Nā Hoʻohana o nā Spectrometer Mass i ka Kemika
ʻO ka spectrometer mass kekahi o nā mea hana loiloi koʻikoʻi loa i ka kemika hou. Hiki i kēia mea hana i nā kānaka ʻepekema ke "ʻike" i ka haku mele ʻana o kahi laʻana e pili ana i nā nui o kona mau ʻāpana, ʻoiai hoʻi nā nui o nā ion. Me ka hiki ke ʻike i nā hui, hoʻoholo i nā ʻano molekala, ana i nā ʻano o nā mea, a ʻike pū i nā mea haumia i nā nui liʻiliʻi loa, ua lilo nā spectrometers mass i iwi kuamoʻo o nā ʻano like ʻole o ke kemika: kemika organik, kemika inorganic, biochemistry, kemika kaiapuni, nā lāʻau lapaʻau, a me nā forensics. Kūkākūkā pōkole kēia ʻatikala i nā loina hana a me nā hoʻohana koʻikoʻi o nā spectrometers mass i ka kemika, a wehewehe i ke kumu he waiwai nui kēia ʻano hana.
Nā Kumumanaʻo Kumu o ka Mass Spectrometry
Hana ka spectrometry mass ma ka hoʻololi ʻana i nā molekala i mau ion, a laila hoʻokaʻawale i nā ion ma muli o kā lākou lakio mass-to-charge (m/z). Ma keʻano laulā, ʻekolu mau ʻāpana nui o ka spectrometer mass: kahi kumu ion, kahi mea kālailai mass, a me kahi mea ʻike.
1. Ionization: Hoʻoikaika ʻia ka hāpana e hana i nā ions. Aia nā ʻano hana ionization like ʻole, me ka Electron Ionization (EI), Electrospray Ionization (ESI), a me Matrix-Assisted Laser Desorption/Ionization (MALDI).
2. Hoʻokaʻawale ʻia ma muli o m/z: Hoʻouna ʻia nā ion ma o kahi mea kālailai nuipa e like me ka quadrupole, time-of-flight (TOF), ion trap, a i ʻole Orbitrap e hoʻokaʻawale ʻia e like me ko lākou waiwai m/z.
3. ʻIke ʻana: Hoʻomaulia ka mea ʻike i ka ikaika o ka ion ma kēlā me kēia waiwai m/z, no laila e hana ana i kahi spectrum nuipa ma ke ʻano o nā piko e hōʻike ana i kekahi mau ion.
Hiki ke manaʻo ʻia kahi spectrum nui he "manamana lima" kemika: he ʻokoʻa kona ʻano piko, ʻoiai ke hui pū ʻia me ka ʻike fragmentation a me nā ʻano hana hoʻokaʻawale e like me chromatography.
1. Ka ʻike ʻana i nā hui a me ka hoʻoholo ʻana i ka nuipa Molekala
ʻO ka hoʻohana maʻamau loa o ka spectrometer mass ka hoʻoholo ʻana i ka nuipa molekala a me ka ʻike ʻana i nā hui. I ka nānā ʻana i nā hui organik, ʻo nā piko e hōʻike ana i nā ion molekala a i ʻole nā adducts (e.g., [M+H]^+ ma ESI) hāʻawi i ka ʻike pololei e pili ana i ka nuipa molekala.
I ka hana maʻamau, ʻike pinepine ʻia ka ʻike ʻana ma o:
- Ke hoʻohālikelike ʻana o nā spectra me nā hale waihona puke spectrum nui, ʻoi aku hoʻi no nā ʻano hana EI ma nā pūhui volatile.
– Ka hoʻoholo pololei ʻana i ka nuipa (MS hoʻonā kiʻekiʻe) e kuhi i nā ʻano molekala e pili ana i nā waiwai nuipa pololei loa.
– Nā ʻano isotope (e.g. he ʻano isotope ko Cl a me Br) e kōkua ana i ka hoʻoholo ʻana i ka haku mele ʻana o nā mea.
He mea koʻikoʻi kēia hiki ke hana nā kānaka noiʻi i nā hui hou: ma mua o ka hoʻomau ʻana i ka nānā hou ʻana, hiki iā lākou ke hōʻoia i ka huahana hopena i loaʻa ka nui kūpono.
2. Ka Wehewehe ʻana i ke ʻAno ma o ka Māhelehele (MS/MS)
Ma waho aʻe o ke ana ʻana i ka nuipa, hiki ke hoʻohana ʻia nā spectrometers nuipa e aʻo i ke ʻano molekala ma o ka fragmentation. Ma kekahi mau ʻano hana, hiki i nā ion molekala ke haki i nā ʻāpana liʻiliʻi. Hāʻawi kēia mau ʻano fragmentation i nā hōʻailona e pili ana i nā hui hana, nā iwi kalapona, a pehea e pili ai nā ʻātoma.
