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2. K thut phn tch hiu qu chnh xc cao K thut phn mnh Rt hu hiu xc nh cu to ca cc hp cht 3. Lch s hnh thnh phng php khi ph Nhng nh nghin cu tin phong Phng php khi ph Ni dung Phn tch cu trc v kiu phn mnh Gii thch khi ph ng dng phng php khi ph 4. 1897 1919 1934 1966 J.J. Thomson. Discovered electrons by cathode rays experiment. Nobel prize in 1906. Francis Aston recognized 1st mass spectrometer and measure z/m of ionic compounds. First double focusing magnetic analyzer was invented by Johnson and Neil. Munson and Field described chemical ionization. Brief History of Mass Spectrometry 5. 1968 1975 1985 1989 Electrospray Ionization was invented by Dole, Mack and friends. Atmospheric Pressure Chemical Ionization (APCI) was developed by Carroll and others. F. Hillenkamp, M.Karas and co-workers describe and coin the term matrix assisted laser desorption ionization (MALDI). w. Paul discovered the ion trap technique. 6. Joseph John Thomson 1906 Nobel Prize for Physics (theoretical and experimental investigations on the conduction of electricity by gases) Francis William Aston 1922 Nobel Prize for Chemistry (mass spectrograph, of isotopes, in a large number of non-radioactive elements) Wolfgang Paul 1989 Nobel Prize for Physics (for the development of the ion trap technique) John Bennet Fenn 2002 Nobel Prize for Chemistry (for the development of Soft Desorption ionization Method) Koichi Tanaka 2002 Nobel Prize for Chemistry (mass spectrometric analyses of biological macromolecule s) Nobel prize pioneers 7. Mass spectrometer 8. L thuyt Mass Spectrometry Trong mass spectrometer, Cc hin tng u xy ra tun t nh nhau, ngoi tr cc nguyn t v phn t b tch ra khi i qua in trng v t trng. Tin trnh ny xy ra trong khng gian nh. 9. Mass spectrometer ging nh lng knh. Trong lng knh, nh sng l c phn tch thnh nhng thnh phn khc nhau da trn bc sng ca chng. V ri nhng bc x ny c xc nh thng qua s tng tc detector chuyn ha thnh nhng tnh hiu v in. Tng t nh trong mass spectrometer cc ion c tch bng s khc nhau v khi lng v cng c xc nh bi detector ion. 10. NIST/EPA/NIH Mass Spectral Library 2005 By U.S. Department of Commerce Publisher: Wiley Number Of Pages: Publication Date: 2005-07-22 ISBN-10 / ASIN: 047175594X ISBN-13 / EAN: 9780471755944 Binding: CD-ROM NIST/EPA/NIH Mass Spectral Library is the most popular library for GC/MS instruments, with 190,825 spectra presented. This software offers: * 190,825 EI Mass Spectra * 163,198 compounds, 163,195 structures * 121,112 Retention indices of 25,983 Compounds * 5,191 MSMS Spectra * Spectral search and analysis software Nhng phn mnh thu c t qu trnh ion ha hnh thnh ph khi ca cht ban u. Qu trnh i chiu,so snh ph khi thu c vi d liu t ngn hng ph hay th vin ph nh danh cht cn quan tm 11. Cc thnh phn c bn ca Mass Spectrometer C bn thnh phn c bn B phn dn mu Ngun ion ha B phn phn tch khi lng cc ion Ion detector 12. Thit b ph khi lng lm 3 nhim v chnh: + Chuyn cht nghin cu thnh th kh ( lm bay hi mu p sut thp v nhit thch hp. + To ra cc ion t cc phn t kh + Phn tch cc ion ri ghi li tn hiu theo t s M/z.e. V xc sut tm thy z > 1 l rt nh v in tch ca in t l 1 nn M chnh l khi lng ca cc ion Thit b ph khi lng l sn xut ra ion v xc nh khi lng ca chng 13. Mass spectrometer Sample Introduction Techniques Initial pressure of sample is 760 mmHg or ~10-6 torr K thut a mu trc tip (Thng dng trong MALDI) K thut dn mu (Thng dng trong ESI) C hai techniques 14. Mass