上海大學(xué)儀器分析化學(xué)英語(yǔ)版

InstrumentalAnalysisShanghaiUniversityContentsIntroductionIntroductiontoOpticalMethods

AtomicEmissionSpectroscopyAtomicAbsorptionSpectroscopy

TheAbsorptionofRadiation:UltravioletandVisible

MolecularLuminescence:FluorometryandphosphorimetryTheAbsorptionofRadiation:Infrared

IntroductiontoElectrochemicalMethods

Potentiometry

PolarographyIntroductiontoInterphaseSeparations

GasChromatographyLiquidChromatography

Chapter1

Introduction

DefinitionofInstrumentalAnalysisClassificationFunctionImportantConsiderations

1.1.The

DefinitionofInstrumental

Analysis

Thescienceandart

ofdeterminingthecompositionofmaterials

with

theinstrumentalmethods

basedon

aphysicalpropertycharacteristic

ofaparticularelementorcompound

ChemicalInformation

observableSignalbydeterminationof

physicalproperties1.2.

PhysicalPropertiesUsefulinInstrumentalAnalysis1.

InteractionofRadiantEnergywithMatter2.

ElectricalorElectrochemicalProperties3.

InterphaseSeparation4.Other

Properties

MechanicalProperties

ThermalProperties

NuclearProperties

ExtensiveProperties1.3.

ClassificationofMainInstrumentalMethods

1.

OpticalMethods

Atomic:

AbsorptionSpectroscopy, Emission,Spectroscopy FluorescenceSpectroscopy

Molecular:

UV-Vis.Spectrophotometry IRSpectroscopy2.

ElectrochemicalMethods Potentiometry Polarography Voltammetry3.

Chromatography GasChromatography LiquidChromatography1.4

BasicFunctionofInstrumentationSignalGeneratorsInputTransducersSignalTransformationModulesOutputTransducers1.5

MajorAreasofanInstrumentalMethodHowthemethod“works”AdvantagesandlimitationsofthemethodIllustrativeinstrumentationApplicationsProblemsBibliographyChapter2

IntroductiontoOpticalMethods

TheNatureofRadiantEnergySpectralRegionsInteractionofRadiationwithAtomandMoleculePracticalSourcesofRadiationSpectrographandMonochromator2.1

TheNatureofRadiantEnergyTheDualityofLight:WavepropertiesRefractionDiffractionReflectionScatteringVfrequency,Cvelocityoflight,wavelength,vwavenumber__(2.1)-Whereh

isPlanck’sconstant,h=6.6256×10-34J.s2.Particularproper(theEnergyofaphoton)(2.2)2.2

SpectralRegions2.3a

InteractionofRadiationwithAtoms

Emission

Atom(highexcitedstate)→Atom(lowerexcitedstate)+h

Absorption

Atom(groundstate)+h→Atom(highexcitedstate)Fluorescence

Atom(groundstate)+h→Atom(highexcitedstate)

Atom(lowerexcitedstate)+hF

2.3b

InteractionofRadiationwithMoleculesE(molecule)=Ee+Ev+ErE=E2—E1=hvAbsorptionM+hv→M*FluorescenceM+hv→M*→M+hv`2.4

Instrumentation

1.TheComponentsofaSpectrometer

⑴LightSource⑵Samplecell⑶PolychromatororMonochromator⑷Detector2.Atomicspectrometrysystem3.Dispersion

⑴ByaPrism

⑵ByaGratingGratingEquation

Where::blazeangle,nr:numberofgrooves/mm,:wavelength,m:gratingorder:incidentangle,:diffractedangle,Forablazedreflectiongrating(echelette)(2.3)(2.4)lineardispersionReciprocallineardispersionDrAngledispersionofagrating(2.5)(2.6)(2.7)ResolvingPowerBlazingrangeTheminimumpositioncorrespondstoanoptimumslitwidthWhere:wisdiameterofthelens,fisthefocallength.(2.8)(2.9)(2.10)4.ATypicalMonochromatorChapter3

AtomicEmissionSpectroscopy3.1.FundamentalsofAES

3.2.Instrumentation

3.3.AnalyticalMethodsofAES3.4.ControlofAnalyticalInterferences

3.1.FundamentalsofAES

AtomicEmissionProcesses3.2.Instrumentation1.Lightsource2.Spectrometer3.Detector4.ReadoutLightSourceTypeEva.Temp.Exci.Temp.stabilityApplication.DCArchighlowpoorQualitativeAnalysisACArcmidmidgoodQualitativeAnalysisSparklowhighestgoodQuantitativeAnalysisICPhighesthighbestQuantitativeAnalysisLightSourceProgressesSpectrometer⑴MonochromaterOptical-directReadSpectrometor⑵PolychromaterOptical-directReadSpectrometor3.Detector⑴Spectrograph⑵PhotomultiplierTube⑶Segmented-arrayCharge-CoupledDetector(SCD)ICP-AESInstrumentationSystemTwo-dimensionalarrayproducedbytheechellemountFig3-16SchemeofSCDDetector3.3AnalyticalMethodsofAES1.QualitativeAnalysis