He mea kaulana loa nā ʻano hana tandem mass spectrometry (MS/MS) no ka mea hiki iā lākou ke koho i nā ions kikoʻī (nā ions precursor) a laila ka fragmentation i kāohi ʻia e hana i nā ions fragment (nā ions huahana). Mai kēia, hiki i nā kemika ke:
– E kuhikuhi i ke kūlana o kekahi mau hui i loko o kahi molekala.
– E hoʻokaʻawale ma waena o nā isomers nona ka nuipaʻa molekala like akā nā ʻano like ʻole.
- E kālailai i nā molekala paʻakikī e like me nā peptides, metabolites, a i ʻole nā pūhui kūlohelohe.
I ke kemika organik a me ka biochemistry, hoʻohui pinepine ʻia ʻo MS/MS me nā algorithms hulina e wehewehe i nā ʻāpana, e wikiwiki a ʻōnaehana hoʻi ke kaʻina hana hoʻoholo ʻana i ka hale.
3. Ka Nānā ʻana i nā Huihui Paʻakikī me GC-MS a me LC-MS
ʻAʻole nā laʻana kemika maoli he nui nā hui maʻemaʻe, akā he mau hui paʻakikī. ʻO ka pōmaikaʻi o ka spectrometry mass, hiki ke hoʻohui ʻia me nā ʻano hana hoʻokaʻawale e like me:
– GC-MS (Gas Chromatography–Mass Spectrometry) no nā hui volatile a me thermostable, e like me nā solvents, hydrocarbons, kekahi mau pesticides, a i ʻole nā mea ʻala.
– LC-MS (Liquid Chromatography–Mass Spectrometry) no nā hui non-volatile a thermolabile paha, e like me nā lāʻau lapaʻau, nā metabolites, nā dyes, a me nā biomolecules.
Hoʻokaʻawale ka Chromatography i nā ʻāpana o kahi hui ʻana ma muli o ko lākou manawa paʻa, ʻoiai ʻo MS e kuhikuhi ana i kēlā me kēia ʻāpana ma muli o kona spectrum mass. He ikaika kēia hui ʻana no ka mea:
– Hoʻemi i ka hoʻopili ʻana o nā hōʻailona ma waena o nā hui.
- ʻAe i ka nānā qualitative a me quantitative i hoʻokahi moʻo.
- Hoʻonui ʻia ka ʻike a me ke koho ʻana i hoʻohālikelike ʻia me nā ʻano hana hoʻokahi.
I ke kemika analytical, ʻo GC-MS a me LC-MS nā kūlana no nā hoʻāʻo maʻamau a me nā hoʻāʻo noiʻi.
4. Ka helu ʻana: Ke ana pololei ʻana i ka ʻike o nā mea
ʻAʻole hoʻohana wale ʻia ka spectrometry mass e "ʻike" i nā hui, akā e ana pū i ko lākou nui me ka ʻike kiʻekiʻe. I nā hihia he nui, hiki iā MS ke ʻike i nā hui ma nā pae trace, e like me nā nanograms no ka lita a i ʻole ka haʻahaʻa, ʻoiai ke hoʻohana nei i nā ʻano nānā koho.
Hoʻohana pinepine ka helu ʻana me MS i:
– Nā kūlana kūloko (pinepine ʻia ka isotope i kapa ʻia) e hoʻoponopono no nā ʻokoʻa injection a me nā hopena matrix.
– Ke kūlou hoʻoponopono e hoʻopili i ka ikaika o ka hōʻailona i ka noʻonoʻo ʻana.
– Nā ʻano ʻike kuhikuhi e like me SIM/MRM (ma ka quadrupole a i ʻole triple quadrupole) e hoʻonui i ke koho ʻana.
He mea nui loa kēia mau pono i ka lāʻau lapaʻau, toxicology, a me ka nānā ʻana i ke kaiapuni, kahi e pono ai nā palena ʻike haʻahaʻa a me ka pololei kiʻekiʻe.
5. Nā noi ma ke Kemika lāʻau lapaʻau a me ka ʻike ʻana i nā lāʻau lapaʻau
I ka hoʻomohala ʻana i nā lāʻau lapaʻau, hoʻohana ʻia nā spectrometers mass mai nā pae mua a hiki i ka kaohi maikaʻi. Eia kekahi laʻana:
– Ka ʻike ʻana a me ke ʻano o nā moho lāʻau lapaʻau: e hōʻoia ana i ka hoʻonohonoho ʻana a me ka maʻemaʻe.
– Nā haʻawina metabolic: ka ʻike ʻana i nā metabolites lāʻau lapaʻau i loko o ke koko a i ʻole ka mimi, ka loiloi ʻana i nā ala biotransformation.
– Hoʻāʻo kūpaʻa: ka nānā ʻana i nā huahana hōʻino ma muli o ka mālamalama, ka wela, a i ʻole ka pH.
– Ka hoʻoholo ʻana i nā haumia: ka ʻike ʻana i nā haumia ma nā pae liʻiliʻi loa e hiki ke hoʻopilikia i ka palekana.
