Post on 11-May-2015
description
http://lawrencekok.blogspot.com
Prepared by Lawrence Kok
Tutorial on Mass Spectrometry, Isotopes Identification and Option A for SL/HL.
Relative Atomic Mass Isotopes are present
Weighted average mass- due to presence of isotopes
Relative Isotopic Mass, (Ar) of an element:•Relative isotopic mass = Average mass of one atom of element
1/12 x mass of one carbon-12• Relative isotopic mass, carbon = 12.01
RAM = 12.01Relative Abundance 98.9% 1.07%
13
Why RAM is not a whole number?
Relative Isotopic Mass:= (Mass 12C x % Abundance) + (Mass 13C x % Abundance) = (12 x 98.9/100) + (13 x 1.07/100) = 12.01
12
http://www.tutorvista.com/content/science/science-i/atoms-molecules/atom.php
Relative Atomic Mass Isotopes are present
Weighted average mass- due to presence of isotopes
Relative Isotopic Mass, (Ar) of an element:•Relative isotopic mass = Average mass of one atom of element
1/12 x mass of one carbon-12• Relative isotopic mass, carbon = 12.01
Video on Isotopes
RAM = 12.01Relative Abundance 98.9% 1.07%
13
Why RAM is not a whole number?
Relative Isotopic Mass:= (Mass 12C x % Abundance) + (Mass 13C x % Abundance) = (12 x 98.9/100) + (13 x 1.07/100) = 12.01
Video on weighted average Weighted average calculation
Video on Isotopes
RAM calculation
12
Mg - 3 Isotopes
24 Mg – (100/127.2) x 100% - 78.6%25 Mg – (12.8/127.2) x 100% - 10.0%26 Mg – (14.4/127.2) x 100% - 11.3%
Relative Isotopic Mass:= (Mass 24Mg x % Abundance) + (Mass 25Mg x % Abundance) + (Mass 26Mg x % Abundance)= (24 x 78.6/100) + (25 x 10.0/100) + (26 x 11.3/100) = 24.30
Relative Abundance % Abundance
Convert relative abundance to % abundance
Relative Isotopic Mass
Mg - 3 Isotopes
24 Mg – (100/127.2) x 100% - 78.6%25 Mg – (12.8/127.2) x 100% - 10.0%26 Mg – (14.4/127.2) x 100% - 11.3%
Relative Isotopic Mass:= (Mass 24Mg x % Abundance) + (Mass 25Mg x % Abundance) + (Mass 26Mg x % Abundance)= (24 x 78.6/100) + (25 x 10.0/100) + (26 x 11.3/100) = 24.30
Relative Abundance % Abundance
Pb - 4 Isotopes
204Pb – (0.2/10) x 100% - 2%206Pb – (2.4/10) x 100% - 24%207Pb – (2.2/10) x 100% - 22%208Pb – (5.2/10) x 100% - 52% Relative Isotopic Mass
= (Mass 204Pb x % Abundance) + (Mass 206Pb x % Abundance) + (Mass 207Pb x % Abundance) + (Mass 208Pb x % Abundance)= (204 x 2/100) + (206 x 24/100) + (207 x 22/100) + (208 x 52/100) = 207.20
Convert relative abundance to % abundance
Convert relative abundance to % abundance
Relative Abundance % Abundance
Relative Isotopic Mass
Isotopes
Stable Isotopes Unstable Isotopes
Unstable Isotopes – emits radiation
RADIOISOTOPES
Emit radiation form unstable isotope
Radioactive isotopes
Half-life
Uranium 238 4.5 x 109
Carbon-14 5.7 x 103
Radium-226 1.6 x 103
Strontium-90 28 years
Iodine-131 8.1 days
Bismuth-214 19.7 minutes
Polonium-214 1.5 x 10-4
Isotopes
Stable Isotopes Unstable Isotopes
Unstable Isotopes – emits radiation
RADIOISOTOPES
Radioisotopes •Half-life – time taken for conc/amt isotope to fall to half of its original value. •Half life decay – always constant
Shorter half-life More unstable, decay fast
Long half-life More stable, decay slowly
www.sciencelearn.org.nz
Emit radiation form unstable isotope
Half-life
Radioactive isotopes
Half-life
Uranium 238 4.5 x 109
Carbon-14 5.7 x 103
Radium-226 1.6 x 103
Strontium-90 28 years
Iodine-131 8.1 days
Bismuth-214 19.7 minutes
Polonium-214 1.5 x 10-4
Isotopes
Stable Isotopes Unstable Isotopes
Unstable Isotopes – emits radiation
RADIOISOTOPES
Simulation isotope 12C, 13C, 14C
Radioisotopes •Half-life – time taken for conc/amt isotope to fall to half of its original value. •Half life decay – always constant
Shorter half-life More unstable, decay fast
Long half-life More stable, decay slowly
www.sciencelearn.org.nz
Emit radiation form unstable isotope
Simulation isotope 1H, 2H, 3H
Video on Half life
Simulation half life C-14/uranuim
Half-life
Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
Carbon -14
Abundance – trace amt (Unstable , radioactive)
How is form?• C-14 produce in stratosphere when….. neutron hit a nitrogen atom to form C-14•C-14 to N-14 by converting neutron proton (proton stay in nucleus), electron emit as β radiation • emit as β ray.