spectrometer Direct Insertion sample introduction technique L mt k thut n gin. Mu c ly bng syringe t bit v tim thng vo bung ion ha. Sau l nhng tc ng cho qu trnh gii hp nh gii hp bng laser hay gia nhit to iu kin ha hi v ion ha.. 15. Direct infusion or injection sample introduction technique Thng xuyn c s dng c c hiu qu cao. Dng trong k thut kt ni nh GC-MS and HPLC-MS 16. Ionization Methods used in Mass spectrometry Thng dng: Proton ha Kh proton ha Cation ha Transfer of a charged molecule to the gas phase Phng (bc) in t By in t 17. Protonation + S hnh thnh cc ion dng bng cch cng H+ + S dng trong cc cht cha cc nhm amin , nhng lin kt peptide + S dng trong k thut MALDI, APCI and ESI 18. Deprotonation + Mt proton H+ c kh ra khi hp cht to mt anion. + S dng cho mu acid nh phenols, carboxylic acid, sulfonic acid etc. + Dng trong MALDI, APCI and ESI 19. Cationization Hnh thnh mt ion phc bng cch cng hp mt cation kim loi vo phn t trung ha nh Na+ , K+ , NH4 + Thng dng i vi Carbohydrates Dng trong cc k thut MALDI, APCI and ESI 20. Transfer of a charged molecule to the gas phase Cation c chuyn t pha lng sang pha kh S dng trong MALDI or ESI 21. K thut phng Electron Electron c phng ra hnh thnh ion dng. Thng l nhng hp cht khng phn cc c khi lng phn t thp nh anthracene. 22. K thut by Electron (EC) Mt in tch m tch in tr 1 c hnh thnh do qu trnh hp thu hay gi mt in t. K thut s dng cho cc hp cht halogen 23. Ngun Ionization Ngun ionization cng ( HIS) Ngun ionization mm (SIS) Dng nng lng ln phn tch phn t thnh nhiu mnh nh bn vng. Nhng mnh ny khng c s phn tch tip theo. S dng mt nng lng nh tch phn t thnh nhng mnh khng bn c th tip tc phn tch 24. Electron Ionization (EI) Chemical Ionization (CI) Electrospray Ionization (ESI) Nanoelectrospray Ionization (NanoESI) Atmospheric Pressure Chemical Ionization (APCI) Atmospheric pressure photoionization (APPI) Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) Fast Atom Bombardment (FAB) Thermal ionization (TI) Cc ngun ion ha trong mass spectrometer 25. Nng lng c cung cp nung nng dy tc kim loi, lm pht ra nhng in t. Nhng in t ny c tng tc qua mt in trng c in th khong 70eV trc khi i vo bung cha mu. p sut trong bung ion ha t 0,005torr, nhit 200 250C. Mnh M+.c khi lng nh molecular weight Electron Ionization (EI) 26. Cc in t va chm vi cc phn t trung ha to ra nhng mnh ion, gc t do hay phn t trung ha nh. Sau cc ion i qua mt in trng 400-4000V tng tc, vn tc ion t l vi khi lng ca chng y l mt phng php rt ph bin dng nhiu trong GC-MS. Qu trnh to ra nhiu mnh rt hu hiu khi xc nh cu trc cht Electron Ionization (EI) 27. Electron Ionization (EI) 28. nh hng ca nng lng ion ha Electron Ionization (EI) 29. Electron Ionization (EI) 30. Qu trnh ion ha theo EI Electron Ionization (EI) 31. Qu trnh ion ha pentobarbital Electron Ionization (EI) 32. u im : Cho bit khi lng phn t ca cc mu phn tch, cu trc ha hc ca ca phn t mu thng qua thng tin cung cp bi cc mnh. Nhc im : Khng o dng cho nhng cht khng bn nhit hoc khng bay hi, khng phn bit c cc ng phn. Electron Ionization (EI) 33. Khi qut v ion ha ha hc + Ion ha ha hc l k thut to ra ion dng trong phn tch quang ph khi lng. + Trong k thut CI ngoi mu v kh mang, cn mt lng ln kh th a vo bung ion ha. Lng kh th rt ln so vi mu hu nh cc in t pht ra t dy tc u va chm vo kh th to ion kh th. + Cc ion kh th va chm, phn ng vi cc phn t mu to ra cc ion mu. + Nng lng ion ha trong CI l rt nh so vi EI nn s phn mnh to ra l t. Xc sut hnh thnh cc ion m l ln nn thng dng xc nh trng lng phn