer—PrepareasdirectedunderMethodI.

StandardPreparation—Pipet4mLoftheStandardLeadSolutionintoasuitabletesttube,andadd10mLof6Nhydrochloricacid.

TestPreparation—Useaquantity,ing,ofthesubstancetobetestedascalculatedbytheformula:

4.0/（1000L）,

inwhichListheHeavymetalslimit,asapercentage.Transfertheweighedquantityofthesubstancetoasuitablecrucible,addsufficientsulfuricacidtowetthesubstance,andcarefullyigniteatalowtemperatureuntilthoroughlycharred.（Thecruciblemaybelooselycoveredwithasuitablelidduringthecharring.）Addtothecarbonizedmass2mLofnitricacidand5dropsofsulfuricacid,andheatcautiouslyuntilwhitefumesnolongerareevolved.Ignite,preferablyinamufflefurnace,at500to600,untilthecarboniscompletelyburnedoff（nolongerthan2hours）.Ifcarbonremains,allowtheresiduetocool,addafewdropsofsulfuricacid,evaporate,andigniteagain.Cool,add5mLof6Nhydrochloricacid,cover,anddigestonasteambathfor10minutes.Cool,andquantitativelytransferthesolutiontoatesttube.Rinsethecruciblewithasecond5-mLportionof6Nhydrochloricacid,andtransfertherinsingtothetesttube.

MonitorPreparation—Pipet4mLoftheStandardLeadSolutionintoacrucibleidenticaltothatusedfortheTestPreparationandcontainingaquantityofthesubstanceundertestthatisequalto10%oftheamountrequiredfortheTestPreparation.Evaporateonasteambathtodryness.Igniteatthesametime,inthesamemufflefurnace,andunderthesameconditionsusedfortheTestPreparation.Cool,add5mLof6Nhydrochloricacid,cover,anddigestonasteambathfor10minutes.Cool,andquantitativelytransfertoatesttube.Rinsethecruciblewithasecond5-mLportionof6Nhydrochloricacid,andtransfertherinsingtothetesttube.

Procedure—AdjustthesolutionineachofthetubescontainingtheStandardPreparation,theTestPreparation,andtheMonitorPreparationwithammoniumhydroxide,addedcautiouslyanddropwise,toapHof9.Cool,andadjustwithglacialaceticacid,addeddropwise,toapHof8,thenadd0.5mLinexcess.UsingapHmeterorshort-rangepHindicatorpaperasexternalindicator,checkthepH,andadjust,ifnecessary,with1Naceticacidor6NammoniumhydroxidetoapHbetween3.0and4.0.Filter,ifnecessary,washingthefilterwithafewmLofwater,intoa50-mLcolor-comparisontube,andthendilutewithwaterto40mL.Add2mLofpH3.5AcetateBuffer,thenadd1.2mLofthioacetamide–glycerinbaseTS,dilutewithwaterto50mL,mix,allowtostandfor2minutes,andviewdownwardoverawhitesurface*:

thecolorofthesolutionfromtheTestPreparationisnotdarkerthanthatofthesolutionfromtheStandardPreparation,andthecolorofthesolutionfromtheMonitorPreparationisequaltoordarkerthanthatofthesolutionfromtheStandardPreparation.[NOTE—IfthecolorofthesolutionfromtheMonitorPreparationislighterthanthatofthesolutionfromtheStandardPreparation,proceedasdirectedforMethodIIIforthesubstancebeingtested.]

MethodIII

StandardPreparation—Transferamixtureof8mLofsulfuricacidand10mLofnitricacidtoaclean,dry,100-mLKjeldahlflask,andaddafurthervolumeofnitricacidequaltotheincrementalvolumeofnitricacidaddedtotheTestPreparation.Heatthesolutiontotheproductionofdense,whitefumes;

cool;

cautiouslyadd10mLofwater;

and,ifhydrogenperoxidewasusedintreatingtheTestPreparation,addavolumeof30percenthydrogenperoxideequaltothatusedforthesubstancebeingtested.Boilgentlytotheproductionofdense,whitefumes.Againcool,cautiouslyadd5mLofwater,mix,andboilgentlytotheproductionofdense,whitefumesandtoavolumeof2to3mL.Cool,dilutecautiouslywithafewmLofwater,add2.0mLofStandardLeadSolution（20µ

gofPb）,andmix.Transfertoa50-mLcolor-comparisontube,rinsetheflaskwithwater,addingtherinsingtothetubeuntilthevolumeis25mL,andmix.

TestPreparation—Unlessotherwiseindicatedintheindividualmonograph,useaquantity,ing,ofthesubstancetobetestedascalculatedbytheformula:

2.0/（1000L）,

inwhichListheHeavymetalslimit,asapercentage.

Ifthesubstanceisasolid—Transfertheweighedquantityofthetestsubstancetoaclean,dry,100-mLKjeldahlflask.[NOTE—A300-mLflaskmaybeusedifthereactionfoamsexcessively.]Clamptheflaskatanangleof45,andaddasufficientquantityofamixtureof8mLofsulfuricacidand10mLofnitricacidtomoistenthesubstancethoroughly.Warmgentlyuntilthereactioncommences,allowthereactiontosubside,andaddportionsofthesameacidmixture,heatingaftereachaddition,untilatotalof18mLoftheacidmixturehasbeenadded.Increasetheamountofheat,andboilgentlyuntilthesolutiondarkens.Cool,add2mLofnitricacid,andheatagainuntilthesolutiondarkens.Continuetheheating,followedbyadditionofnitricaciduntilnofurtherdarkeningoccurs,thenheatstronglytotheproductionofdense,whitefumes.Cool,cautiouslyadd5mLofwater,boilgentlytotheproductionofdense,whitefumes,andcontinueheatinguntilthevolumeisreducedtoafewmL.Cool,cautiouslyadd5mLofwater,andexaminethecolorofthesolution.Ifthecolorisyellow,cautiouslyadd1mLof30percenthydrogenperoxide,andagainevaporatetothe