岛津 GCMS 培训教材

GCMS

*Shimadzu International Trading (Shanghai) Co. Limited

GCMS : /GC:Gas chromatographMS: Mass spectrometer


GC


MS

GC


99.999%10%



/SPLWBIOCIPTV/GCMSGC


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? 1mL/min 46mL/min-->46:1

46mL/min


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e.gSPL-2010(Split)25mm10-15mm(10mg)34mm_


ppm30mL/min 50:1100:1


I0.25mmI.D.x 30m , df=0.25um1mL/min50mL/min47mL/min46mL/min-10

1min3mL/min1min


II0.25mmI.D.x30m , df=0.25um1mL/min4mL/min1mL/minCarrier GasP

0mL/minSplit 50mL/min47mL/min46mL/min1min3mL/min


1min1min


112


-10


Rtx-5 30m0.25mm0.25um1.0L5ug/mL 150C to 275C @ 4C/min.Rtx-5 30m0.25mm0.25um1.0L5ug/mL 40C to 150C@ 25C/min. 275C @ 4C/min.


0.25mmI.D.x 30m , df=0.25um1mL/min9mL/min-10

6mL/min0mL/min3mL/min1min1min1mL/min6mL/min100Kpa250Kpa 1min100Kpa1mL/min


ppm 1020


WBI


1.Column Sleeve/Guide (OCI-mode)2. Glass Insert)(PTV-mode)OCI/PTV


-200300


-280200


34040


-2uL)


Wall Coated Open Tubular



WCOT :Polysiloxanes, siliconesPolyethylene glycols, PEG


siloxanebackbone


ms or low bleed version


100 C270 C300 C300 C for 12 minBleed


WAX or FFAP e.g. Rtx-WAX, Stabilwax-DADB-FFAP


RestekJ&WSGEAlltechMachereyNagel100% dimethyl polysiloxaneRtx-1Rtx-1msDB-1DB-1MSBP1AT-1AT-1MSOptima 195% dimethyl/5% diphenyl polysiloxaneRtx-5Rtx-5msRxi-5msDB-5DB-5MSBP5BPX5AT-5AT-5MSSE-54Optima 5

65% dimethyl/ 35% diphenyl polysiloxane Rtx-35Rtx-35msDB-35DB-35MSBPX35BPX608AT-35-50% dimethyl/ 50% diphenyl polysiloxaneRxi-17Rtx-50DB-17DB-608BPX50AT-50Optima 176% cyanopropylphenyl/94% dimethyl polysiloxaneRtx-1301Rtx-624DB-1301DB-624BP624AT-1301AT-624Optima 1301Optima 62414% cyanopropylphenyl/86% dimethyl polysiloxaneRtx-1701DB-1701BP10AT-1701Optima 1701trifluoropropylmethyl polysiloxaneRtx-200DB-200DB-210AT-210Optima 21050% cyanopropylmethyl/50% phenylmethyl polysiloxaneRtx-225DB-225BP225AT-225Optima 225polyethylene glycol (PEG)Rtx-WAXDB-WaxBP20AT-WAXCarbonWAXOptima WAXpolyethylene glycol 2-nitroterephthalateStabiwax-DADB-FFAPBP21AT-1000Optima FFAP


(--> .(e.g.Rtx-1)(e.g. StabilWAX . - (e.g.Rtx-1) - (e.g. StabilWAX


-->[: : -->[: : -->[ : ] -->[ : : ]


MS 0.25mm 1-2ml/min 0.32mm 2-4ml/min 0.53mm 10-15ml/min GCMS-QP2010 Plus:15mL/min(EI


) ()( ) () GC-2010/2014 . ()


()20304050604090140190240290340390 cm/sec0.25mmID x 30m , df=0.25mHe:150kPa,2.32mL/min,45.1cm/secHETPuoptHminu cm/s

MS


InterfaceInterface:GC to MS 85%Vespel+15%


- - ionair, water etc.



() Turbo molecular pump


GCMS-QP2010 Plus


Ionization ()EI (Electron Impact)CI (Chemical IonizationPCI)NCI (Negative Chemical Ionization)


e-e-e-e-e-Sample from GCfilament++++Fragment ionQPEI()MeM+2e


EI


70eVA-B-C-D e ()


EI m.w.78


from gas cylinderfilamentQPCH4 CH5+C2H5+Sample from GCH+-CH4[M+1]-C2H4CI ()


Reagent gas ( 10Pa ) ( ) pseudo-molecular ions,M+1CI


EICIMethylstearate M.W. 298EICI


NCI ()Reagent gas ( 1Pa ) ( ) ()-)