t. + C hai c ch hnh thnh ion l ion ha ha hc dng v ion ha ha hc m. Chemical Ionization (CI) 34. Chemical Ionization (CI) Tin trnh c bt u vi thuc th th kh nh methane, isobutane, or ammonia nhng cht ny b ion ha bi dng in t mang nng lng cao to ra nhng ion dng khc nhau. Tip theo dng ion ny va chm vo cc phn t kh cn xc nh to ra nhng mnh ion. u im : Dng CI khi phng php EI khng cho thy mi ion phn t Nhc im: Khng p dng cho nhng hp cht khng bn nhit, hay khng bay hi 35. Ion ha ha hc dng K thut Ion ha hoa hc dng gm c 4 qu trnh c bn: + Chuyn proton (Proton transfer) + Tch Hydride ( Hydride abstraction) + Cng thm (addition) + Trao i in tch (Charge exchange) K thut ion ha ha hc 36. Chuyn proton ha S chuyn proton c th biu din nh sau: BH+ + M MH+ +B + Kh th B i qua qu trnh ion ha bng proton ha. Trong trng hp ny i lc proton ca cht cn phn tch ln hn i lc proton ca kh th nn H+ di chuyn t BH+ sang MH+ to ra ion phn tch dng + Trng hp ny thng thy CH5 + , C2H5 + chuyn H+ qua cht cn phn tch to ra [M-H]+ + i lc ca kh th l vn chnh trong hnh thnh cation cht xc nh. Kh th CH4 c dng nhiu do i lc proton ca n thp K thut ion ha ha hc 37. Tch hydride Trong qu trnh ion kh th. Ion cht phn ng c to ra do s mt hydrua khi tng tc vi cc ion kh th. iu ny rt thng gp i vi nhng alkan mch di. V d khi kh th l CH4, qu trnh to ion kh th l CH5 + . S hnh thnh ion mu nh sau: CH5 + + M CH4+ H2 + [M-H]+ K thut ion ha ha hc 38. Cng hp cation vo phn t Vi nhiu hp cht ha hc s tch H+ hay H- khng u i v mt nhit ng hc qu trnh. Trong nhng trng hp ny kh th thng hot tnh cng hp vi cht phn tch to ra ion nh: [M-C3H7]+ , [M-C2H5]+ , [M-C3H5]+ ng vi cc mi pick ( M+43), ( M+ 29), (M+41) K thut ion ha ha hc 39. Ion ha trao i in tch S ion ha trao i in tch c th m t bng phn ng sau: Trong X+ l kh th c ion ha, M l cht phn tch . Khi cc kh th c s dng cho trao i in t l nhng kh tr nh He, Ne, Ar, CO2, N2, H2 v.v.. Khng c kh nng phn ng vi cht phn tch. K thut ion ha ha hc 40. Ion ha ha hc m (NCI) K thut NCI c thc hin bng b phn phn tch th phn cc i chiu chn ion. Trong k thut ny, kh th thng c xem l kh m v kh b bn ph in t t dy tc nng lng cao s xy ra phn ng : V d nh kh th l CH4 ta c phn ng nh sau: in t nhit l in t pht ra t kh th nn c nng lng thp hn. Chnh nhng enhit l nhng in t phn ng vi vi cc phn t mu K thut ion ha ha hc 41. C ch hnh thnh NCI thng gm cc k thut sau : + Bt gi in t (Electrone capture) + Bt gi in t phn mnh.(Dissociative electrone capture) + Hnh thnh cp ion (ion pair formation) K thut ion ha ha hc 42. Ion ha bt gi in t K thut ion ha bt gi in t l k thut thng gp trong NCI. Trong nhng iu kin c th k thut ny c nhy cao hn PCI t 10- 1000 ln. Phn ng bt gi in t c th m t nh sau : Trong MX l phn t mu, enhit l in t sinh ra do tng tc gia cc in t nng lng v kh th. Trong nhiu trng hp ion MX+. khng bn c th xy ra phn ng nghch to MX tch mt in t. K thut ny thng xy ra nhng d t nh cc nguyn t thuc nhm hologen K thut ion ha ha hc 43. Bt gi in t phn mnh K thut bt gi in t phn mnh ging nh bt gi in t, im khc bit l trong k thut bt gi in t phn t mu b phn ly to mt gc t do v mt anion. C ch ca bt gi in t phn mnh c th minh ha nh sau: Cc ion v gc t do hnh thnh t qu trnh bt gi in t c th ti kt hp to thnh to thnh phn t ban u K thut ion ha ha hc 44. K thut hnh thnh cp ion C ch hnh thnh cp ion nhn chung ging vi c ch bt gi in t phn mnh, im khc bit l to ra cp ion dng v m. Phng trnh m t s phn mnh c th nh sau: + Mt im khc bit na l in t khng b bt gi nh hai trng hp trn m vn tn ti sau khi phn mnh. + Nguyn do ca s