儀器分析波譜解析

質(zhì) MassSpectrum,有機(jī)質(zhì)譜OrganicMassSpectra,質(zhì)譜 Mass質(zhì)譜 Mass質(zhì)譜質(zhì)譜計(jì)構(gòu)造、離子化的方法、質(zhì)量分析器、質(zhì)譜計(jì)簡(jiǎn)PrenciplesandApplications,JohnWiley&Sons,1996.F.W.McLafferty:InterpretationofMassSpectra,3rdedMillValley:Calif.Univ.Sci.Books.1980 :有機(jī)質(zhì)譜解 叢浦珠:質(zhì)譜學(xué)在天然有機(jī)化學(xué)中的應(yīng)用科 發(fā)展史1898W 1910JJ 物線族的質(zhì)譜,證明了20Ne,22Ne1918AJ 1919FW 制得了第一臺(tái)速度聚焦質(zhì)譜儀。提出每種

商品MS強(qiáng)度的譜,譜圖與分子結(jié)構(gòu)有關(guān)質(zhì)譜是唯一可以給出分子量,確定分子式的方法,而分子式的確定對(duì)化合物的結(jié)構(gòu)鑒定是質(zhì)譜計(jì)框

質(zhì)譜計(jì)構(gòu)10–4~10–5Pa和10–5~10–6Pa進(jìn)樣系SampleGCoutputtomassSamplealreadyingasSample+HefromGC

HeVacuumpump

Sample

ToMSSampleIntroduction:DirectInsertionProbe(DIP)DirectinsertionConceptuallyveryeasy,practicallyverySampleCeramicVacuumsealsSampleDirectinfusionofsampleinSyringepump:slowsteadyOutputfromSeparationandidentificationofVastmajorityofsolutionisMustremovesolventto Historically:extra andApplicabletoelectrosprayESI:see離子.50-.M+ M++ A+.

.8000eV加速后的通過(guò)狹縫，直線射入質(zhì)量分析器。離質(zhì)量分析檢測(cè)記錄系ElectronImpactIonization,ChemicalIonization,FieldIonizationFD,FieldDesorptionFastAtomBombardment,Matrix-AssistedLaserDesorptionIonization,ElectrosprayIonization,AtmosphericPressureChemicalIonization, 50-70eV7-15eV。ElectronImpact ::

:+:+ :

Mass化學(xué)（Chemical最強(qiáng)峰為準(zhǔn)分子離子 譜圖簡(jiǎn)不適用難揮發(fā)

氣體分 試樣分 準(zhǔn)分子離 電小分子如CH4,(CH3)2CHCH44CH+e→CH+·+2e44+ 初級(jí)離子: ,

CH2CH+·+ →CH++CH + +

→C +

+

+→C

+

CH5+,C2H5+,C3H5+M+CH5+→[MH] +M+C2H5+M+C2H5+M+C2H5+[MH]+ChemicalChemicalIonisationSofterthanEI:muchlessMethaneionisedbyOthergasesmaybeRelativelyhighpressure0.5Bimolecular5CH+behavesas“super5

+ChargeTransferin5CH+protonatessample:5 +

+MassdetectedisNotaradicalcation:c.f.EI&CI:applicabletolow i.elessthan y800場(chǎng)致FieldFieldDesorption++電壓：7-10kV；d<1++++++++++++++++++++++碎片離++不適合化合物結(jié)構(gòu)鑒定場(chǎng)解吸樣品不需汽化,預(yù)先附在處理好的場(chǎng)離子發(fā)射從發(fā)射體上解吸下來(lái),并擴(kuò)散至高場(chǎng)強(qiáng)的場(chǎng)發(fā)射區(qū),快原子轟擊使之具有高的動(dòng)能，在原子槍(atomgun)內(nèi)進(jìn)行電例如：3m/z154(MH),136（MH–H2O）,289(MMH–H2O)的峰?；|(zhì)輔助激光解析電離IonisationMethods:MatrixAssistedLaserDesorptionSolidmatrix:e.g.dihydroxybenzoicMatrixabsorbsenergyatoflaserCausesvapourisationofmatrix Protontransfer yte(orLi,Na,DetectionbymassApplicabletoMWupto12,000DThermallylabile PolymersandbiomoleculesIonisationMethods:SchematicofAMALDIChamberSolid

