2023学年完整公开课版DeterminationofpHofglucoseinjection

PharmaceuticalanalysisDeterminationofpHofglucoseinjectionDeterminationofpHofglucoseinjectionAuthor:GanLinling1.Overview(1)GlucoseinjectionMedicinediluentReplenishheatandbodyfluids.1.OverviewpHshouldbe3.2-6.51.OverviewLEI-CIPHS-3CprecisionpHmeter2.Operationsteps(1)Preparationofstandardbuffersolution(2)Preparationofinstrument(3)Calibrationofacidimeter(4)Applicationofacidimeter(5)Precautionsforcorrectionofacidimeter(6)MeasurementofpH2.OperationstepsCalibratethePHmeterwithstandardbuffersolutionbeforeuse.Standardbuffersolution:Itispreparedwithcorrespondingchemicalreagentsandpurewateraccordingtorequirements,andhasrelativelystablepHvalue.Biphthalate:pH=4.01at25°CDisodiumhydrogenphosphateandmonopotassiumphosphate:pH=6.86at25°CBorax:pH=9.18at25°C(1)Preparationofstandardbuffersolution2.OperationstepsWeigh10.12gofpotassiumhydrogenphthalate(KHC8H4O4)driedat110―130℃for2-3handdissolveitwateranddiluteitto1Linavolumetricflask.1)Diphthalate(pH=4.01)Weigh3.388gofpotassiumdihydrogenphosphate(KH2PO4)driedat110―130℃for2-3hand3.533gofdisodiumhydrogenphosphate(Na2HPO4)respectivelyanddissolvetheminwateranddilutethemto1Linavolumetricflask.2)Phosphatebuffersolution(pH=6.86)2.OperationstepsInordertomakethecrystalhaveacertaincomposition,weigh3.80gofborax(Na2B4O710H20)putinadryertogetherwithsaturatedsodiumbromide(orsodiumchlorideaddedwithsucrose)solution(roomtemperature)tobalancefortwodaysandnightsandthendissolveitinwateranddiluteittolLinavolumetricflask.3)Boraxbuffersolution(pH=9.18)2.Operationsteps1)Turnonandpreheattheinstrumentfor20min;2)AdjusttopHrange;(2)Preparationofinstrument2.Operationsteps1)Adjustthetemperaturecompensationtothecorrespondingtemperaturevalue;2)Adjustthesloperatecompensationto100%;3)Washtheelectrodewithdistilledwateranddryitwithfilterpaper;(3)CalibrationofacidimeterCleaningofelectrodeduringuseDryitwithfilterpaperortissue.Donotwipetheglassfilmhard2.Operationsteps(4)Applicationofacidimeter1)Inserttheelectrodeintothe6.86buffersolution;2)Adjustthelocatingbuttontothereadingof6.86;3)Washtheelectrodewithdistilledwateranddryitwithfilterpaper;4)Inserttheelectrodeintothe4.00buffersolution(standardalkalinesolutionformeasurementofalkalinesubstance);5)Adjustthesloperatecompensationbuttontothereadingof4.00;Repeattheabovestepsuntiltheinstrumentstabilizes.2.OperationstepsLevelrequirementsThelowestlevelofthesolutiontobedeterminedshouldbehigherthanthatatcalomelelectrode(redarrow)SolutiontobedeterminedPlasticprotectivecoverGlasselectrodeCalomelelectrodeReplenishingsolutionholeCompositeelectrodeLowestlevel2.Operationsteps(5)PrecautionsforcorrectionofacidimeterIftheinstrumentisnotturnedoff,itcanbeusedfordeterminationcontinuously,butonceitisturnedoff,itmustbecalibrated.Itmustbecalibratedonceevery12hoursevenifitisnotturnedoff.2.Operationsteps(6)MeasurementofpH1)Washtheelectrodewithdistilledwaterandthenflushitwithsolutiontobedeterminedanddryitwithfilterpaper;2)Inserttheelectrodeintothesolutiontobedetermined,shakethebeakerslightlyandthenreadthevalueandmakearecord.Carryouttheparalleldeterminationforthreetimes.2.OperationstepsTakeouttheelectrode,cleanit,andsoakitinpurifiedwaterafterdryingitwithfilterpaper.Ifitisnotusedforalongtime,theglassprobepartofthecompositeelectrodeshouldbesleevedinaplasticsleevecontaining3mol/Lpotassiumchloridesolution;BuffersolutionwithpH=7or4canbeusedforshort-termpreservation3.Experimentalthinking(