NCI M.W. 284


GCMS




m/zVmmass numberz charge ( =1 in GCMS)k constant V :voltage applied to QP




0.5 secSCAN mode


TIC: Total Ion Chromatogram MS: Mass Spectrum MC: Mass Chromatogram MIC:Mixed Ion Chromatogram MCMSTIC&MC



SIM(Selected Ion Monitoring) mode(SIMTimeVm/z0.2secV85V97SIM


Scan &SIM Modem/zRetention timeTIC : Scan Mode7254152SIM


SIM Mode Scan


Typical ContaminantsMass (M/Z)Compound ClassificationPotential Source--------------------------------------------------------------------------------------------------------------------------------18, 28, 32, 40, 44AirH2O, N2, O2, Ar, CO231SolventMeOH43, 58SolventAcetone77Benzene, Xylene85Freons91, 92Toluene105, 106Xylene22, 73, 147, 207, 281, 295, 355, 429DimethylpolysiloxaneSeptum/column41, 45, 55, 57, 71, 85, 99HydrocarbonFingerprint/pump oil149PhthalatesPlasticizers


MStuning


PFTBA relative m/z intensity 69 100.0131 26.0219 32.0414 2.0502 2.0614 0.4


DI(GC).

Sheet1

500

5,10,20,40,80,MAX/


GC . . 500 5 . DI-EIDI-CIDI-NCI.


12134() GCMSsolution


1608GC DI


DIDI-EIDI-CI


100TIC500DBDEPSDI-MS


GC: MS:


WIDTH SLOPE DRIFT T.DBLGCMS


(WH/2+IS:100ppm 1uL A11.20.70.58 1uL A:100ppm :100ppm A120010001.2ISIS7001000 0.7 A :100ppmX:0.58=58ppm



GCMSI 10.6-0.7Mpa 2 3 4 1GCMSreal time analysis 2systemconfiguration 1vacuumcontrol 2 Auto startup 1Date Acquisition GCMS2 AcquisitionDowmload Initial Parameter


1Tuning2PeakmonitorviewMonitorWater,air 3StartAutoTuning

1DataAcquisition Sample login 2StandbyGCMSReadyStart 1GCMS Postrun Analysis 2Data explorer 3 1 Toolsdaily shutdown 2 Vacuum controlAuto shutdownGCMSII

GCMS


GC


?- - - ?- ( > 99.999% )-


100


Shutdown




GC-2010



1N 78


DMCS() (1) ,(2) 5% DMCS12 (4) (5) 2-3 ,1(6)



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1 2 99.999% 3


1 12 23050cm


GC-2010


MS PFTBAMS


MS(1) GCMSsolutionTuning (2) Peak Monitor View(3) (4) 18282818(5) 3243501KV(6) (7) 43


1 2 / 5103 4

3000




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11) Detail2)3)


2


*At first , we are broadly viewing GCMS.

GCMS is the hyphenated instrument combining GC, Gas chromatograph, and MS, Mass spectrometer.

GC is the instrument for separating sample components.The samples applying for GC are the ones to be vaporized easily.The sample with mixed components is injected to injector.The injector is heated , so the sample is vaporized.The vaporized sample enters into column with carrier gas,and are separated in the column and get to the detector .

From the view of GC, the MS is one of GC detectors.

Excuse me, your printing has a error . add spectrometer after mass

Now then the story enters to MS Quadrupole type of MS is composed of, mainly , the four sections, (1)ion source box (2) lens system (3) rod system and (4) detector(1) In ion source box, ions are generated(2) lens system leads effectively ions to entrance of Rod(3) rod system separates ions according to mass(4) ions are detected by detector

I add some comments on the detector.In QP2010, we use electron multiplier with conversion dynode as ion detector.The conversion dynode have been introduced at Qp5050A in Shimadzu.The conversion dynode is a kind of electrode and make it possible to increase sensitivity at high mass region and detect negative ions.

We call the introduction part from GC to MS interface.We insert the column into interface and seal with nut and ferrule for vacuum sealing.Taking a look at MS from another side, MS is the vacuum instrument.

In low vacuum , There are many neutral particles, such as air and water molecules. Ions collide with these residual neutral particles and ions immediately disappear. On the other hand , in high vacuum , ions can keep flying for a long distanceWe call the average flying distance of molecules without collision with other molecules Mean free pathThat is , ions have longer mean free path in high vacuum than in low vacuum.

High vacuum is required for ions having long life time.Ions can reach to detector in only high vacuum.

Evacuation system is composed of vacuum chamber containing MS units, main pump evacuating the chamber ,and the fore pump. As fore pump, the rotary pump is usually used.

