第八章质谱法

第八章质谱法MassSpectroscopy(MS)质谱仪的一般结构真空系统进样系统离子检测器数据系统质量分析器离子源大气样品机械泵，分子涡轮泵，扩散泵，离子泵，升华泵气体：气相色谱仪(GC/MS)液体：液相色谱仪(LC/MS)固体：固体进样杆(DIP,DCI)电子倍增器，多通道板检测器光电倍增管，阵列检测器通常的离子化方法电子轰击离子化 EI化学电离离子化

CI正化学电离离子化

PCI负化学电离离子化

NCI大气压力离子化

API电喷雾离子化

ESI大气压化学电离离子化

APCIGC/MSLC/MS离子化方式分子量非极性极性EI/CIESIAPCI100,0001000离子化和碎片离子化硬无碎片有碎片APIEICI软质量分析器四极杆~80%的台式质谱仪(~3000/年)HP,PE,TMQ,Shimadzu离子阱~20%的台式质谱仪(~700/年)Varian,TMQ飞行时间(ToF)目前用户较少(50-60/年)Leco,Micromass,TMQ扇形磁场通常不是台式仪器四极质量分析器++++离子阱原理与四极杆的非常相似，离子被存储在RF和DC场中，扫描场逐出精确m/z的离子。飞行时间质量分析器++++所有离子同时启动小的离子移动速度快测量已知距离下的速度(飞行时间)扇形磁场质量分析器+++离子通过变化的磁场和电场被传输ElectronImpactIonization(EI)e-e-e-e-e-filament++++FragmentionQPElectronImpactIonization(EI)Thermalelectrons(ca.70eV)hitmoleculesandionizethem.Amplefragmentions=amplestructuralinformation FingerprintEIspectrumMethylstearateM.W.298PositiveChemicalIonization

(PCI)fromgascylinderfilamente-e-e-e-e-QPCH4

CH5+C2H5+H+-CH4[M+1]-C2H4PositiveChemicalIonization(PCI)+PCIspectrumMethylstearateM.W.298ComparisonofEIandPCIEImodePCImodeFragmentMolecularweightNegativeChemicalIonization(NCI)Negativeionformationbyelectroncapture(associativeresonancecapture)

MX+e-(~0eV)MX-.X:positiveelectronaffinitypartCH4e-MXCH4+CH3+HCH4CH4CH4e-MX-质谱图的样子?EI和CI的质谱图50100150200250300350400450500550m/z0100%51051151250100150200250300350400450500550m/z0100%241213510242EIOOOCF3CF3CH3NCI…扫描50到300amu流入质谱仪的化合物质谱图...60801001201401601802002202402602803000100%240241断裂机理1.σ断裂2.α断裂3.i断裂

4.逆Diels-Alder反应5.Mclafferty重排ConfigurationofGCMS

MassSpectrometerGasChromatographInterfaceIonsourcebox

IonSourceDesign

-Increasedionizationefficacy-Ionsourcebox

IonLens

-Highionintroductiontomassanalyzer-

Thisionlensisfunctioningforeffectiveintroductiontomassanalyzer.OptimizationforadjustmentofthisionlenswillbedonebyPCautomatically.

QuadrupoleRod

-MinimizelossesintransittotheQuadrupole-MainRodSpecificiononlycanbepassedbytheelectronicfieldintoQuadrupoleRodwhichiscontrolledbyPC.PreRodFromionsourceTodetectorrotarypumpturbomolecularpump(151L/sec)turbomolecularpump(151L/sec)rotarypumpGoodvacuumsystem-MinimizelossesintransittotheQuadrupole-

TurboMolecularPump

AircooledandoilfreeTurbomolecularPump(TMP)withlubricantimpregnatedceramicbearingsismaintenancefreeforupto25,000hours.Provideshighqualityvacuuminlessthan5mins.Iondetection

+7.5kV-+e--0.7~3.0kVAMP-7.5KV+e--0.7~3.0kVAMPe-NegativeiondetectionPositiveiondetectionGCMS-QP5050ANCIsensitivity200fgHexachlorbenzeneNCIspectrum

Masschromatogramofm/z284OFN(octafluoronaphthalene)NCIscanmodeOutstandingHighSensitivity

scanrangem/z60-310,0.5secinterval200fgS/N>30

GCMS-QP5050ANCIpesticidesdate310pg

CyanophosNCI

massspectrumphosphoruspesticides10pgComparisonbetweenEIandNCIextractfromcabbage(pesticidesadded)EIscanningmodeNCIscanningmodeComparisonbetweenEIandNCIextractfromcabbage(pesticidesadded)PrincipleofProgramedtemperaturevaporize(PTV)PTV

100CsplitMS50-250COptimizationofPTVconditionsSelectionofpackingmaterialsTenaxGC 20%OV-120%OV-1720%Dexil300

