Mashandisirwo eMass Spectrometers muKemistri
Chiyero chemass spectrometer chimwe chezvishandiso zvakakosha zvekuongorora mumakemikari emazuva ano. Chishandiso ichi chinobvumira masayendisiti "kuona" kuumbwa kwemuenzaniso zvichibva pahuwandu hwezvikamu zvayo, kunyanya huwandu hwemaion. Nekukwanisa kuona makemikari, kuona maumbirwo emamorekuru, kuyera huwandu hwezvinhu, uye kunyange kuona tsvina muhuwandu hushoma, mass spectrometers ave musimboti wenzvimbo dzakasiyana dzekemistri: organic chemistry, inorganic chemistry, biochemistry, environmental chemistry, pharmaceuticals, uye kunyange forensics. Chinyorwa chino chinokurukura muchidimbu misimboti yekushanda uye mashandisirwo akakosha emass spectrometers mukemistri, uye chinotsanangura kuti sei nzira iyi ichikosha kudaro.
Nheyo dzekutanga dzeMass Spectrometry
Kuyera ma spectrometry kunoshanda nekushandura mamorekuru kuita ma ions, wobva waparadzanisa ma ions zvichibva pahuwandu hwavo hwe mass-to-charge (m/z). Kazhinji, mass spectrometer ine zvikamu zvitatu zvikuru: source ye ion, mass analyzer, uye detector.
1. Kuisa maion: Muenzaniso wacho unopihwa simba rekugadzira maion. Kune nzira dzakasiyana dzekuisa maion, dzinosanganisira Electron Ionization (EI), Electrospray Ionization (ESI), uye Matrix-Assisted Laser Desorption/Ionization (MALDI).
2. Kupatsanurwa kwakavakirwa pa m/z: MaIon anopfuudzwa nemuchina wekuongorora mass akadai se quadrupole, time-of-flight (TOF), ion trap, kana Orbitrap kuti apatsanurwe zvichienderana nehukuru hwawo hwe m/z.
3. Kuona: Chinoongorora chinoverenga simba remaion pahuwandu hwese hwe m/z, nokudaro chichigadzira huwandu hwakawanda hwemaion muchimiro chemakomo anomiririra mamwe maion.
Hunhu hwemasasi hunogona kufungidzirwa se "fingerprint" yemakemikari: maitiro ayo epamusoro akasiyana, kunyanya kana akabatanidzwa neruzivo rwekupatsanurwa uye matekiniki ekuparadzanisa akadai se chromatography.
1. Kuzivikanwa kweMakomponi uye Kusarudzwa kweMamorekuru
Kushandiswa kwakanyanya kwe "mass spectrometer" ndekwekuona huwandu hwe "molecular mass" uye kuona makemikari. Mukuongorora makemikari e "organic compounds", peaks dzinomiririra ma "molecule ions" kana "adducts" (semuenzaniso, [M+H]^+ muESI) dzinopa ruzivo rwakananga nezvehuwandu hwe "molecular mass".
Mukuita, kuzivikanwa kunowanzoitwa kuburikidza ne:
- Kuenzanisa maspectra nemaraibhurari espectrum akawanda, kunyanya matekiniki eEI pamakomponi anoshanduka.
- Kuona huwandu hwacho nemazvo (MS ine resolution yepamusoro) kuti ufungidzire mafomura emamorekuru zvichibva pahuwandu hwacho hwakanyatsojeka.
– Mapatani eIsotope (semuenzaniso Cl naBr ane mapatani eisotope akasiyana) ayo anobatsira kuona kuumbwa kwezvinhu.
Kugona uku kwakakosha kana vaongorori vachigadzira mishonga mitsva: vasati vaenderera mberi nekuongorora, vanogona kusimbisa kuti chigadzirwa chinobuda chine huremu hwakakodzera.
2. Kujekesa Maumbirwo Kuburikidza Nekupatsanurwa (MS/MS)
Pamusoro pekuyera huremu, ma spectrometer ehukuru anogona kushandiswa kudzidza chimiro chemamorekuru kuburikidza nekupatsanuka. Mune dzimwe nzira, ma ion emamorekuru anogona kupatsanuka kuita zvidimbu zvidiki. Mapatani aya ekupatsanuka anopa zviratidzo nezvemapoka anoshanda, mapuraneti ekabhoni, uye kuti maatomu akabatana sei.