phn mnh l do s phn b khng u v mt in t lin kt K thut ion ha ha hc 45. Electrospray Ionization (ESI) Ph hp vi peptides, proteins, carbohydrates, small oligonucleotides, synthetic polymers, and lipids Electrospray ion ha l mt k thut ion ha mm thng c s dng xc nh khi lng phn t ca protein, peptide, v cc i phn t sinh hc khc. K thut ion ha mm l mt k thut hu ch khi p dng cc phn t sinh hc c khi lng phn t ln. Do khng c s phn mnh nn cc i phn t thnh cc ht tch in nh hn, thay v n bin phn t c ion ha thnh nhng git nh. Nhng git nh ny sau s to thm thnh nhng git nh hn, to ra cc phn t vi cc proton nh km. Cc ion phn t proton sau s c a qua my phn tch khi lng pht hin, v khi lng ca mu c th c xc nh 46. K thut eletrospray ionization Calculations for m/z in spectrum: [M+6H]6+ [M+5H]5+ [M+4H]4+ m/z = 15006/6 2501 m/z = 15005/5 =3001 m/z = 15004/4 = 3751[M + 3H]3+ [M + 2H]2+[M + H]1+ m/z = 15003/3 = 5001 m/z = 15002/2 = 7501 m/z = 15001/1= 15001 47. - Dung dch mu i vo vo phun ESI, ni t mt in th cao. - Vi phun ESI phun dung dch mu di dng sng to ra nhng git sng m tch in trn b mt. - S tch in gia tng khi dung mi ha hi t nhng git sng - Mt tch in b mt ca nhng ht sng gia tng lm cho tng tc tnh in tng s lm cho ht b v chia thnh nhng git sng mi nh hn. Tin trnh lp li nh trn c nh v to ra nhng ht sng rt nh. - T nhng git sng rt nh tch in cao to ra nhng ion mu chuyn vo th kh bng lc y tnh in - Nhng ion i vo khi ph v c phn tch K thut eletrospray ionization 48. Phn tch Phtt trong ph khi lng 70,000 Da L phng php ion ha mn nht c kh nng to ra nhng phc bng qu trnh cho nhn e trong pha kh. Rt thch hp trong sc kh kh Rt thch hp phn tch theo k thut MS2 nh by ion t cc, b ba C th phn tch nhng ion tch in ln hn 1 c khi lng ln. Khng b nh hng ca nn mu K thut eletrospray ionization u im 49. Nhc im K thut eletrospray ionization S hin din ca cc mui, cp ion ca thuc th nh TFA c th lm gim nhy. S to phc c th lm gim nhy Khng th phn tch nhiu thnh phn Nhng ion a ha tr rt d nhm ln nht l phn tch hn hp Cn tinh kit cao 50. Nanoelectrospray Ionization (NanoESI) u mi phun c thit k rt nh v n c t v tr rt gn vi ng dn ti thit b phn tch khi ph. S iu chnh hp l kh n gin ny thu c kt qu l lm tng hiu qu v lm gim lng mu o. Tng sensitive T l dng thp Kch c ht nh (~5) 51. u im Rt nhy T l dng thp p dng tt cho LC/MS C th p dng cho dch mui nng thp (low millimolar) p dng tt cho ion tch in a ha tr C th p dng cho hn hp Ion ha mm (little fragmentation observed). Nhc im T l dng thp i hi tnh nng cao ca thit b C th b hn ch khi phn tch hn hp Nanoelectrospray Ionization (NanoESI) 52. Trong APCI dng cht lng c a trc tip vo ngun ion ha. Tt c cc bc tip theo u xy ra y Cc ht lng di tc dng ca hi nng d dng ha hi phn ly. Cc phn t kh c gi y tip tc b ion ha p sut thng.. Atmospheric Pressure Chemical Ionization (APCI) 53. Atmospheric Pressure Chemical Ionization (APCI) 54. Atmospheric Pressure Chemical Ionization (APCI) 55. Atmospheric Pressure Chemical Ionization (APCI) Trong k thut ion ha APCI, cc ion c sinh ra v c phn tch nh sau: - Vi phun APCI phun dung dch mu thnh nhng git sng. - Nhng git sng c ha hi trong ng thp nhit cao. - Th c p vo kim t gn li ra ca ng thp. Th cao to ra s phng in vng trn hnh thnh nhng ion phn ng qua chui nhng phn ng ha hc vi nhng phn t dung mi v kh Nito bao quanh. - Nhng ion phn ng li phn ng li phn t mu hnh thnh nhng ion mu. - Nhng ion mu vo ph khi v c phn tch - Thng s dng trong LC-MS 56. u im Khi nhng ion dung mi hin din p sut thng, th s ion ha ha hc ca cc ion phn t phn tch c