He mea hana hilinaʻi loa ʻo LC-MS/MS no ka mea hiki iā ia ke kālailai i nā hui lāʻau lapaʻau i polar pinepine a paʻakikī, a hana maikaʻi i nā matrices biological.
6. Kemika Kaiapuni: Ka ʻIke ʻana i nā Mea Hoʻohaumia a me nā Mea Hoʻohaumia
Pono ke kahua o ke kemika kaiapuni i nā ʻano hana e hiki ai ke ʻike i nā mea haumia ma nā pae haʻahaʻa loa. Hoʻohana ʻia nā spectrometers mass i:
– Ke ana ʻana i nā pesticides, nā herbicides, a me kā lākou huahana palaho i ka wai a me ka lepo.
- Ke ʻike ʻana i nā metala kaumaha a me ka hoʻokaʻawale ʻana o nā mea (me nā ʻano hana kikoʻī e like me ICP-MS no nā mea).
– Ka nānā ʻana i nā pūhui organik mau loa e like me nā PCB, dioxins, a i ʻole PAHs.
- Ke nānā ʻana i nā mea haumia e kū mai ana e like me nā koena lāʻau lapaʻau, nā mea haumia micro, a me nā pūhui perfluoroalkyl.
Me ka ʻikepili pololei, hiki i nā mea noiʻi ke loiloi i nā kumu haumia, ka hoʻolaha ʻana, a me nā pilikia i ke olakino a me nā ʻōnaehana ola.
7. Biochemistry a me Proteomics: Ke kālailai ʻana i nā Biomolecules nui
ʻO nā ʻano hana ionization palupalu e like me ESI a me MALDI e wehe i ka puka i ka nānā ʻana i nā molekala nui e like me nā protein, peptides, a me nā oligonucleotides. I loko o ka biochemistry, hoʻohana ʻia ka mass spectrometry i:
– Proteomics: ke ʻike ʻana i nā protein i loko o nā hui paʻakikī, ke kaha kiʻi ʻana i nā hoʻololi ma hope o ka unuhi ʻana (e.g. phosphorylation).
– Metabolomics: ke kaha kiʻi ʻana i nā ʻikepili metabolite e hoʻomaopopo ai i nā kūlana physiological a i ʻole nā maʻi.
– E hoʻoholo i ka nuipa a me ka heterogeneity o nā biomolecules (e.g. glycosylation).
Hōʻike kēia kuleana ʻaʻole i kaupalena ʻia ka pono o nā spectrometers mass i ka kemika "maʻemaʻe", akā ua lilo pū ia i mea hana koʻikoʻi i nā ʻepekema ola molekala.
8. Kemika Forensic a me ka Palekana Meaʻai
Hoʻohana nui ʻia nā spectrometers Mass i nā forensics no:
- Ke ʻike ʻana i nā narcotics, nā mea psychoactive hou, a me kā lākou metabolites.
– Ka nānā ʻana i ka lāʻau make, ka waiʻona, a i ʻole nā mea pahū.
– Ka hōʻoia ʻana o ka ʻoiaʻiʻo o ka laʻana a me ka huli ʻana i nā kumu kemika.
Ma ka palekana meaʻai, kōkua ʻo MS i ka hoʻāʻo ʻana:
– Nā koena pesticides ma luna o nā huaʻai a me nā mea kanu.
– Nā mea haumia e like me ka melamine, mycotoxins, a i ʻole nā mea hui kū ʻole i ke kānāwai.
– Ka ʻoiaʻiʻo o ka huahana (e.g. nā ʻano kikoʻī e hoʻokaʻawale i ka hoʻopunipuni).
ʻO kona mau pono ka koho kiʻekiʻe, nā hiki hōʻoia, a me ka ʻike e kū nei i nā kūlana hoʻoponopono.
Ka hopena
He nui nā hoʻohana ʻana o nā spectrometers mass i ka kemika: mai ka ʻike ʻana i ka hui, ka hoʻoholo ʻana i ka nui o ka molekala, ka wehewehe ʻana i ke ʻano ma o ka fragmentation, ka loiloi hui ʻana me GC-MS/LC-MS, ka helu ʻana o nā pae waiwai, a hiki i nā noi kūikawā i nā lāʻau lapaʻau, ke kaiapuni, biochemistry, forensics, a me ka palekana meaʻai. ʻO ka hui pū ʻana o ke ʻano kiʻekiʻe, ke koho ʻana, a me ka maʻalahi i nā ʻano ionization a me ka loiloi nui e hoʻolilo i kēia mea hana i "mea hana multi-purpose" no nā chemists.
Inā makemake ʻia, hiki ke hoʻomohala hou ʻia kēia ʻatikala me nā mokuna kikoʻī ma nā ʻano ionization (EI, ESI, MALDI), nā ʻano mea kālailai nuipa (quadrupole, TOF, Orbitrap), a me nā hiʻohiʻona honua maoli mai kēlā me kēia kahua noi.