Matekiniki eTandem mass spectrometry (MS/MS) anozivikanwa zvikuru nekuti anobvumira kusarudzwa kwemaion chaiwo (precursor ions) uye ozodzora kupatsanurwa kuti agadzire maion akapatsanurwa (product ions). Kubva pane izvi, machemist anogona:
- Kuziva nzvimbo yemapoka akati wandei mumorekuru.
- Siyanisa pakati pema isomers ane mamorekuru akafanana asi maumbirwo akasiyana.
- Ongorora mamorekuru akaomarara akadai semapeptide, metabolites, kana makemikari echisikigo.
Mumakemikari echisikigo nemakemikari echisikigo, MS/MS inowanzo sanganiswa nemaalgorithms ekutsvaga kuti atsanangure zvidimbu, zvichiita kuti maitiro ekusarudza chimiro akurumidze uye arongeke zvakanyanya.
3. Kuongororwa kweComplex Mixtures neGC-MS neLC-MS
Mienzaniso yakawanda yemakemikari chaiwo haisi mishonga chaiyo, asi misanganiswa yakaoma kunzwisisa. Chakanakira mass spectrometry ndechekuti inogona kusanganiswa nenzira dzekuparadzanisa dzakadai se:
– GC-MS (Gas Chromatography–Mass Spectrometry) yemakemikari anoshanduka-shanduka uye anodziya, akadai sezvinonyungudutsa, mahydrocarbon, mimwe mishonga yezvipembenene, kana zvinhu zvinonhuhwirira.
– LC-MS (Liquid Chromatography–Mass Spectrometry) yemakemikari asingachinji kana kuti anodziya muviri, akadai semishonga, metabolites, dyes, uye biomolecules.
Chromatography inopatsanura zvikamu zvemusanganiswa zvichienderana nenguva yazvo yekuchengetedzwa, nepo MS ichiratidza chikamu chimwe nechimwe zvichienderana nehuwandu hwacho. Musanganiswa uyu une simba nekuti:
- Inoderedza kupindirana kwemasaini pakati pemakemikari.
- Inobvumira ongororo yemhando yepamusoro uye yehuwandu mune imwe nhevedzano.
- Kuwedzera kwekunzwa uye kusarudza kana tichienzanisa nenzira imwe chete.
Mukuongorora kemesitiri, GC-MS neLC-MS ndizvo zvinodiwa pakuongorora kwemaitiro nekutsvaga.
4. Kuyera huwandu hwezvinhu: Kuyera huwandu hwezvinhu nemazvo
Kuyera huwandu hwemakemikari mumuviri hakungoshandiswi chete "kuona" macompounds, asiwo kuyera huwandu hwawo nehukuru hwepfungwa. Kazhinji, MS inokwanisa kuona macompounds pamazinga etrace, akadai se nanograms pa litre kana pasi, kunyanya kana uchishandisa nzira dzekutarisa dzakasarudzwa.
Kuongororwa kweropa neMS kunowanzo shandiswa:
- Mipimo yemukati (inowanzo nyorwa se isotope) yekugadzirisa kusiyana kwejekiseni uye mhedzisiro yematrix.
- Kukombama kwekuenzanisa kunobatanidza simba rechiratidzo nekutarisa.
- Nzira dzekuona mafambiro akaita seSIM/MRM (pa quadrupole kana triple quadrupole) kuwedzera kusarudza.
Mabhenefiti aya anonyanya kukosha mukurapa, kuongorora chepfu, uye kuongorora zvakatipoteredza, uko kunodiwa miganhu shoma yekuona uye kunyatsoita zvinhu nemazvo.
5. Mashandisirwo muMishonga Chemistry uye Kuwanikwa Kwemishonga
Mukugadzirwa kwemishonga, mass spectrometer anoshandiswa kubva padanho rekutanga kusvika pakudzora mhando. Semuenzaniso:
- Kuzivikanwa uye kutsanangurwa kwevaya vanoshandisa zvinodhaka: kuona kuti zvinhu zviri muchimiro uye kuti hazvina kuchena.
- Zvidzidzo zveMetabolic: kuona metabolites yemishonga muropa kana weti, kuongorora nzira dzebiotransformation.
- Kuyedzwa kwekugadzikana: kutarisa zvinhu zvinoora nekuda kwechiedza, kupisa, kana pH.
- Kuziva tsvina: kuona tsvina padanho diki diki rinogona kukanganisa kuchengetedzeka.