hiu qu cao. p sut thng cc ion phn t mu thng xuyn va chm vi ion ca thc th. Qu trnh dch chuyn proton hay phn ng proton ha d xy ra. Qu trnh cng in t hay kh proton to ([M-H]-) d hnh thnh. Nhng ion a ha tr khng tn ti do qu trnh ion ha c nng lng cao hn ESI Atmospheric Pressure Chemical Ionization (APCI) 57. So snh gia ESI v APCI 58. K thut thng xy ra vi HPLC. K thut ny dng phn tch cc hp cht khng phn cc. APPI ha hi mu bng tia ultra-violet . APPI c nhy cao hn ESI or APCI. Nhiu qu trnh ion ha i hi nng lng khong 10eV tng ng vi cc photon c bc sng t 83nm-153nm nm trong vng t ngoi chn khng do c th tin hnh bng va chm photon. Khi ph t c tng t nh EI. Do nng lng nh hn nn ph ny ch yu cho cc ion phn t v mt s mnh c s khi ln. Atmospheric pressure photoionization (APPI) 59. Atmospheric pressure photoionization (APPI) 60. Nhc im N c th to ra ion nn t dung mi. N i hi nhit cao (350- 500C) cho qu trnh ha hi iu ny dn n l nguyn nhn phn hy nhit. Atmospheric pressure photoionization (APPI) 61. Matrix-assisted laser desorption Ionization- MS (MALDI-MS) + Trong k thut ny ngi ta a t ngoi vo mt cht nn. Cht nn l nhng cht c phn t lng ln thng l nhng axit hu c yu. + Cht nn c trn u vi cht cn phn tch . + S chiu x hn hp gm cht nn v cht phn tch bng tia laser kt qu dn ti s bay hi ca cht nn mang theo c cht cn phn tch.Trong k thut ny cht nn ng mt vai tr rt quang trng. Cc phn t mu ha hi nhng khng trc tip hp thu nng lng laser. iu ny dn ti cc phn t khng b tia laser bin i.. 62. + Cht manh thng dng trong k thut ny l axit sinapinic hay gentisic. + Hn hp ny hp thu mnh bc sng laser 355nm. Khi chiu tia laser ln, do hn hp hp thu nng lng ln, cht phn tch c gii hp ra khi cht mang v ri c s trao i proton gia cht mang b quang hot vi cht cn kho st dn ti to ra ion cht cn kho st. Matrix-assisted laser desorption Ionization- MS (MALDI-MS) 63. Matrix-assisted laser desorption Ionization- MS (MALDI-MS) 64. u im : Phm vi nh lng ln ti 300,000 Da. Nhng mnh c khi lng ln hn cng c cc detector mi y pht hin. Ion ha mm vi s phn mnh t C th chp nhn mui nng nh millimolar Ph hp cho phn tch hp cht phc tp. Nhc im Cht nn c th nh hng cho nhng hp cht c khi lng di 700 Da. nhiu ca ng nn ohu5 thuc nhiu vo vt liu nn Matrix-assisted laser desorption Ionization- MS (MALDI-MS) 65. Field desorption ionization (FDI) + S dng in trng mnh lm bt ra cc in t t phn t. Vi b mt kim loi anot c hnh nhn hay si mng v di chn khng (10-6 torr) s pht sinh lc tnh in lm bt e ra khi phn t m khng i hi nng lng qu d. + Trong phng php ion ha in trng gii hp, ngun ion c to ra nh mt kim nh c d = vi m lm anod gn ngay trc khe bung ion ha, khe vo chnh l catod, cn khe hi t tp trung ngun ion 66. Thermal ionization Ion ha nhit c bn l da trn s hnh thnh cc ion nguyn t hay ion phn t trn b mt dy tc c t nng. Mu l c gi b mt ca dy tc ( thng dy tc lm bng (Re hay Ta), sau c sy kh t t. Dy tc c gia nhit chm mu dn ti qu trnh bay hi v ha hi mu. K thut c dng nhiu cho xc nh cc cu t nhit bay hi thp nhng nhit ion ha cao nh Ca. Thermal ionization p dng tt cho nhng php o cn ng v chnh xc khi xc nh t l ng v. N cng dng xc nh cc hm lng vt c t nguyn t c trong thc phm. 67. Accuracy Khong khi lng m my phn tch khi ph c th c c. phn gii ca mt php o l mc phn bit khi lng ca cc ion m my phn tch khi ph c th c c. ng ca mt php o l gi tr tm thy gn st vi gi tr thc nh th no.. ng ca mt php o l ph nhiu vo phng php phn tch, k thut phn tch v phn gii. Mass Range Resolution Scan Speed Mass Analyzer Properties of mass Analyzer L vng chu k thi gian cc ion c