Gas Chromatography-Mass Spectrometry (GC-MS) yog ib txoj kev tshuaj xyuas muaj zog uas muab cov peev xwm sib cais ntawm cov roj chromatography nrog lub zog txheeb xyuas ntawm mass spectrometry. Txoj kev no yog siv dav rau kev tshuaj xyuas zoo hauv ntau qhov chaw, suav nrog kev saib xyuas ib puag ncig, kev nyab xeeb zaub mov, thiab kev tshawb fawb txog kev ua txhaum cai. Tsab xov xwm no yuav tham txog cov ntsiab cai ntawm kev nrhiav cov ntaub ntawv mass spectrometry, cov ntsuas khaws cia, thiab cov txheej txheem siab heev hauv kev tshuaj xyuas GC-MS.
Tshooj 1: Kev Tshawb Nrhiav Cov Ntaub Ntawv Mass Spectrometry
Tam sim no, feem ntau ntawm Electron Ionization (EI) mass spectrometry databases feem ntau yog tsim los ntawm kev siv quadrupole mass spectrometers. Lwm hom mass spectrometers yuav ua rau muaj kev sib txawv ntawm pawg, uas tuaj yeem ua rau muaj qhov tsis raug hauv kev txheeb xyuas cov tshuaj sib xyaw. Hauv kev tshuaj xyuas GC-MS, nws yog ib qho tseem ceeb kom rho tawm cov suab nrov tom qab los txhim kho kev ntseeg siab ntawm cov txiaj ntsig. Cov kauj ruam no ua kom ntseeg tau tias cov cim tau txais yog sawv cev ntawm cov analytes ntawm kev txaus siab es tsis yog cov khoom cuav lossis cov kuab paug.
Thaum xaiv cov mass spectra rau kev txheeb xyuas, ib tug yuav tsum ceev faj txog cov teeb meem tshuaj ionization uas yuav tshwm sim. Cov txheej txheem ionization sib txawv tuaj yeem ua rau muaj ntau yam qauv sib txawv, ua rau cov txheej txheem txheeb xyuas nyuaj. Ntawm ntau yam txheej txheem mass spectrometry, quadrupole mass spectrometry yog paub txog nws qhov tseeb tshaj plaws, feem ntau kwv yees li ntawm 25%. Piv txwv li, ion trap mass spectrometry ua raws li qhov tseeb qis dua me ntsis, thaum Time-of-Flight (TOF) mass spectrometry feem ntau muaj cov nqi txheeb xyuas tsis zoo. Qhov tsis sib xws no qhia txog qhov tseem ceeb ntawm kev xaiv cov txheej txheem mass spectrometry tsim nyog raws li cov kev xav tau tshwj xeeb.
Tshooj 2: Cov Ntsiab Cai thiab Cov Txheej Txheem ntawm Kev Khaws Cia Cov Ntawv Qhia Txog Kev Tshawb Fawb Zoo
Tus ntsuas kev khaws cia (RI) yog ib qho tseem ceeb hauv GC-MS uas pab txhawb kev txheeb xyuas cov khoom sib xyaw. Hauv qab no yog GC ntawm Diallyl trisulfide thiab 4-methylthiazole.
Cov Ntsuas Kev Khaws Cia nyob rau hauv Isothermal Cov Xwm Txheej:
Hauv kev teeb tsa roj chromatography kub tas li, lub sijhawm khaws cia ntawm ob n-alkanes nrog cov pa roj carbon n thiab N tuaj yeem qhia raws li hauv qab no:
RI = 100n+100[Nn]*[log t'–log t'n]/[log t'N -log t'n]
t'= t- tm; t'n = tn - tm; t'N = tN- tm yog lub sijhawm tuag.
