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ID:39441930
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页数:3页
时间:2019-07-03
《英国药典有关原子吸收和发射部分的附录介绍》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、Thesetechniquesareusedtodeterminetheconcentrationofcertainmetallicionsbymeasuringtheintensityofemissionorabsorptionoflightataparticularwavelengthbytheatomicvapouroftheelementgeneratedfromthesubstance,forexample,byintroducingasolutionofthesubstanceintoaflame.ATOMICEMISSIONS
2、PECTROMETRY(Ph.Eur.method2.2.22)Atomicemissionspectrometryisamethodfordeterminingtheconcentrationofanelementinasubstancebymeasuringtheintensityofoneoftheemissionlinesoftheatomicvapouroftheelementgeneratedfromthesubstance.Thedeterminationiscarriedoutatthewavelengthcorrespon
3、dingtothisemissionline.ApparatusThisconsistsessentiallyofanatomicgeneratoroftheelementbeingdetermined(flame,plasma,arc,etc),amonochromatorandadetector.Ifthegeneratorisaflame,wateristhesolventofchoiceforpreparingtestandreference[standard]solutions,althoughorganicsolventsmay
4、alsobeusedifprecautionsaretakentoensurethatthesolventdoesnotinterferewiththestabilwityoftheflame.MethodOperateanatomicemissionspectrometerinaccordancewiththemanufacturer'sinstructionsattheprescribedwavelengthsetting.Introduceablanksolutionintotheatomicgeneratorandadjustthe
5、instrumentreadingtozero.Introducethemostconcentratedreference[standard]solutionandadjustthesensitivitytogiveasuitablereading.Determinationsaremadebycomparisonwithreference[standard]solutionswithknownconcentrationsoftheelementtobedeterminedeitherbythemethodofdirectcalibrati
6、on(MethodI)orthemethodofstandardadditions(MethodII).UseMethodIunlessotherwisedirected.MethodI:MethodofdirectcalibrationPreparethesolutionofthesubstancetobeexamined(testsolution)asprescribed.Preparenotfewerthanthreereference[standard]solutionsoftheelementbeingdeterminedthec
7、oncentrationsofwhichspantheexpectedvalueinthetestsolution.Anyreagentsusedinthepreparationofthetestsolutionareaddedtothereference[standard]solutionsinthesameconcentration.Introducethetestsolutionandeachreference[standard]solutionintotheinstrumentatleastthreetimesandrecordth
8、esteadyreading.Rinsetheapparatuswithblanksolutioneachtimeandascertainthatthereadingreturn
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