qut thng xuyn t thp n cao m / z hoc ngc li. 68. Mass Analyzer T cc (Quadrupole) T cc by ion (Quadrupole Ion Trap) By ion tuyt tnh (Linear Ion Trap) Cp i khu vc t trng (Double- Focusing Magnetic Sector) T cc thi gian bay song song MS (Quadrupole Time-of-Flight Tandem MS) T cc thi gian bay MS (Quadrupole Time-of-Flight MS) 69. Quadrupoles+ Mt b lc khi t cc bao gm bn thanh kim loi song song sp xp nh trong hnh bn. Hai thanh i din c in th dng ng vi +(U + V.cos (wt)) v hai thanh khc c tim nng - (U + V.cos (wt)), trong U l mt in th mt chiu v V.cos (wt) l mt in th xoay chiu. + in th t vo nh hng n qu o bay ca cc ion trong khng gian trung tm gia bn thanh. T cc (Quadrupole) 70. + ng vi mt th DC v AC cho trc , ch c cc ion c t l m/z tng thch mi c th bay, di chuyn n detector v c nhn bit. Cc ion khc b nm ra khi qu o ban u ca chng. T cc (Quadrupole) 71. + Quang ph khi lng thu c bng cch thay i th ca U v V hoc gi U v V nhng li thay i W. Nh vy cc ion mang t l m/z khc nhau s ln lt n detector v c ghi nhn T cc (Quadrupole) 72. phn gii ph k t cc thng thng t t 500- 1000, mun nng cao phn gii Rs c th ni 2-3 t cc vi nhau lc c th t 20.000 73. Quadrupole Ion Trap Thay i in th v tn s ca in cc vng s ln lt qut cc ion ra khi by n detector ghi nhn thnh ph. Thay i th ca hai in cc chm s gi c mt hay vi ion trong by nht nh. ., Ci by ion t cc thng bao gm mt in cc vng v hai in cc chm. Cc ion khi i vo by s b gi li bi in trng nu th ca in cc vng v ic cc chm khng khc nhau. Bng cch thay i in th ca cc ic cc ngi ta s iu kin c qu o ca cc ion trong by. 74. Cc phn t sau khi i ra khi ct sc k kh c ion ha trong hoc ngoi by ion ty theo kt cu my thit k cho s ion ha trong by hay c ion ngoi by. Cc ion sau c gi trong by bi mt hiu in th, vi c ch thay i hiu in th cc ion s ln lt thot ra ngoi n detector to ra tn hiu. Quadrupole Ion Trap 75. Thit b khi ph hi t n Single-Focusing Magnetic Sector 76. + Dng thit b t trng hnh qut tch cc ion theo khi lng. + Cc ion trc khi ra khi bung ion ha c tng tc nh mt in trng c th l U, i qua nam chm hnh ng c t trng H. Cc ion s chuyn ng theo hnh vng cung c bn r trong t trng ny vi + Vy vi gi tr U v H nht nh th th s khi m/z t l vi bn knh. Biu thc cho thy vi nhng ht c m/z khc nhau s s c tch ra khi nhau do r ca vng cung chuyn ng ca chng khc nhau. My hi tu n c phn gii thp t 1000-5000 77. My c phn gii t 10.000 ti 100.000. Ngi ta ch to b tch ion gm mt in trng v mt t trng t cnh nhau. Cc ion trc khi i qua t trng qut s i qua in trng tnh in tch bit nhau mt ln na Thit b khi ph hi t kp Double- Focusing Magnetic Sector 78. i vi b phn tch in trng v t trng cp i nh hng cc ion. Ch cho php cc ion c cng m/z v c cng ng nng vo u d, do vy mi khi ph rt hp, phn gii cao. Nh cc my phn gii km khng th phn bit c CO+, C2H4 +, N2 + nhng vi my c phn gii cao c th d dng phn bit c CO+( 29,9949), N2 +(28,0062), C2H4 +(28,0312) Thit b khi ph hi t kp Double- Focusing Magnetic Sector 79. Thit b khi ph hi t kp Double- Focusing Magnetic Sector 80. Phn tch thi gian bay da trn s tng tc mt nhm cc ion i n detector. Cc ion ny u nhn mt nng lng nh nhau thng qua s gia tng in th. V cc ion u c mt nng lng tng t nhau nhng mang mt khi lng khc nhau nn chng tin n detector nhng thi im khc nhau, Nhng ion nh s n trc v vn tc ca chng ln hn. Nhng ion nng n sau do vn tc ca chng thp hn. V vy k thut phn tch c gi l time-of-flight v khi lng c xc nh thng qua thi gian ca ion tin n detector B phn tch Time-of-Flight 81. B phn tch Time-of-Flight + TOF MS rt t trng trong lnh vc sinh hc. + nhy rt cao hu nh c th o c cc ion + Khong o l gn nh khng gii hn S ci thin Reflector thay v linear c th ko di khong ng i do c th lm tng phn gii hn. 82. Quadrupole Time-of-Flight MS B phn phn tch T cc thi gian bay l mt loi thng cp i vi ngun ion ha bn in t v mi y ngi ta thnh cng khi kt hp vi k thut ion ha MALDI. K thut ny c nhy, ng v hiu qu cao hn, tt hn khi so snh vi Quadrupole and TOF analyzer. 