ShincarbonA

CarbopackC Traptemperature

DesorptiontemperatureTemperatureprogramVery-Large-VolumeInjectionusingPTV

EffectofTemperatureonTrapefficiencyVery-Large-VolumeInjectionusingPTV

TemperatureandSplitratioProgramVery-Large-VolumeInjectionusingPTV

2ppbeachPesticidesinn-hexane1000uL

InjectionAnalyticalConditions

GC17AVer.2

DB130mX0.25mm

50C(4)-160C-280C

20C/min5C/min

PTV

70C(1)-100C(1)-280C

30C/min250C/min

WiderangeFTD1pA280C

CarriergasHe150kPa

PrecolumnTenaxGCFeaturesofGCMSQP-5050AAnalysisofCoconutoilMSSpectrumofC48DIoptionApplicationusing

directinletprobeFront-openionchambersystem

-easymaintenance-

DualFilamentsSystem

-easymaintenance-

LCMS-QP8000Validation,ProductivityandMassDetectionWhatkindofbenefits

LC/MSuserscanget?PowerfulqualitativecapabilitySelectivequantitativecapability

M/ZM/ZM/ZWhatkindofbenefits

LC/MSuserscanget?PowerfulqualitativecapabilitySelectivequantitativecapability

A:100D:150B:100C:150m/z=150TICm/z=100ABCDHPLCMSNewShimadzuLCMS

QP-8000QP-8000isLC/MSwithAPIinterfacewhichisdesignedtobearoutineLCdetectorinournewVPseriesHPLCsystem.LCMSInterfaceCurvedDesolvationLine(CDL)DeflectorProbeSprayChamberSkimmerLensStack

RPTMP1TMP2QuadrupoleAPISprayChamberAPISprayChamberESIProbe(EasytochangetoAPCIProbe)APIProbeAPCIprobeESIProbeMobilephase,LCflowrateandNebulizerflowrateslightlyinfluencespraycondition.Youcanadjusttheprobepositiontothebestforeachcondition.TheAPCIprobecontainscoronadischargeneedle.SononeedtochangetheAPIspraychamber.EasyMaintenanceSkimmerLensstackaccessSprayChamberAccessYoucanpickitupfromuppersidewithoutanytools.Youcanremovethespraychamberfromthefrontside.Itwillbeeasytowashthispartafteranalysis.StandardSyringePumpLCMSApplicationMassSeparation

Column:STRODS-II(2.0mmI.D.x150mm)Mobilephase:65%acetonitrile-watercontaining0.1%formicacid,0.2ml/minMaltoseTIC387225195GlucoseXyloseAnalysisofmacrolideantibioticsUV210nmMDMSIMSPM-I,IISPM-IIIOMDHEMMDMSummary

质谱图和色谱图?如果我们注意这个区域...色谱图?1.251.501.752.002.252.502.753.003.25Time50100%TIC在此的细微观察是由许多点组成的...色谱图-放大2.122.142.162.182.202.222.242.262.28Time78100%TIC每个点相对于质量分析器的一个扫描(质谱图)...60801001201401601802002202402602803000100%240241质谱图

每个点有一张唯一的质谱图色谱图上的质谱图数据观察-色谱图样品运行中的每秒我们可获得一张或数张质谱图通常是把检测到的离子叠加在一起获得一个唯一的总的数值这些总的数值然后排列在一起(点对点)产生一个类似的色谱图(TIC)...每次扫描加和所有的离子得到...总离子色谱图(TIC)数据观察-色谱图我们也能显示某一张质谱图

这让我们一个化合物的信息…

…质谱图质量色谱图和TICTICMass2401.401.601.802.002.202.402.602.803.00Time0100%0100%240.271.41e5TIC4.67e5

消除背景的影响

增加信噪比

分离共流出物峰数据观察-选择离子色谱图TIC图上显示的两个接近的流出峰，但每个峰是具有不同质谱指纹的不同化合物...数据观察-选择离子色谱图11.0012.00Time0100%TIC1.57e5数据观察-选择离子色谱图100200300400500600m/z0100%254.2194.2507.3334.3399.7100200300400500600m/z0100%194.2580.4402.2226.2460.211.0012.00Time0100%TIC1.57e5分离共流出物峰10.5011.0011.5012.0012.50Time0100%0100%0100%254.235.81e4194.206.14e4TIC1.57e5质量254质量194TIC选择离子色谱图提取出离子给出更好的信噪比消除背景影响分离共流出物峰

提取出离子也能用于:

峰的跟踪

准确定量峰跟踪的实例0100%TIC2.21e61.002.003.004.005.006.00Time0.525.653.823.251.672.005.594.954.255.725.81爆炸混合物的TIC哪一个是HMX?HMX的质谱图峰跟踪406080100120140160180200220240260m/z0100%8472596911389106237131205158分子离子峰峰跟踪质量色谱图

m/z237TIC1.002.003.004.005.006.007.008.009.00Time0100%0100%2.000.525.653.823.251.672.004.954.255.81分离相邻峰的能力分子离子[M+H]+M.+[M-H]-

分辨率FWHM10%峰谷m/

M[M+H]+m/zintensity质谱分辨率复合技术GC/MS气相色谱-质谱LC/MS液相色谱-质谱MS/MS质谱-质谱MS-MS方法MS1MS2

固定 扫描

子离子

扫描

固定

母离子

扫描

扫描

中性丢失