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1、▲CelluloseAcetateCelluloseacetate.Cellulose,diacetate[9035-69-2].Cellulose,triacetate[9012-09-3].»CelluloseAcetateispartiallyorcompletelyacetylatedcellulose」tcontainsnotlessthan29.0percentandnotmorethan44.8percent,byweight,ofacetyl(C2H3O)groups,calculatedonthedriedba
2、sis」tsacetylcontentisnotlessthan90.0percentandnotmorethan110・0percentofthatindicatedonthelabel.醋酸纤维素是部分或全部乙酰化的纤维素。按干燥品计含乙酰基29.0%〜44.8%,乙酰基含量应为标示量的90.0%〜110.0%。Packagingandstorage—Preserveintightcontainers.包装与储存密闭储存Labeling—Thelabelingstatesthenominalpercentagecontent
3、ofacetyl.标签一一注明乙酰基的标示含量USPReferencestandards〈11〉一USPCellulose/Ace朽feRS.Identification—PrepareasolutionofCelluloseAcetate(1in10),previouslydried,indioxane.Spread1dropofthesolutiononasodiumchlorideplate,placeasecondsodiumchlorideplateoverit,andspreadthespecimenbetweent
4、heplates.Separatetheplates,heatthembothat105Qfor1hour,andreassemblethedriedplates:theIRabsorptionspectrumexhibitsmaximaonlyatthesamewaveIengthsasthatofasimilarpreparationofUSPCelluloseAcetateffS,treatedinthesamemanner.鉴别一一Lossondrvina〈731〉—Dryitat105Qfor3hours:itlose
5、snotmorethan5.0%ofitsweight・干燥失重一一在105°C干燥3小时减失重量不得过5.0%,Residueoniqnition〈281〉:notmorethan0.1%.炽灼残渣Heavvmetals,/Vtef/?od//〈231〉:0.001%.重金屈10ppmFreeacid—Transferabout5g,accuratelyweighed,toa250-mLflask.Add150mLoffreshlyboiled,cooledwater,insertthestopperintotheflask,
6、swirlthesuspensiongently,andallowittostandfor3hours.Filterthroughpaper,andwashtheflaskandthefilterwithwater,addingthesewashingstothefiltrate.AddphenoIphthaleinTS,andtitratethecombinedfiltrateandwashingswith0.01NsodiumhydroxideVS.Calculatethepercentageoffreeacidinthep
7、ortionofCelluloseAcetatetakenbytheformula:0.06005/l/W,inwhichAisthevolume,inmL,of0.01Nsodiumhydroxideconsumed;andl/l/istheweight,ing,oftheCelluloseAcetatetaken,calculatedonthedriedbasis.Notmorethan0.1%,calculatedasaceticacid,isfound・游离酸一一取本品约5g,精密称定，置250ml量瓶中，加新沸过的冷水
8、150ml,盖上塞子，缓慢使成旋涡状，保持3小时。用滤纸过滤，用水冲洗量瓶和滤纸,合并滤液。滴加酚馭指示液，用0.01N的氢氧化钠滴定液滴定至终点，用下而的公式计算醋酸纤维素屮游离酸的百分数:0.06005A/W,其中A为消耗的0.01N氢氧化钠的体积(ml),