83. Photomultiplier Conversion Dynode Faraday Cup Array Detector Charge (or Inductive) Detector Electron Multiplier Detectors used in mass spectrometer 84. Faraday Cup + Khi mt ion p vo b mt ca dynode ca Faraday cup (BeO, GaP, or CsSb) chng s bc cc electron ra khi b mt tin ti ni c th thu nhn electron. + S bc cc ecectron ra khi b mt lm cho b mt tch in dng ( b mt detector) to iu kin cho dng in hnh thnh. + Cng dng in hnh thnh trong mch l c s d nh lng lng ion ban u... + Khng c bit nhy cm + Kh nng khuch i hn ch v tn hiu + Chu c p lc tng i cao. 85. Photomultiplier Conversion Dynode Cc in t th cp p vo mng phospho ca photomultiplier thay v p vo dynode. Cc photon c tng theo cp s nhn khi dp vo nhng b mt tip theo trong photomultiplier.Lng photon ny c chuyn ha bng dng in t nh c ch t bo quang in. Dng in o c cho php nh lng lng ion ban u. 86. Mass spectrometer Electron Multiplier y l mt detector rt quang trng c dng rng ri. C khong t 12 24 dynod c lm bng Al2O3 C th lm tng tn hiu p dng khi xc nh hm lng vt Cc ion khi p vo b mt dynode u tin x bc cc in t ra khi b mt. Nhng in t ny tip tc p vo b mt nhng dynod tip theo lm tng dng electron v nh vp to ra dng in ln 87. Mass spectrometer Vacuum in the Mass Spectrometer Tt c cc thit b khi ph cn c chn khng. Khng gian chn khng s cho php tt c cc ion tin ti detector m khng va chm vo cc phn t hay nguyn t kh khc. Nu qu trnh va chm xy ra th th thit b s b nh hng do s gim phn gii ( resolution) v nhy ( sensitivity) 88. Mass spectrometer Phn tch cu trc v nhng phn mnh Molecular ion (Parent ion) Fragmentation peaks Base peak Isotopic peaks . Mass spectrum Biu biu th cng cc theo trc Y v phn mnh cc ion theo m/z trn trc X 89. Mass spectrometer Ion phn t (Parent ion) L pick c xem nh l khi lng ca cht xc nh c hnh thnh t phn t ban u do qu trnh ion ha t s mt mt in t hay cng hp mt in t to thnh cation hay anion. N c t tn l s parent peak, radical peak. 90. Peaks mnh + L nhng pick hin din do s phn mnh ca hp cht. + Cc ion m mang mt nng lng khng bn vng, v mt phn trong chng s b v to ra nhng mnh nh hn. Trng hp n gin l ion m b tch thnh 2 mnh Mt ion dng v mt gc t do. + Gc t do s khng hnh thnh mt pick trn ph . Ch c nhng ht tch in mi c tng tc, i qua t trng v c xc nh bi b phn phn tch khi ph. Nhng ht khng tch in b loi ra khi thit b bng t bm chn khng 91. Peak nn Pick c cng ln nht trong ph l pick nn. N c th l pick m hoc khng phi pick m. Pick nn khng phi lc no cng l pick m v pick m khng phi lc no cng l pick nn. 92. Nhng mu phn mnh Lm vic trn nhng mu phn mnh ta c th d dng nghin cu cu trc ca hp cht. Quy tc Stevenson Homolytic bond cleavage Heterolytic fragmentation Alpha - cleavage Beta-cleavage Inductive cleavage Retro Diels-Alder Cleavage McLafferty rearrangement Ortho effect Onimum Reaction CO Elimination 93. Stevensons Rule Qu trnh phn mnh hu nh l to ra nhng mnh ion dng vi nng lng ion ha thp Ni cch khc l qu trnh phn mnh s u tin to thnh nhng ion c bn cao hn l nhng ion khng bn.. Cc lin kt b t dn ti hnh thnh nhng cacboncation. Nhng cacboncation c b cao s c xc sut hnh thnh ln nht. Nh vy nhng ankyl c R ln ph hp vi cu hnh khng gian s c xc sut to nhiu. 94. Homolytic bond cleavage Loi phn mnh ion trong mt lin kt b t do s chuyn mt e t lin kt n nguyn t mang in, cn mt in t khc thuc v nguyn t ban u ca n.Qu trnh dch chuyn in t c biu th bng mi tn cong. Hnh bn biu th s phn mnh ca mt ceton.. 