電噴霧電離 電噴霧電離Charged-+ -+

yteSolventIon -

Salts/Ion++

++-----

+++

++

- +-+-+-+--

+其他試樣電噴霧電離電噴霧電離電噴霧電選相鄰峰，電荷nn+1m1=(Mr+n)/2m2=(Mr+n+1)/質(zhì)量分析器 Separateionsaccordingtom/zFivebasictypes Magneticsector Ion Timeof FactorsFactorstoUppermassHighestm/zthatcanbeMaybeoffsetbymultipleDistinctsignalsforsimilarm/zRatioofionsreachingdetector:ionsResolutionResolution(ResolvingAbilitytoresolvetwosignalsofsimilarResolvedifvalleyisHigherresolution:greatere.g.Accuracy

m/zm/zHighResolutionMassSpectrometryDetermineelementalcompositionofanVitaltoconfirm HighResolutionMassHRMSoraccuratemassDetermineselementalConsidertwo

nominalmass:nominalmass:UsingC=12,H=1,N=14andCanwedifferentiatethesetwoNeedtocalculatethemonoisotopic ExactsofbundtC=12.0000,H=1.0078,N=14.0031,1)[C24H19N]+:accuratemass:321.15132)[C21H23NS]+:accuratemass321.1546R=M/M=321/(321.1546-=MassspectrometerwithR100,000candistinguishbetweenthesetwoions質(zhì)量分析

12

1mv22IFIIFB

mv

Bzv。mvR

Bz 1mv2

zV

mBR 2V當(dāng)儀器的狹縫固定()（則離子按m/z相同m/z的離子，速度相同，色散角不同，經(jīng)磁場(chǎng)偏后，會(huì)重新聚在一點(diǎn)上。即靜磁場(chǎng)具有方向聚焦，稱之單聚焦磁R磁RB方向聚焦分辨率靜電分析分析雙聚焦質(zhì)靜電分析器中,受到外斥內(nèi)吸的電場(chǎng)力(zE)的作用, 1mv22

RE雙聚焦質(zhì)譜儀體積大色譜質(zhì)譜聯(lián)用儀器的發(fā)展及儀器小型化（臺(tái)式體積小的質(zhì)量分析器：

四極質(zhì)量–四極ElectronSample

Ion 合于GC-MSLC-MS四極質(zhì)量分析器–四極質(zhì)離子源出來(lái)的離子到達(dá)四極質(zhì) 現(xiàn)象，掃描速度快，適合于GC-MS,LC-MS。分辯率不高。 QuadrupoleMass RelativelycheapandLow(unit)RUppermasslimitofm/zCanbeoffsetbyuseofESI(multipleSimpletooperateandSimpleinterfacingwithinletGC,DIP,Workhorsesofmass ysers:Quadrupole:GeneratingTheMassSpectrumDCandRFvoltagescauseionStableoscillation:ionspassthroughUnstableoscillation:discharged(notVaryDCandRFtodetecteachm/zinGeneratesmassUsedforlowMWsimpleHRMSnotpossible:R2-Unit(Dalton)resolution離子漂移管-飛行時(shí)間質(zhì)譜（TimeofFlighMS,