⑴StandardIronSpectraComparison ⑵IndicateElementSpectraComparison ⑶DeterminationofLineWavelength

2.QuantitativeAnalysisQuantitativeFormula⑴theoreticalFormulaofAES(3.1)(3.2)(3.3)⑵LomakinFormula

⑶InternalStandardMethods

⑷StandardCalibrationMethods

(3.4)(3.5)(3.6)3.4.AnalyticalInterferences

SpectrumInterferenceBackgroundInterferenceMatrixInterference1.SpectrumInterference2.BackgroundInterference3.MatrixInterference3.5SensitivityandDetectionLimit1.Detectionlimit

(3.7)Chapter4

AtomicAbsorptionSpectroscopy4.1.TheoreticalConcepts4.2.AtomicAbsorption Instrumentation

4.3.GraphiteFurnaceAtomic Absorption

4.4.ControlofAnalytical Interferences

4.1.TheoreticalConceptsTheAtomicAbsorptionProcessTheoreticalConceptsQuantitativeAnalysisCharacteristicConcentrationDetectionLimits

TheAtomicAbsorptionProcessFig4-3GrotriandiagramsforNaFig4-2GrotriandiagramsforK2.TheoreticalConcepts

⑴IntegralFormulaofAAS

Fig4-4TypicalShapeofAAtomicAbsorptionlineIntegralAbsorptionFormula

ByatomictheoryByLineShapeFunction(theNaturedistribute)ThePeakAbsorptionCoefficientk0is:(4.1)(4.2)(4.3)⑵PeakAbsorptionTheory

byLambert-Beer’sLaw:(4.4)(4.5)(4.6)TheAbsorbanceis:Whenva>>ve,thenkv≈k0,(4.7)(4.8)(4.9)3.QuantitativeAnalysis(4.10)4.CharacteristicConcentration

The‘‘characteristicconcentration’’(sometimescalled‘‘sensitivity’’)isaconventionfordefiningthemagnitudeoftheabsorbancesignalwhichwillbeproducedbyagivenconcentrationofanalyte.Forflameatomicabsorption,thistermisexpressedastheconcentrationofanelementinmilligramsperliter(mg/L)requiredtoproducea1%absorption(0.0044absorbance)signal.(4.11)5.DetectionLimitHavingobtainedthedata,makethecalculationasfollows:Averagethetwoblankreadingstakenimmediatelybeforeandaftereachstandardandsubtractfromthestandardreading.2.Calculatethemeanandstandarddeviationforthesetofcorrectedhigh-standardreadings.Dothesameforthesetofcorrectedlowstandardreadings.3.Iftheratioofthemeansdoesnotcorrespondtotheratiooftheconcentrationpreparedtowithinstatisticalerror,rejectthedata.4.Ifthedatapasstheratio-of-the-meanstest,calculatethe concentrationdetectionlimitasfollows:(4.12)4.2.AtomicAbsorption

Instrumentation

1.PhotometersforAASANewTypePhotometerforAAS2.linesource(HollowCathodeLamp)Fig4-13HollowCathodeLampEmissionProcessFig4-143.AtomizerforAAS(Pre-MixBurnerSystem)

Fig4-19TreeTypeBurnerHeadfordifferentTypeFlame4.ControlofAnalyticalInterferencesIonizationInterferenceMatrixInterferenceChemicalInterferenceBackgroundInterferenceIonizationInterferenceMatrixInterferenceChemicalInterferenceTheMethodOfStandardAdditionsNo.SampleAddedmlStandardAddedmlConcentr.ofstandardmg/LLastConcentriationmg/L1Vx0CsVxVL2VsVx+CsVsVL32VsVx+2CsVsVL43VsVx+3CsVsVLBackgroundInterferenceAD2=Ab,

AHCL=Aa+AbAa=AHCL-AD2(4.13)(4.14)(4.15)4.3.GraphiteFurnaceAtomicAbsorptionGraphitefurnaceatomizercomponents

TheGraphiteFurnacePowerSupplyandProgrammer

QuantitativeanalysisGFAAS

EffectofMatrixonHeightandArea1.Graphitefurnaceatomizercomponents

TheGraphiteFurnaceAtomizerAbasicgraphitefurnaceatomizeriscomprisedofthefollowingcomponents:·graphitetube·electricalcontacts·enclosedwatercooledhousing·inertpurgegascontrolsTHGAgraphitetubeFig4-27TheGraphiteFurnacePowerSupplyandProgrammer

AGraphiteFurnaceTemperatureProgramDryingPyrolysisCoolDown(optional)AtomizationCleanOutCoolDownChapter5

UltravioletandVisibleSpectrophotometry5.1.ConceptsofUV-Vis.Spectrophotometry5.2.UV-Vis.Spectrophotometer5.3.AnalyticalMethods

5.1.