95. Heterolytic bond cleavage Loi phn mnh ion trong lin kt b t do s chuyn c mt cp ion ca lin kt n nguyn t tch in. Qu trnh dch chuyn ca c mt cp in t c biu th bng mi tn 96. Alpha cleavage Kiu t ny thng xy ra trong ru, ete bo, ete thm, hp cht vng thm v xeton v.v.. S t xy ra lin kt cacbon Alpha tip gip vi cc nguyn t khc (N, O, S). Qu trnh c hnh thnh cc nguyn t ny. Qu trnh xy ra ch to ra mt phn mnh (cation to ra l d dng phn mnh tip theo) 97. Alpha cleavage 98. S phn tch xy ra v tr lin kt th 2 so vi nguyn t l hay nhm chc no . Qu trnh to ra mt ion v mt gc t do. c gi l s t . Beta-cleavage 99. Beta-cleavage 100. Inductive cleavage t lin kt do nh hng ca hiu ng cm ng l hin tng mt cp in t dch chuyn v pha mt trung tm tch in dng. Qu trnh dch chuyn c ghi nhn bng mi tn. Qu trnh thng xy ra nhm chc ete 101. Retro Diels-Alder Cleavage Phn ng cng ng vng Diels - Alder l mt phn ng peri ha xy ra gia mt dien (4 electron pi) v mt dienophin (2 electron pi) to ra sn phm l vng xiclohexen. Phn ng Diels-Alder xy ra mt cch d dng nhit phng (hoc khi un nng nh). Mt v d n gin l phn ng gia butadien v dietylmaleat (cis) v dietyl fumarat (trans) c dn ra bn y: 102. Retro Diels-Alder Cleavage S t t lin kt hnh thnh c ngun gc ca phn ng Diels- Alder to ra mt cation c ngun gc l alken v mt dien ban u hay mt cation c ngun gc l dien ban u v mt alken. S t nay xy ra l ty thuc vo nhm th xung quanh m to ra loi cation no chim u th . 103. V d 104. McLafferty rearrangement Chuyn v ni phn t McLafferty to ra mt phn mnh c trng ca ion phn t ca mt hp cht cacbonyl c t nht mt hydro gamma. Kiu phn mnh ny to ra mt alken v mt cation gc t do. y l kiu phn mnh thng gp Carbonyl, carbocylic 105. Ortho effect S tng tc gia cc nhm th v tr ortho, c tc ng ngc vi v tr para v meta, ln h thng vng benzen lm cho s phn mnh xy ra theo con ng khc to nhng ion khc. iu ny cho php s phn bit gia cc loi ng phn. Biu cho thy mt trng hp trong ch c ng phn ortho c th tri qua vic sp xp li. 106. S phn mnh khc bit v tr O so vi M v P 107. C ch phn mnh 108. Onium Reaction The onium reaction xy ra do s t lin kt to ra cation v phn t trung ha Onium Ion: L nhng ion phi kim loi trn b mt ca chng c hn 8 e nh methonium ion CH5 + , oxonium, phosphonium, nitronium tetramethylammonium, (CH3)4N+ tetraethylammonium, (C2H5)4N+ tetrapropylammonium, (C3H7)4N+. 109. t nhm CO Nu c nhiu nhm carbonyl cng tn ti trong cng mt hp cht th s phn mnh c th xy ra tt c cc lin kt ny. S phn mnh xy ra cc hp cht nh aldehyde, ketones and phenols v,v,, Nhng hp cht vng khng no cha nhm carbonyl v cc ion carbonyl d b phn mnh ti lin kt ny 110. Rules for interpretation of mass spectrum DBR Calculations Nitrogen Rule Isotopic effect 111. Double bond or ring calculations tell us about how many rings or double bonds are present in a compound. DBR= C-H/2+N/2+1 C= number of carbon atoms H= number of hydrogen atoms N= number of nitogen atoms DBR Calculations 112. Nitrogen Rule Nu mt hp cht c cha mt s chn cc nguyn t nit (hoc khng c cc nguyn t nit), ion phn t ca n c khi lng l s chn. Tuy nhin, nu mt hp cht c cha mt s l ca cc nguyn t nit, ion phn t ca n s c gi tr khi lng l. Quy tc ny l rt hu ch xc nh hm lng nit ca mt hp cht cha bit . 113. Isotopic effect 114. LOGO L Nht Tm