SPE tau nyob ib ncig ntawm kaum xyoo, thiab rau qhov laj thawj zoo. Thaum cov kws tshawb fawb xav kom tshem tawm cov keeb kwm yav dhau los ntawm lawv cov qauv, lawv tau ntsib nrog kev sib tw ntawm kev ua li ntawd yam tsis txo lawv lub peev xwm los txiav txim siab qhov tseeb thiab qhov muaj nuj nqis ntawm lawv qhov kev txaus siab. SPE yog ib qho txheej txheem uas cov kws tshawb fawb feem ntau siv los pab npaj lawv cov qauv rau cov cuab yeej rhiab siv rau kev tshuaj xyuas ntau. SPE muaj zog, ua haujlwm rau ntau hom qauv, thiab SPE cov khoom tshiab thiab cov txheej txheem txuas ntxiv tsim. Lub hauv paus ntawm kev tsim cov qauv no yog qhov txaus siab tias txawm tias lo lus "chromatography" tsis tshwm sim hauv cov txheej txheem lub npe, SPE tseem yog ib qho kev sib cais ntawm chromatographic.

SPE: Lub Silent Chromatography

Muaj ib lo lus qub hais tias, "Yog tsob ntoo poob hauv hav zoov, tsis muaj leej twg nyob ib puag ncig hnov ​​nws, nws puas tseem ua suab?" Cov lus ntawd ua rau peb nco txog SPE. Qhov ntawd yuav zoo li hais txawv txawv, tab sis thaum peb xav txog SPE, cov lus nug dhau los "yog tias muaj kev sib cais thiab tsis muaj lub tshuab ntes nyob rau ntawd los sau nws, puas yog chromatography tiag tiag?" Nyob rau hauv cov ntaub ntawv ntawm SPE, cov lus teb yog ib tug resounding "yog!" Thaum txhim kho lossis daws teeb meem SPE txoj kev, nws tuaj yeem pab tau kom nco ntsoov tias SPE tsuas yog chromatography tsis muaj chromatogram. Thaum koj xav txog nws, tsis yog Mikhail Tsvet, lub npe hu ua "leej txiv ntawm chromatography," ua qhov peb yuav hu ua "SPE" hnub no? Thaum nws cais nws cov khoom sib xyaw ntawm cov xim cog los ntawm kev cia lub ntiajteb txawj nqus nqa lawv, yaj hauv cov kuab tshuaj, los ntawm ib lub txaj hauv av, nws puas txawv dua li txoj kev SPE niaj hnub no?

Nkag siab koj tus qauv

Txij li thaum SPE yog raws li cov hauv paus ntsiab lus ntawm chromatographic, nyob rau hauv lub plawv ntawm txhua txoj kev zoo SPE yog kev sib raug zoo ntawm cov analytes, lub matrix, nyob ruaj ruaj theem (SPE sorbent), thiab lub mobile theem (cov kuab tshuaj siv los ntxuav los yog elute tus qauv) .

Nkag siab qhov xwm txheej ntawm koj tus qauv kom ntau li ntau tau yog qhov zoo tshaj plaws los pib yog tias koj yuav tsum tsim lossis teeb meem ib txoj kev SPE. Txhawm rau zam qhov tsis tsim nyog sim thiab ua yuam kev thaum txoj kev txhim kho, kev piav qhia ntawm lub cev thiab tshuaj lom neeg ntawm ob qho tib si koj cov tshuaj ntsuam xyuas thiab cov matrix yog qhov muaj txiaj ntsig zoo. Thaum koj paub txog koj tus qauv, koj yuav nyob hauv txoj haujlwm zoo dua kom phim cov qauv ntawd nrog cov khoom tsim nyog SPE. Piv txwv li, paub qhov txheeb ze polarity ntawm cov analytes piv rau ib leeg thiab cov matrix tuaj yeem pab koj txiav txim siab yog tias siv polarity cais cov analytes los ntawm matrix yog txoj hauv kev. Paub seb koj qhov kev txheeb xyuas puas yog nruab nrab lossis tuaj yeem muaj nyob hauv cov xeev them nqi kuj tseem tuaj yeem pab coj koj mus rau SPE cov khoom lag luam tshwj xeeb hauv kev khaws lossis tshem tawm qhov nruab nrab, raug nqi zoo, lossis cov nqi tsis zoo. Ob lub ntsiab lus no sawv cev rau ob qho ntawm cov khoom siv tshuaj ntsuam xyuas feem ntau siv los ua kom muaj zog thaum tsim SPE txoj hauv kev thiab xaiv cov khoom SPE. Yog tias koj tuaj yeem piav qhia koj cov kev txheeb xyuas thiab cov ntsiab lus tseem ceeb hauv cov ntsiab lus no, koj nyob ntawm koj txoj hauv kev los xaiv qhov kev taw qhia zoo rau koj txoj kev txhim kho SPE.

Sib cais los ntawm Affinity

Cov hauv paus ntsiab lus uas txhais cov kev sib cais uas tshwm sim hauv LC kem, piv txwv li, yog nyob rau hauv kev sib cais SPE. Lub hauv paus ntawm kev sib cais ntawm chromatographic yog tsim kom muaj kev sib txawv ntawm kev sib cuam tshuam ntawm cov khoom ntawm cov qauv thiab ob theem tam sim no nyob rau hauv kem lossis SPE cartridge, theem mobile thiab theem nyob ruaj khov.

Ib qho ntawm thawj cov kauj ruam ntawm kev zoo siab nrog SPE txoj kev txhim kho yog kom muaj kev paub txog ob hom kev sib cuam tshuam feem ntau ua haujlwm hauv SPE sib cais: polarity thiab / lossis lub xeev them nqi.