1mv22

v(2zVmt可得到質(zhì)譜圖，t為或sTimeofFlightDevelopedinPopularisedinAdvantage:nouppermassDisadvantage:poorTimebetweeniongeneration& y10-7 SchematicDiagramofaTOFIonsacceleratedbyelectricIon TOF:Determiningm/zAssumeallionshavesameKEKineticEnergy=Electrostatic?mv2=zVv2=Timetakentoreachdetectortd=distancetravelled,v=t2=d2/v2=m/z=2Vt2 TimeofFlightReflectronImprovesresolutionofR5-20,000(highenoughformostIonsgeneratedandacceleratedasIn regiontheionsareSlower(lessenergetic)ionspenetratereflectingless:quickturnFaster(moreenergetic)ionspenetratereflectingfieldmore:slowturnaroundIonsofsamem/z:detectedatsame SchematicofaTOFReflectronltnfilter:improved 變換質(zhì)FourierTransform–MassSpectrometer,FT- 譜計(jì)，是受FT-NMR的啟迪。利用不同m/z的離子，在磁使其頻率等于某一m/z離子的回旋頻率，則離子就會(huì)吸收 vr ysers:FourierTransformIonCyclotronResonance:FTICRHighR(>100,000):unlimitedmassApplicableto NotGC-MSasverylowpressuresareIonorbitsinacircularmagneticIfmv=zBr:ionistrappedincircularFrequencyofthisoscillation=c=zB/mm/z=cisameasureofVeryhighcost:€ IonTrap Typeofquadrupole Similarresolutionof2-IonistrappedinanelectromagneticInastableFieldstrengthUnstableoscillation:ionejectedandVaryfieldstrength:scanforallGeneratemassLC-MS(LC-MS(離子阱)IonIonSampleDIP,GC,IonisEI,CI,FAB,ESI,IonisMagneticsector,TOF,iontrap,Ionmustnowbe2TypesofIonDetection:ElectronMultiplierIoncollideswithCausesemissionofRepeated10-20CurrentgainCurrentisthenSensitive:singleionLifetimeof1-2IonDetection:ScintillationCounterIonstrikesElectronsthenhitphosphorusLightsignalamplifiedbyPhotomultiplierSensitive:singleionLifetimeof y5質(zhì)譜計(jì)的主要 分辨率（R）：分辨率是質(zhì)譜計(jì)分開相鄰兩離子質(zhì)量的R=m/m為質(zhì)譜計(jì)可分辨的相鄰兩峰的質(zhì)量m為可分辨的相鄰兩峰的平均質(zhì)分辨率（R）是兩峰間的峰谷為峰高的10%時(shí)的測(cè)定 質(zhì)譜術(shù) 100 質(zhì)荷比:mzz1,zm的計(jì)算：組成離子的各元素同位素的質(zhì)子和中子精確質(zhì)量:精確質(zhì)量的計(jì)算基于天然豐度最大的同位素1H1.00782512C12.00000014N14.00307416O95質(zhì)譜強(qiáng)度或相對(duì)豐度。乙醇的質(zhì)譜圖如下：分子離子:M+ M-e→M+z=1m/z奇電子離子OE+·M+·A+·C+·偶電子離子EE+B+D 如z=2的離子，存在于穩(wěn)定的結(jié)構(gòu)中準(zhǔn)分子離子 [MH]+,[M-亞穩(wěn) <106s的 106-105s的離子，從離子源出口到達(dá)檢測(cè)器之 是因?yàn)閙1+裂解時(shí)，部分內(nèi)能轉(zhuǎn)化為動(dòng)能。在質(zhì)譜解析中，m*可提供前體離子和子離子之間分子離子或準(zhǔn)分子離子123H2,OΔm4-14,21-24,37-38判斷其是否符合N偶數(shù)。含奇數(shù)N的有機(jī)分子,其分子離子峰的m/z為奇數(shù)。◎使用CIM+H,MH,M+C2H5◎使用FABM+H,MH,M+Na,◎M+H,M+2H,M+3H合理碎片丟b最大離子為122，相鄰的120可以考慮為c最大離子84，最近離子69，也合理，但分子離子峰的相對(duì)強(qiáng)度(RI采用>>分子分子離子往改用其它離解方式 如:CI,FAB一些同位素AtomicWeightsandapproximatenaturalabundanceofsome Atomic Natural 利用低分辨質(zhì)譜同位素峰簇及其相對(duì)對(duì)于CH,N,ORI(M+1)/RI(M)×100=1.1x+2H0.016,17O0.04RI(M+2)/RI(M)×100=(1.1x）2/200+含硫的樣品32S33S34S100:0.8RI(M+1)/RI(M)×100=1.1x+0.37y+RI(M+2)/RI(M)×100=（1.1x）2/200+0.2w含Si28Si29Si30Si1005.1含重同位素（Cl,Br）35Cl:37Cl=100:32.5≈3:79Br:81Br=100:98≈1:◎分子中含1M:M+2≈3:◎分子中含2M:M+2:M+4≈9:6◎分子中含1M:M+2≈1:◎分子中含2M:M+2:M+4≈1:2◎分子中含1Cl和(a+b)(c+d),M:M+2:M+4≈3:4:例m/z154154-139=15,m/z 156 H數(shù)目不設(shè)：分子離子峰：7272–58=14？7373–5815(1.9/37)100=1.1x+0.37z,z=1,x=5,y=73–14–60=–1?z=1,x=4y=73–14–48=11分子式C4H11N,164:166=1:1,164-85=79164166≈11分子中含有不含氮或含偶數(shù) 49(100), 3.2(6.5), C6H13or C6H13BrDBE=0C5H9BrODBE=1例某質(zhì)譜圖高RI 4C CHN ※精確質(zhì)量的尾數(shù)=0.007825y0.003074z-BeynonandLederbey有機(jī)質(zhì)譜中的裂解M