ConceptsofUV-Vis.Spectrophotometry1.MolecularabsorptionandFluorescence2.Lambert-Beer’sLaw

(1)TransmittanceT:(5.1)(2)Absorbance:

(3)Molarabsorptivity

When:theunitofbisincm,Cinmol/L,molarabsorptivity

is:B:transitionprobability,:effectiveareaofmolecular(5.2)(5.3)5.2.

UV-Vis.SpectrophotometerAASpectrophotometerDoublebean

UV-Vis.Spectrophotometer5.3.

AnalyticalMethods

1.QualitativeAnalysis

2.QuantitativeAnalysis

3.DualwavelengthSpectrophotometry

4.DifferentialSpectrophotometry

5.DerivativeSpectraQualitativeAnalysis

⑴OrganicCompound

Chromophore

max(nm)

(mol-1.cm-1)TransitionTypeR3C—N—2003000n→*R3C—S—2002000n→*—N=N—34010n→*—S—S—250-3301000n→*R2C=S500,24010,9000n→*R2C=O280,19020,2000n→*,n→*—COOR205,16550,4000n→*,→*⑵InorganicCompoundIonn3d,e

max(nm)Ionn3d,e

max(nm)Sc2+0------Zn2+10------Ti(H2O)63+1492.6Cu+10------VO2+1625Cu(H2O)62+9592,794Cr(H2O)63+2407,575Ni(H2O)62+8395,650,740V(H2O)62+3557Co(H2O)62+7516,541,625Cr(H2O)62+3709Fe(H2O)63+5411,540,794Mn(H2O)63+4476Mn(H2O)62+4402,435,5323.DoublewavelengthSpectrophotometryTwo-componentanalysiswithdoublewavelengthAC,520=AC,540AB+C,520=AB,520+AC,520AB+C,540=AB,540+AC,540A=AB+C,520-AB+C,540=AB,520-AB,5404.DifferentialSpectrophotometry(5.4)(5.5)⑴whenTS,1=0,TS,2=100%⑵whenTS,1=0,TS,2<100%⑶whenTS,1>0(5.6)(5.7)(5.8)5.DerivativeSpectra5.4

MolecularFluorescence

SpectrometerChapter6

ElectrochemicalAnalysisAnodereaction:

Red===Ox+ne

-Cathodereaction:

Ox+ne

-===

Red6.1IntroductionOxidation–reductionreactionCellreactionexpression

Anodesolution,(Ox)solution,(Red)Cathode(6r-1)(6r-2)Forexample:ZnZnSO4,(xMol)CuSO4,(yMol)CuAnode:ZnZn2++2e-Cathode:Cu2++2e-Cu(6r-3)(6r-4)2.Half-cellPotentialForhalf–cellreaction:

rAred+ne-

pAOxNernstequation:ForaCell:

Ecell=Ecathode-Eanode

If,Ecell>0:PrimaryCell

Ecell<0:ElectrolyicCell(6r-5)(6-1)(6-2)3.The

TypesofElectrodesAmetalinEquilibriumwithitsions

(ClassⅠelectrodes)Ag++e-Ag(6r-6)(6-3)Ametalinequilibriumwithasaturatedsolutionofaslightlysolublesalt

(ClassⅡelectrodes)AgAgClCl-,(

=1)AgCl(s)+e-Ag+Cl–ReferenceelectrodesSaturatedcalomelelectrode(SCE)HgHg2Cl2(s)Cl-,(sat’dKCL)Hg2Cl2(s)+2e-2Hg+2Cl–(sat’dKCL)(6r-7)(6r-8)AmetalinequilibriumwithtowslightlysolublesaltswithacommonAnion

(ClassⅢelectrodes)AgAg2S,CdSAg+,Cd2+,S2-,Ag2S(s)2Ag++S2-CdS(s)Cd2++S2-(6r-9)(6r-10)4.ThedepartureofpotentialLiquid-junctionpotential

HCl(0.1M)

