usp中缓冲溶液和标准溶液的详细配制方法

《usp中缓冲溶液和标准溶液的详细配制方法》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、usp中缓冲溶液和标准溶液的详细配制方法BUFFERSOLUTIONSThesuccessfulcompletionofmanyPharmacopeialtestsandassaysrequiresadjustmenttoormaintenanceofaspecifiedpHbytheadditionofbuffersolutions.InpHmeasurements,standardbuffersolutionsarerequiredforreferencepurposes.Forconvenience,thepreparationofthesesolutionsisinsomeinstan

2、cesdescribedinthesectionsinwhichtheiruseisspecified;i.e.,fiveseparatephosphatebuffersaredescribedunderAntibiotics--MicrobialAssays<81>,andseveralmiscellaneoussingle-purposesolutionsaredescribedintheindividualmonographs.Asolutionissaidtobebufferedifitresistschangesintheactivityofanionontheadditionofs

3、ubstancesthatareexpectedtochangetheactivityofthation.Buffersaresubstancesorcombinationsofsubstancesthatimpartthisresistancetoasolution.Bufferedsolutionsaresystemsinwhichtheionisinequilibriumwithsubstancescapableofremovingorreleasingtheion.Buffercapacityreferstotheamountofmaterialthatmaybeaddedtoasol

4、utionwithoutcausingasignificantchangeinionactivity.Itisdefinedastheratioofacidorbaseadded(ingram-equivalentsperliter)tothechangeinpH(inpHunits).Thecapacityofabufferedsolutionisadjustedtotheconditionsofuse,usuallybyadjustmentoftheconcentrationsofbuffersubstances.Buffersareusedtoestablishandmaintainan

5、ionactivitywithinnarrowlimits.Themostcommonsystemsareusedtoestablishhydrogen-ionactivityforthecalibrationofpHmeters,inthepreparationofdosageformsthatapproachisotonicity,inanalyticalprocedures,andtomaintainstabilityofvariousdosageforms.Buffersusedinphysiologicalsystemsarecarefullychosensoasnottointer

6、ferewithpharmacologicalactivityofthemedicamentornormalfunctionoftheorganism.Itisessentialthatbuffersusedinchemicalanalysisbecompatiblewiththesubstancedeterminedandthereagentsused.STANDARDBUFFERSOLUTIONS--StandardsolutionsofdefinitepHarereadilyavailableinbuffersolutionspreparedfromtheappropriatereage

7、nts.Inaddition,buffersolutions,buffertablets,andbuffersolidsmaybeobtainedfromcommercialsourcesinconvenientprepackagedform.Suchpreparationsareavailablefortheentireworkingrangeinpharmaceuticalanalysis,b