Cov Ntsuas Kev Khaws Cia nyob rau hauv Qhov Kub thiab Txias uas tau teeb tsa:
Hauv kev teeb tsa uas tau teeb tsa los ntawm qhov kub thiab txias, cov ntsuas kev khaws cia tuaj yeem suav tau los ntawm kev siv lub sijhawm khaws cia tiag tiag es tsis yog siv lawv cov nqi logarithmic: RI = 100n + 100 [Nn] * [t –tn] / [tN - tn]
Cov Yam Uas Cuam Tshuam Rau Kev Khaws Cia Cov Ntaub Ntawv:
Muaj ntau yam uas yuav cuam tshuam rau qhov ntsuas kev khaws cia, suav nrog hom theem ruaj khov siv, qhov kev pab cuam kub, thiab qhov xwm txheej ntawm cov qauv matrix. Kev nkag siab txog cov yam no yog qhov tseem ceeb rau kev tshuaj xyuas zoo.
Txoj Kev Ntsuas Zoo Ob Sab:
Txoj kev no suav nrog kev xam cov ntsuas kev khaws cia ntawm cov khoom sib xyaw ntawm ob theem sib txawv polar stationary. Yog tias ob qho ntsuas kev khaws cia sib xws nrog cov khoom sib xyaw txheem, kev txheeb xyuas qhov zoo ua ntej tuaj yeem ua tiav.
Tshooj 3: Cov Txheej Txheem Tandem Mass Spectrometry
Kev siv Tandem mass spectrometry (MS/MS) ua kom kev tshuaj xyuas zoo dua los ntawm kev tso cai rau kev sib cais ntawm cov ions, muab cov ntaub ntawv ntxiv txog cov qauv. Cov txheej txheem no muaj txiaj ntsig zoo rau cov khoom sib xyaw ua ke, ua rau muaj kev txheeb xyuas cov tshuaj uas yuav tsis pom hauv ib theem ntawm kev ntsuas pawg.
Tshooj 4: Kev Tshawb Fawb Txog MS Zoo Tshaj Plaws
Kev ntsuas qhov hnyav uas muaj qhov daws teeb meem siab muab qhov tseeb thiab kev daws teeb meem zoo dua, ua rau nws yog ib qho cuab yeej muaj txiaj ntsig zoo rau kev tshuaj xyuas zoo. Cov txheej txheem no muaj txiaj ntsig zoo hauv kev paub qhov txawv ntawm cov isomers thiab cov tshuaj sib ze, uas yog qhov tseem ceeb hauv kev tshuaj xyuas cov qauv nyuaj.
Tshooj 5: Kev Tshuaj Xyuas Txog Ion-Molecule GC-MS
Cov tshuaj tiv thaiv ion-molecule hauv GC-MS tuaj yeem muab kev nkag siab txog kev ua haujlwm thiab cov qauv ntawm cov khoom sib xyaw ua ke. Kev teeb tsa tag nrho ntawm cov cuab yeej spectrometry rau kev tshuaj xyuas cov khoom sib xyaw ua ke yog qhov tseem ceeb rau cov txiaj ntsig zoo. Cov tswv yim rau kev tshuaj xyuas cov khoom sib xyaw ua ke feem ntau cuam tshuam nrog kev xaiv cov txheej txheem ionization thiab kev ua kom zoo ntawm cov xwm txheej chromatographic.
Xaus lus, GC-MS yog ib txoj kev siv tshuab uas zoo heev uas sib txuas cov peev xwm sib cais ntawm cov roj chromatography nrog lub zog txheeb xyuas ntawm cov spectrometry. Los ntawm kev siv cov ntaub ntawv khaws cia cov ntaub ntawv mass spectrometry, kev suav cov ntsuas khaws cia, thiab cov txheej txheem siab heev, cov kws tshuaj ntsuam xyuas tuaj yeem ua tiav cov txiaj ntsig zoo, ua rau GC-MS yog ib qho cuab yeej muaj txiaj ntsig zoo hauv ntau yam kev tshawb fawb.
Xov tooj
Xa Email
whatsapp
WeChat 