LC-MS/MS chishandiso chakavimbika zvikuru nekuti chinokwanisa kuongorora mishonga inowanzova polar uye yakaoma, uye inoshanda zvakanaka mu biological matrices.
6. Kemikari Yezvakatipoteredza: Kuona Zvinosvibisa Nezvinosvibisa
Basa remakemikari ezvakatipoteredza rinoda nzira dzinokwanisa kuona kusvibiswa kwemhepo padanho rakaderera zvikuru. Mass spectrometers anoshandiswa ku:
- Kuyera mishonga yezvipembenene, mishonga yekuuraya zvipembenene, uye zvinokuvadza zvinogadzirwa mumvura nevhu.
- Kuona simbi dzinorema uye zvinhu zvakasiyana-siyana (nenzira dzakatarwa dzakadai seICP-MS yezvinhu).
- Kuongororwa kwezvinhu zvinogara zviripo zvakaita sePCBs, dioxins, kana PAHs.
- Kutarisa zvinhu zvinosvibisa zviri kubuda zvakaita semishonga, zvinhu zvinosvibisa, uye zvinhu zvinosvibisa zve perfluoroalkyl.
Neruzivo rwakarurama, vaongorori vanogona kuongorora manyuko ekusvibiswa, kupararira, uye njodzi kuhutano nenharaunda.
7. Biochemistry neProteomics: Kuongorora MaBiomolecule Makuru
Nzira dze ionization dzakapfava dzakadai se ESI ne MALDI dzinovhura mukana wekuongorora mamorekuru makuru akadai se mapuroteni, ma peptide, uye oligonucleotides. Mu biochemistry, mass spectrometry inoshandiswa ku:
– Proteomics: kuona mapuroteni mumisanganiswa yakaoma, kugadzira mapani ekuchinja mushure mekushandurwa (semuenzaniso phosphorylation).
– Metabolomics: kugadzira ma profiles emetabolite kuti tinzwisise mamiriro emuviri kana zvirwere.
- Tsvaga huremu uye kusiyana kwezvipenyu zvema "biomolecules" (semuenzaniso glycosylation).
Basa iri rinoratidza kuti kushanda kwema spectrometer ehukuru hakungogumiri pa "kemikari" chete, asi kwavewo chishandiso chakakosha musainzi yehupenyu hwemamorekuru.
8. Chemistry yeForensic uye Kuchengetedzwa kweChikafu
Mass spectrometer anoshandiswa zvakanyanya mu forensics kune:
- Kuona zvinodhaka, zvinhu zvitsva zvinokanganisa pfungwa, uye metabolites yazvo.
- Kuongororwa kwechepfu, doro, kana zvinoputika.
- Kusimbiswa kwechokwadi chemuenzaniso uye kuteverwa kwemakemikari.
Pakuchengetedzeka kwechikafu, MS inobatsira kuyedza:
– Zvinosara zvemishonga inouraya zvipembenene pamichero nemiriwo.
– Zvinhu zvinosvibisa zvakaita semelamine, mycotoxins, kana zvinhu zvisiri pamutemo.
– Kuve kwechokwadi kwechigadzirwa (semuenzaniso mapurofayi chaiwo ekusiyanisa kusvibiswa).
Zvakanakira zvayo isarudzo yepamusoro, kugona kusimbisa, uye kunzwa kunoenderana nemitemo.
Mhedziso
Mashandisirwo ema "mass spectrometers" mumakemikari akasiyana-siyana: kubva pakuzivikanwa kwema "compound", kuona huwandu hwema "molecular mass", kutsanangurwa kwechimiro kuburikidza nekupatsanurwa, kuongororwa kwemusanganiswa neGC-MS/LC-MS, kuverengwa kwemazinga echinhu, kusvika pakushandiswa kwakakosha mumishonga, nharaunda, biochemistry, forensics, uye kuchengetedzeka kwechikafu. Kubatanidzwa kwe "high sensitivity", kusarudza, uye kushanduka-shanduka mu ionization uye nzira dzekuongorora huwandu kunoita kuti chishandiso ichi chive "chishandiso chemabasa akawanda" chevanyanzvi vemakemikari.
Kana uchida, chinyorwa chino chinogona kusimudzirwa nezvikamu zvidiki zvakananga pamusoro pemhando dzeionization (EI, ESI, MALDI), mhando dzema mass analyzer (quadrupole, TOF, Orbitrap), pamwe chete nemienzaniso chaiyo kubva muchikamu chega chega chekushandisa.