50-

+.+MM-.+小于A+. +MB +A+. B M+·→ C D+亞穩(wěn)離同位素標(biāo)mm*m2mm1–Δm→ 前體離子（母離子），Δm=15(CH3）,18(H2O),28(CH2CH2,CO)2H標(biāo)記，其質(zhì)荷比大于未標(biāo)記的分子離子或例如:醇失水，MS證明是1,4氯代烴脫HCl1,3-失HClMcLaferty自由基 電子配對(duì)傾

+

YR'分子中n電子比π電子易丟失，π電子比σ電子易丟失偶電子規(guī)律 →EE+ OE+·→OE+· OE+·→ 如何識(shí)別質(zhì)譜圖中的的不含氮的化合物,m/z為偶數(shù)的離子是奇電子離子在質(zhì)譜圖中,奇電子離子并不多見,但重要有機(jī)質(zhì)譜的碎裂機(jī)EE+離子系列:偶電子碎片離子系列(even烯烴

飽和脂肪胺醛類：44，58，72，86，100苯：39，51，65，77，91，105腈類：40，54，68，82OE+離子：指奇電子離子（odd它一般簡(jiǎn)單斷裂的規(guī)含雜原子化合發(fā)生α碳碳不飽和鍵相鄰的C—C芳環(huán)相鄰的C—C鍵易斷裂。（環(huán)的情況也類似碳鏈分支處易發(fā)生斷飽和環(huán)易在環(huán)與側(cè)鏈當(dāng)分支處由幾種斷裂可能團(tuán)斷裂產(chǎn)生電中性小分子的開裂

C C

R 1CCR 1CC=OαCO++O11）α碎裂:指游離 的,由游離基重新組新鍵而在α位導(dǎo)致碎裂過(guò)酮O醚 R1 R2O

R1 O=CH2 R2 ++OH+OHαRHN=CH ++OH+OHαRHN=CH R+RHN+R CHH=+R2+R醇胺α++α++R2+R1R1R2 ++R1R2O+O O+O烯酯RCO+ +R+CORRCO+ +R+CORRC+i(CH3++CH2=C+OOO +CO酮氯代物酯σ過(guò)程這是當(dāng)σ鍵形成陽(yáng)離子自由基 e