Polarity

Yog tias koj yuav siv polarity los ntxuav koj cov qauv, ib qho ntawm thawj qhov kev xaiv uas koj yuav tsum tau ua yog txiav txim siab seb "hom" zoo tshaj. Nws yog qhov zoo tshaj plaws los ua hauj lwm nrog ib tug kuj polar SPE nruab nrab thiab ib tug kuj nonpolar mobile theem (xws li ib txwm hom) los yog qhov opposite, ib tug kuj nonpolar SPE nruab nrab ua ke nrog ib tug kuj polar mobile theem (ie reversed hom, thiaj li hu ua vim nws yog qhov opposite. ntawm qhov pib tsim "hom qub").

Thaum koj tshawb txog SPE cov khoom, koj yuav pom tias cov theem SPE muaj nyob rau hauv ntau qhov polarities. Tsis tas li ntawd, qhov kev xaiv ntawm mobile theem hnyav kuj muaj ntau yam polarities, feem ntau tunable heev los ntawm kev siv cov blends ntawm cov kuab tshuaj, buffers, los yog lwm yam additives. Nws muaj qhov zoo ntawm qhov ua tau zoo thaum siv qhov sib txawv polarity raws li tus yam ntxwv tseem ceeb rau kev siv los cais koj cov kev txheeb xyuas los ntawm kev cuam tshuam ntawm matrix (lossis ntawm ib leeg).

Cia li nco ntsoov cov qub chemistry adage "zoo li yaj zoo li" thaum koj xav txog polarity li tus tsav tsheb sib cais. Qhov sib npaug ntau dua yog qhov polarity ntawm lub xov tooj ntawm tes los yog nyob ruaj ruaj, nws yuav muaj kev cuam tshuam ntau dua. Kev sib cuam tshuam muaj zog nrog rau theem nyob ruaj khov ua rau muaj kev tuav pov hwm ntev dua ntawm SPE nruab nrab. Kev sib cuam tshuam zoo nrog rau theem mobile ua rau muaj kev tuav pov hwm tsawg dua thiab ua ntej elution.

Charge State

Yog tias cov kev txheeb xyuas ntawm kev txaus siab ib txwm muaj nyob hauv lub xeev them nyiaj lossis tuaj yeem muab tso rau hauv lub xeev them nyiaj los ntawm cov xwm txheej ntawm cov tshuaj uas lawv tau yaj hauv (xws li pH), ces lwm txoj kev muaj zog ntawm kev sib cais ntawm cov matrix (los yog txhua lwm yam) yog los ntawm kev siv SPE xov xwm uas tuaj yeem nyiam lawv nrog tus nqi ntawm lawv tus kheej.

Nyob rau hauv cov ntaub ntawv no, classic electrostatic attraction txoj cai siv. Tsis zoo li kev sib cais uas tso siab rau cov yam ntxwv polarity thiab "zoo li yaj zoo li" qauv ntawm kev sib cuam tshuam, kev cuam tshuam hauv lub xeev tau ua haujlwm ntawm txoj cai ntawm "kev tawm tsam nyiam." Piv txwv li, koj tuaj yeem muaj qhov nruab nrab SPE uas muaj tus nqi zoo ntawm nws qhov chaw. Txhawm rau sib npaug qhov zoo ntawm qhov chaw them nqi, feem ntau yog cov tsiaj tsis zoo (ib qho anion) pib khi rau nws. Yog tias koj qhov kev ntsuas qhov tsis zoo tau nkag mus rau hauv lub kaw lus, nws muaj peev xwm hloov pauv qhov pib khi anion thiab cuam tshuam nrog qhov zoo ntawm SPE nto. Qhov no ua rau muaj kev tuav pov hwm cov tshuaj ntsuam xyuas ntawm SPE theem. Qhov kev sib pauv ntawm cov anions no yog hu ua "Anion Exchange" thiab tsuas yog ib qho piv txwv ntawm cov khoom dav dav ntawm "Ion Txauv" SPE cov khoom. Hauv qhov piv txwv no, cov tsiaj raug nqi zoo yuav muaj kev txhawb zog kom nyob twj ywm rau hauv theem mobile thiab tsis cuam tshuam nrog qhov zoo ntawm SPE nto, yog li lawv yuav tsis khaws cia. Thiab, tshwj tsis yog tias SPE nto muaj lwm yam ntxwv ntxiv rau nws cov khoom sib pauv ion, cov kab nruab nrab kuj tseem yuav khaws cia tsawg kawg nkaus (txawm hais tias, cov khoom siv SPE zoo li no muaj nyob, tso cai rau koj siv ion pauv thiab thim rov qab cov txheej txheem khaws cia hauv tib qhov nruab nrab SPE. ).

Ib qho tseem ceeb sib txawv kom nco ntsoov thaum siv ion exchange mechanisms yog qhov xwm txheej ntawm tus nqi ntawm cov tshuaj ntsuam xyuas. Yog tias cov tshuaj ntsuam xyuas ib txwm raug them, tsis hais qhov pH ntawm cov tshuaj nws nyob hauv, nws raug suav tias yog hom "muaj zog". Yog tias qhov ntsuas tsuas yog them raws li qee qhov pH, nws suav tias yog hom "tsis muaj zog". Qhov ntawd yog tus cwj pwm tseem ceeb kom nkag siab txog koj cov kev txheeb xyuas vim tias nws yuav txiav txim siab seb hom SPE media yuav siv li cas. Hauv cov ntsiab lus dav dav, kev xav txog kev sib txawv ntawm kev sib koom ua ke yuav pab tawm ntawm no. Nws yog ib qho tsim nyog los ua ke ib qho tsis muaj zog ion pauv SPE sorbent nrog "muaj zog" hom thiab muaj zog ion pauv sorbent nrog "tsis muaj zog" tshuaj ntsuam xyuas.