KCl(saltbridge,xM)KCl(0.1M)Whenx>3.6Eljp<1mVPolarization

Efact

≠ENernst

andCsurf≠Cbolk

Over-voltagerealpotentialstartareaction>equilibriumpotentialOhmdrop

Ecell

=Ecathode

-Eanode+IR

R:resistanceofsolution,I:current(6-4)6.2PotentiometryPrinciple

(6-5)(6-6)(6-7)(6-8)2.IonselectiveMembraneElectrodeStructureofISETypesFig6-1(1)TheGlassElectrodeAg︱Agcl(s)︱HCl(

inner)︱glass︱H+(unknownsolution)(6-9)Fig6-2Glasselectrode︱unknownsolution︱SCE(6-10)(6-11)(6-12)SelectivityofGlasselectrodeH+G-+M+(sol)M+G-+

H+(sol)k:selectivitycoefficient(6-13)(6-14)(6r-11)(2)TheResponseBehaviorofISENernstresponseandDetectlimit(6-15)Fig6-3SelectivityResponsetime(6-16)Fig6-4ThePrerequisiteofExperimentsIonIntensityBuffer3.QuantitativeAnalysis(6-17)(6-18)(6-19)f_activitycoefficientIfCion,T≈constant,f≈constant.pHBufferMZ++xOH-M(OH)x(z-x)+H++OH-H2OComplexreagentMZ++nL

MLnZ+

(6-20)(6r-12)(6r-13)(6r-14)(6-21)(6-22)(6-23)(6-24)(2)StandardcalibrationMethodsC0/molL-110-33.16x10-410-43.16x10-510-5lgc-3-3.500-4-4.500-5standardconcentrationseriesIf=1:E=K+slgC0Fig6-5(3)StandardAdditionMethods(6-25)(6-26)(6-27)(6-28)assume:f1=f2,

1=2,S=0.0591/n(6-29)(6-30)(6-31)6.3PolarographyIntroduction(1)ElectrolyticcellCathode: M++e-→M Hg(l)∣M+(C)︱SCE

Wkg:WorkingElectrodeRef:ReferenceElectrode(SCE)(2)Polarization

M+(Bulk)→M+(Cathode)Fig6-72.TheDroppingMercuryElectrode(DME)(1)StructureofDMEFig6-8(2)ElectrolyticcurrentandcurrentdensityFig6-93.QuantitativeAnalysis

(1)IlkovicEquationm____rateofmercuryflowD____diffusioncoefficient____Averagediffusioncurrent(6-32)(6-33)(2)ThefactorofaffectdiffusioncurrentResidualcurrentChangingcurrentMigratingcurrentMaximumphenomenonOxygeninterference4.QualitativeAnalysisHalfwavepotential(6-34)(6-35)Chapter7

GasChromatograph7.1IntroductiontoInterphaseSeparationsInterphaseSeparationsMixedSubstancesMobilePhaseStationaryPhaseSeparatedComponents2.ClassificationofChromatography

InstrumentationBythetypesofmobilephase&stationaryphaseGas-LiquidGLCGas-SolidGSCLiquid-LiquidLLCLiquid-SolidLSCBystationary’sformsColumn

PaperthinlayerByseparationmechanismabsorptionpartitionexchange3.TypicalGCSProgressesCarriergasColumnInjectorSampleDetectorChromatogram7.2PrincipleofGC1.TheInterphasePartitionofOneSubstanceC(m)C(s)(1)

PartitionCoefficientK7-1(2)

PartitionRatiokp,q:massfractioninthestationaryandmobilephasek:

PartitionRatioorCapacityfactor

:phaseratio7-27-37-42.TheoreticalPlate(1)Somecommonrelationship(2)TheoreticalPlateModel:HeightEquivalenttoaTheoreticalPlate(HETP)GasFlowrateis1plateVolumepertimeKisaconstantSamplecomeintotheplateonlybytheplateNo.07-5Binomialdistributing7-77-63.ExportCurveEquationExportCurveEquation

(Gaussdistribution)7-8(2)TheShapeofExportcurvetm(tair):unreteinedtime

tR:retentiontimeT’R:adjustedretentiontimeVm(Vair):unreteinedvolumeVR:retentionvolumeV’R:adjustedretentionvolumeh:Peakofzone:StandarddeviationY:WidthofzoneY1/2:Halfpeakwidth7-97-107-117-127-13(3)TheNumberoftheoreticalplateandHETPL:lengthofthecolumn7-147-157-157-174.VanDeemterEquationu:velocityofthecarriergasA,BandCaretheconstantsforagivensystem7-187.3SeparationofComponentsSeparationfortowcomponents(1)ResolutionR(2)SeparationFactor7-197-202.SeparationEquationofGCAssume:

Y1=Y2=Y,k1≈k2=k7-217-227-233.ThreeSeparationfactor(1)