++α+ +

+E

++HHH+r+HHH+r+++XXYY r +Q+ZZHO+Hhydrogen）Mclafferty麥?zhǔn)现嘏臦，X，Y，Z一般為碳、氧、烯H+H+OH+H+rO +O酯O+rO+r+O +OHH+HO OH+HHH+H+HOHO OH+HHH+H+HOHHN+N+HCH2rH,+CH2+ ++ +HOOH++ OO+HHO+OH這類重排可小結(jié)為++rHOE+OE+rH+++NN(N為中性分子rd過(guò)程：RRRR++ +R偶電子離子氫的

CHNHCH

HC

H

m/z= 22

RCH

m/z=

RCH

2 2

m/z= Y

XH2O,H2S. +

HOR,HSR,O +HO

+

各類有機(jī)化合物烴類化烴類化合物的裂 CH2> CH2>CR3 m/z=91,

m/z=C6H5CH2(CH2)nCH3

m/z43或57m/z91烴類化合物烷烴-直鏈烷烴 峰弱，可見m/zM-

(主)，m/z43577199,11·等;Δm14m/z42,56,70,84等。m/z41556983

4357(CHC基峰或強(qiáng)峰n-十六烷的質(zhì)譜圖烷烴烷烴 M+· M-15(·CH3),帶側(cè)鏈CH3 M-R·R離子峰RI烷烴以環(huán)己 較強(qiáng),因裂解丟失基團(tuán)需斷m/z41。55,69峰。自由 ，經(jīng)過(guò)四，六元環(huán)過(guò)渡態(tài)氫轉(zhuǎn)移，裂解如+m/z

- -

m/z+CH

- - + m/z m/z甲基環(huán)己烷 峰較弱，但比相應(yīng)的烷烴強(qiáng)。m/zα斷裂（末端烯），m/z41CH2=CH-CH2基峰或強(qiáng)峰γm/z42CH2=CH-CH3+·,基峰或強(qiáng)CnH2n-CnH2n

m/z41556983,m/z4357718599113·Δm= m/z42567084等42+14n注意：重排時(shí)，雙鍵可能發(fā)生移動(dòng)，其位置難十二烯 環(huán)烯RDA環(huán)烯RDA 芳烷基苯M+·強(qiáng)或中等強(qiáng)度α斷裂，產(chǎn)生m/z91的基峰或強(qiáng)峰γ-H的重排，產(chǎn)生m/z92的奇電子離子峰，進(jìn)一步裂解，產(chǎn)生m/z785266，40的峰。 2 m/z m/zHHm/z

m/z

m/z

+

m/z

m/zm/z m/z例如,正己基苯的MS如下醇?M+·弱或CnH2n+1O的含氧碎片, m/z31,45,5 的α-裂解）。M-18,M-18-伴有CnH2n m/z43,57,71,99,1等

iR+）m/z42567084等,分子失水后類似于烯烴的裂解C m/z41556983·αRCH2α

m/z H

C

m/zM-18-

+ + m/z m/zCHO

C m/z m/z m/zm/z

H m/z

m/z

m/zm/z m/z醚M+·弱,[M-CnH2n+1O的含氧碎31455等.α斷裂,β-H轉(zhuǎn)移CnH2n m/z43,57,71,99,11等。(i異裂R+C-Oσ鍵斷正電荷往往帶在R基上低質(zhì)荷比區(qū)伴有CnH2n,CnH2n-1峰與醇類的區(qū)別無(wú)失水峰M+·M+·較強(qiáng)，類似于脂肪醚的裂解方式β-H轉(zhuǎn)γ-H重H+