The evacuating system removes neutral particle from MS and provide an adequate mean free path for ions

The vacuum inside chamber is usually 10 -3 to 10-4 Pa. for MS Under this vacuum, ions can fly almost 5 to 50 meter. This distance is enough for ions to reach detectors from ion source.

About main pump , Turbo molecular pump and oil diffusion pump is usually used.

In turbo molecular pump, rotating blades with high speed is used for evacuating. In oil diffusion pump the heated oil is used.

Generally speaking, turbo molecular pump is more expensive but shows more excellent performance.

Especially, diffusion pump may give contamination by oil . This is serious when electric power failure. There are two types of pumping system.One is simply single pumping system, whole chamber is evacuated by a single main pump.

The other is differential pumping system In this system, the room containing the rod and the detector is isolated from ion source room with a wall having a small hole for ion passage.The two rooms are respectively evacuated by two main pumps. Even if carrier gas flows into MS, gas entering into the rod room is very small. So the room of rod and detector is kept in high vacuum for high flow rate carrier gas. At EI ionization , a molecule is broken up at weak bonds by electron energy.

Consider a molecules composed of A,B,C,D. If there is no fragmentation, the ion ABCD+ is generated. We call such an ion molecular ion

If the bond connecting C &D is cut,ion ABC+ or D+ is generated.Such broken ions are called fragment ions

A compound shows a specific mass spectrum pattern.We use this spectrum as tool for identification.Some libraries on mass spectrom are published and we can get them.We can easily identify the measured spectrum by library search routine program.

Note that the spectra on libraries are measured with electrons of 70 eV energy.

We call most intense peak in the mass spectrum base peak.

This is the example of EI spectra.The upper is for Benzene.The base peak is the molecular ion 78The lower is for AcetoneThe base peak is the fragment ion 43The next is the chemical ionization method

In CI, reagent gas is required for ionization.

Since CI can be occurred at more than about 10Pa of ion source pressure, the ion source is closed type.The feature of CI is the ionization with less fragmentation, we call such an ionization soft ionization.

In the CI pseudo -molecular ions tend to be generated.The pseudo-molecular ion is the ion such that a proton ion H+ is added to sample molecule. So the mass number of pseudo-molecular ion is the mass number of sample molecule +1

Thus CI is effective for determination of molecular weight.

These are the spectra of Methylstearate for EI and CIThe molecular weight of this compound is 298.

EI spectrum shows existence of many fragment ions.On the other hand , CI spectrum clearly shows pseudo-molecular ions at m/z 299. The next is NCI

In EI and CI , positive ions are measured. But In NCI case ,negative ion is measured

Reagent gas isalso required in NCI.

In NCI case, the ionization can be occur at more than about 1PaSo the tightness of NCI ion source box lies midway between EI and CI.

NCI is also soft ionization .NCI is occurred through electron capture reaction because ion is generated by electron attachment to sample molecules

NCI is highly sensitive for molecules with high electron affinity, such as Halogenated compounds.

In QP type mass spectrometer, ions are separated in quadrupole rods.

Quadrupole rods are consists of four rods and the voltage is applied to each rod.

If the voltage V1 is applied to rod, ions with m1 can pass through but the ions with other mass go off course.

So we can pass the ions with desired mass by applying appropriate voltage to rods

If we varies the voltage continuously, the passing mass varies accordingly and we can get mass spectrum.

MS has the two data acquisition mode, one is scan mode and the other is SIM mode.

As explained before, When V is continuously changed, the ions enter the detector in sequence of mass.We call the changing range Scan rangeIn this example , the scan range is from 35 amu to 350 amu .We can get the mass spectrum from 35 amu to 350 amu from this measurement.

The spectrum is usually measured every 0.5 to 1.0 seconds.

We can deduce some chromatogram from the scan data.

One is mass chromatogramThis chromatogram is drawn using the necessary mass numbers data out of scan data.

Peaks are resolved into single components or a combination of components.

From mass chromatogram, (1) The detected ions are resolved as noise or signal(2)Target components are elucidated from multiple peaks

Quantitation is easily performed.

We call the summation of mass chromatogram over whole mass TIC total ion chromatogram.

TIC approximately corresponds to chromatogram of GC. Another acquisition mode is SIM (selected ion monitoring).

In this mode, the voltage is not continuously varied, but is set at only desired mass numbers.

This mode is used primarily in quantitative analysis.

We can get higher sensitivity than mass chromatogram of scan mode because of longer period measurement for remarkable masses

Selection of the mass of target compound is very important with SIM method.High sensitivity analysis is possible depending on the ion selected.

S/N)Ive been talking about GCMS, but theres no limit for this theme.But I think I gave you essentials for GCMS, So Id like to end my presentation.

岛津 GCMS 培训教材

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