《工业分析 Industrial Analysis》课件-旋光度产生原因及测定意义（双语）

项目八：常规物理常数与性能分析任务六：旋光度的测定旋光度产生原因及测定意义课程：工业分析中文Scenario8:PhysicalconstantsandperformancetestingTask6:DeterminationofopticalrotationThecausesandmeasurementsignificanceofopticalrotationCourse:IndustrialAnalysisEglish

一、旋光度产生原因1、光的振动光在传播过程中向各个方法振动中文一、ThecausesofopticalrotationLightvibratesinvariouswaysduringpropagation1.ThevibrationoflightEglish2、偏振光的产生偏振光:当把自然光通过某种介质后，在垂直于光传播方向的平面上，只在一个特定的方向上振动的光中文2.ThegenerationofpolarizedlightPolarizedlight:LightthatvibratesinaspecificdirectiononaplaneperpendiculartothedirectionoflightpropagationwhennaturallightpassesthroughacertainmediumPolarizingmirrorAnalyzerEglish

3、不对称碳原子化合物的认识

H

︱R－C－R′

︱CH3不对称碳原子手性碳原子具有旋光性中文

3.Understandingasymmetriccarbonatomcompounds

H

︱R－C－R′

︱CH3asymmetriccarbonatomchiralcarbonatomHavingopticalrotationEglish

4、基本概念

旋光性：偏振光通过具有手性异构的化合物溶液时，使偏振光的振动方向发生旋转的特性。

旋光度：偏振光通过旋光性物质之后，振动方向旋转的角度称为旋光度。

右旋体：能使偏振光的振动方向向右旋转的旋光性物质。

左旋体：能使偏振光的振动方向向左旋转的旋光性物质。中文

4.BasicconceptsOpticalactivity:Thecharacteristicofpolarizedlightrotatinginthedirectionofvibrationwhenitpassesthroughasolutionofcompoundswithchiralisomers.Opticalrotation:Theangleatwhichpolarizedlightrotatesinthedirectionofvibrationafterpassingthroughaopticallyactivesubstance.Right-handedbody:arotationalsubstancethatcanrotatethedirectionofpolaLeft-handedbody:arotationalsubstancethatcanrotatethevibrationdirectionofpolarizedlighttotheleft.Eglish

旋光度的大小主要决定于旋光性物质的分子结构，不同结构的物质对光的旋转能力是不一样的，另外物质使光旋转的角度也与溶液的浓度、液层厚度、入射偏振光的波长及测定时的温度等因素有关。因此旋光仪测定的旋光度并非特征物理常数，同一化合物测得的旋光度就有不同的值。因此，为了比较不同物质的旋光性能，提出了比旋光度的概念。中文

Themagnitudeofopticalrotationismainlydeterminedbythemolecularstructureofopticallyactivesubstances.Substanceswithdifferentstructureshavedifferentabilitiestorotatelight.Inaddition,theangleatwhichlightrotatesbysubstancesisalsorelatedtofactorssuchastheconcentrationofthesolution,thethicknessoftheliquidlayer,thewavelengthofincidentpolarizedlight,andthetemperatureduringmeasurement.Therefore,theopticalrotationmeasuredbyapolarimeterisnotacharacteristicphysicalconstant,andtheopticalrotationmeasuredbythesamecompoundhasdifferentvalues.Therefore,inordertocomparetheopticalrotationperformanceofdifferentsubstances,theconceptofspecificrotationwasproposed.Eglish

比旋光度一般规定以黄色钠光D线为光源，在20℃时，偏振光透过浓度为1g/mL、液层厚度为1dm旋光性物质的溶液时的旋光度，叫做比旋光度，用表示

纯液体的比旋光度溶液的比旋光度旋光度液体密度液体厚度溶液浓度中文

SpecificrotationTheopticalrotationgeneratedwhenpolarizedlightpassesthroughasolutionwithaconcentrationof1g/mLandaliquidlayerthicknessof1dmatatemperatureof20℃usingayellowsodiumlightD-lineasthelightsourceiscalledspecificrotationandisrepresentedby

SpecificrotationofpureliquidsSpecificrotationofsolution

opticalrotationLiquiddensityliquidlayerthicknesssolutionconcentrationEglish

二、测定意义1、定性鉴别：利用比旋光度例：称取一纯糖试样10.00g，用水溶解后，稀释为50.00mL。20℃时，用1dm旋光管，以黄色钠光测得旋光度为+13.3º。测得值与文献值对照，此糖为蔗糖中文

二、Determinationofsignificance1.Qualitativeidentification:usingspecificrotationExample:Weigh10.00

gofapuresugarsample,dissolveitinwater,anddiluteto50.00

mL.At20℃,theopticalrotationwasmeasuredtobe+13.3ºusinga1dmrotarytubeandyellowsodiumlight.Themeasuredvalueiscomparedwiththeliteraturevalue,andthissugarissucrose

Eglish

2、纯度或浓度测定例:称取蔗糖试样5.000g，用水溶解后，稀释为50.00mL，20℃时，用2dm旋光管，黄色钠光测得旋光度为+12.0º，试求蔗糖的纯度。已知蔗糖比旋光度为+66.50解（1）求试样溶液中蔗糖的浓度C中文

2、PurityorconcentrationdeterminationExample:Weigh5.000

gofsucrosesample,dissolveitinwateranddiluteitto50.00

mL.At20℃,usea2dmopticaltubeandyellowsodiumlighttomeasuretheopticalrotationas+12.0º.Trytodeterminethepurityofsucrose.Known