O+HO+H C

m/z

m/z m/z取取代基的位置對(duì)其質(zhì)譜有較大的影+ CH

CH

Cm/ 138(100 m/ 123OCH

OH2 m/ 95

m/ 7

硫醇、硫 M+·的相對(duì)強(qiáng)度M-33(-HS),M-34(-H2S),33HS+,34H2S+47,61,75,8·伴有CnH2n m/z11· 和H2n-1(長(zhǎng)鏈烷基硫醇尤為明顯例如n- _H C

硫M+·的相對(duì)強(qiáng)度較相應(yīng)的C-Sσ鍵斷裂,正電荷往往帶在含S碎αCnH2n+1S的含硫片,47,61,75,8·四元(β-H),五元,六元(γ-H)過(guò)渡態(tài)的重

H

+

S

m/z + m/z+ 或

- m/z或 胺類化合物的M+·的RI較較仲胺,叔胺或大分子伯胺M+·峰往往不出含奇數(shù)個(gè)NM+·的m/z奇數(shù)的能力大于O,S)CnH2n+2NN特征碎片峰,m/z304458,·等3014n峰β-Hβ-鍵斷裂,其m/z44(or44+14n58(or58+14n+

m/z+H

H NHR'-2 NHR'2

2m/z44+14nR'

m/z-H

RCH2

R'>2C m/z m/z三乙胺的質(zhì)譜

m/z m/z +m/z

+m/z脂肪族鹵代烴M+·的RI由F→I依次增αR(RFRClC-Xσ-鍵斷裂

(RBr,

(CH2)n=

+(CH2)X基存在的特RFM-19,M-20(-F,-RCl位素峰M-35M-36ClC3H3Cl3的質(zhì)譜

144 BrRIM–127,m/z127的I+F

F子系列峰，如m/z29、43、57……等O

+/z環(huán)己酮的裂解可產(chǎn)生、-CHO離子，OO OHHHH H離子具有γ－H的醛、酮可發(fā)生麥?zhǔn)现嘏欧碒OC CH

CHRCH

O CH

CHRCHAH:A＝R羧1．脂肪羧酸的分子離子峰很弱，m/z羧是丁酸以上α－碳原子上沒有 CHO CH

CHR CH2

OH HO CH2

CHRCH2OHCHO CH2 酯酯+ O

或 M－15、M－29、M－43 、、、等M－59、M－73O

m/z31、45、59(M-43、M－47等(M-31、M－45等mz43、(M-31、M－45等OC

CHCH2CH

2

OH

CHR

R'=CH3 時(shí)mz=74RC2H5時(shí)mz=88

R'=

O γ -H O

O

R=CH3 時(shí),RC2H5

酰酰OCNH2

+CHA+

CHRCH2

NH2

OHCCHA

CHRCH2NH2

OHCHA

A=H A=CH3:A=C2H5

m/z=59m/z=73m/z=87O2 NHO2

CNHORCRNH

ONHC5H12OMW=IUPACName:2-pentanolMSFragments:Thespectrumshowsasmallmolecularionandasmallpeakresultingfromlossofahydrogenatomfromthealcohol.Lossofamethylgroupgivesthem-15peakandlossofhydroxyradicalgivesthesecondarycarbocationatm-17.Thebasepeak,notsurprisingly,isformedbyexpulsionofthealkylchaintogivethesimpleoxoniumionatm/e=45.C7H12BrMW=IUPACName:bromomethylbenzene(benzylMSThespectrumshowstwosmallpeaksofequalintensityinthemolecularionregion,stronglysuggestingthatthemoleculecontainsbromine(equalconcentrationsofthe79Brand81Brisotopes).Thebasepeakrepresentslossofthisbrominetogivethepeakatm/e=91,whichishighlysuggestiveofabenzylfragment,whichrearrangestoformthetropyliumcationysis:C9H10OMW=IUPACName:3-pentanone(diethylketone)MSFragments:Thespectrumshowsamoderatemolecularionpeak,andapeakatm-15,stronglysuggestingthepresenceofalabilemethylgroup.Thebasepeakoccursatm/e=91,whichishighlysuggestiveofabe