(proton in nucleus – increase proton number)
emit as β ray.
•Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant)•Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
Carbon -14
Abundance – trace amt (Unstable , radioactive)
How is form?• C-14 produce in stratosphere when….. neutron hit a nitrogen atom to form C-14•C-14 to N-14 by converting neutron proton (proton stay in nucleus), electron emit as β radiation • emit as β ray.
(proton in nucleus – increase proton number)
emit as β ray.
•Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant)•Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
Simulation C-14 (Half life)At 100% (Starting)
Simulation C-14 (Half life)At 50% (Starting)
Click to view simulation
How Radiocarbon dating works?
Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
Carbon -14
Abundance – trace amt (Unstable , radioactive)
How is form?• C-14 produce in stratosphere when….. neutron hit a nitrogen atom to form C-14•C-14 to N-14 by converting neutron proton (proton stay in nucleus), electron emit as β radiation • emit as β ray.
(proton in nucleus – increase proton number)
emit as β ray.
•Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant)•Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
Video on C-14 Carbon Dating Video on C-14 Carbon Dating/Fossil Video on C-14 Half life Carbon Dating
Simulation C-14 (Half life)At 100% (Starting)
Simulation C-14 (Half life)At 50% (Starting)
Video on Radiocarbon dating
Click to view simulation
How Radiocarbon dating works?
Carbon – 3 Isotopes Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
Carbon -12 Carbon -14Carbon -13
Abundance – 99% (Stable) Abundance – 1% (Stable) Abundance – trace amt (Unstable , radioactive)
Carbon – 3 Isotopes Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
ConclusionRatio C14/C12 is constant is organism alive
Ratio C14/C12 drop organism die
Uses•Age dead organic material/fossil contain Carbon element•Max age limit is 60,000 years old.
Carbon -12 Carbon -14Carbon -13
Abundance – 99% (Stable) Abundance – 1% (Stable) Abundance – trace amt (Unstable , radioactive)
How is form?• C-14 produce in stratosphere when….. neutron hit a nitrogen atom to form C-14•C-14 to N-14 by converting neutron proton (proton stay in nucleus), electron emit as β radiation • emit as β ray.
(proton in nucleus – increase proton number)
emit as β ray.
•Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant)•Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
Carbon – 3 Isotopes Radiocarbon/carbon dating
• Half life C-14 = 5730 years• Beta (β/electron ) decay
ConclusionRatio C14/C12 is constant is organism alive
Ratio C14/C12 drop organism die
Uses•Age dead organic material/fossil contain Carbon element•Max age limit is 60,000 years old.
Carbon -12 Carbon -14Carbon -13
Abundance – 99% (Stable) Abundance – 1% (Stable) Abundance – trace amt (Unstable , radioactive)
How is form?• C-14 produce in stratosphere when….. neutron hit a nitrogen atom to form C-14•C-14 to N-14 by converting neutron proton (proton stay in nucleus), electron emit as β radiation • emit as β ray.
(proton in nucleus – increase proton number)
emit as β ray.
•Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant)•Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
How it is form?
Mass Spectrometer
Uses mass spectrometer
Relative atomic mass of an element
Relative Molecular mass of a molecule
CO2
Mass Spectrometer
Uses mass spectrometer
Presence of isotopes and its abundance
Relative atomic mass of an element
Relative Molecular mass of a molecule
CO2
Mass Spectrometer
Uses mass spectrometer
Presence of isotopes and its abundance
Relative atomic mass of an element
Relative Molecular mass of a molecule
Structure of organic compound
Distinguish between structural isomers
CH3CH2CH2OH OH |CH3CHCH3
CH3 |CH3C-CH3
| CH3
CO2
structural formula
Organic structure determination
Mass Spectrometer
Parts of Mass Spectrometer
Sample injection
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
Mass Spectrometer
Parts of Mass Spectrometer
Sample injection
Vaporization Chamber • Sample heat to vapour state
Ionization Chamber • Molecule bombard with electrons form positive ions
Accelerator Chamber• M+ ions accelerated by Electric field
Deflector • M+ ions deflected by magnetic field
Detector • Convert abundance of M+
ions to electrical current.• M+ ions neutralize by electrons (more e needed - higher current – higher intensity of peak)• Intensity of peak show -relative abundance of ions
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
2
1
4
5
Mass Spectrometer
Parts of Mass Spectrometer
Sample injection
Vaporization Chamber • Sample heat to vapour state
Ionization Chamber • Molecule bombard with electrons form positive ions
Accelerator Chamber• M+ ions accelerated by Electric field
Deflector • M+ ions deflected by magnetic field
Detector • Convert abundance of M+
ions to electrical current.• M+ ions neutralize by electrons (more e needed - higher current – higher intensity of peak)• Intensity of peak show -relative abundance of ions
Sample X bombarded by electron • Form positive M+ ion• Accelerated (Electric Field)• Deflected (Magnetic Field) and Detected X + e- → X+ + 2e-
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
2
1
3 4
Click here notes from chemguide Detail notes from chem msu
5
Mass Spectrometer
Parts of Mass Spectrometer
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
Click here for simulation
Mass Spectrometer
Parts of Mass Spectrometer
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
Click here for simulation VaporizationInjection/ vaporization of sampleliquid state gaseous
Ionization•Form radical cations, M+
Acceleration• M+ ions accelerated by Electric field
Deflection• M+ ion deflected by magnetic field
2
3 4
15 Detector
• Convert abundance of M+ ions to electrical current.• M+ ion neutralize by electrons (more e needed - higher current – higher intensity of peak)• Intensity of peak show -relative abundance of ions
Mass Spectrometer
Parts of Mass Spectrometer
Vaporization
Ionization
Accelerator
Deflector
Detector
321 54
Click here for simulation VaporizationInjection/ vaporization of sampleliquid state gaseous
Ionization•Form radical cations, M+
Acceleration• M+ ions accelerated by Electric field
Deflection• M+ ion deflected by magnetic field
Deflection depend: •mass/charge (m/z) ratio: (m/z) ratio HIGH↑ - Deflection LOW↓
Deflection depend:• mass/charge (m/z) ratio: (m/z) ratio LOW↓- Deflection HIGH ↑
37CI+
35CI+
35CI2+
2
3 4
15 Detector
• Convert abundance of M+ ions to electrical current.• M+ ion neutralize by electrons (more e needed - higher current – higher intensity of peak)• Intensity of peak show -relative abundance of ions
Excellent Online Spectra Database. Click here to view
Mass Spectra Online Database
1 Search methane molecule, CH4
Mass/charge m/z
Relative abundance
Isotopic peak M+ + 1
Molecular ion peak, M+
2 Fragmentation pattern CH4
3 Mass Spectrum CH4
Excellent Online Spectra Database. Click here to view
Mass Spectra Online Database
1 Search methane molecule, CH4
Video on mass spectrometer
Mass/charge m/z
Relative abundance
Isotopic peak M+ + 1
Molecular ion peak, M+
2 Fragmentation pattern CH4
3 Mass Spectrum CH4
Video Ionization/fragmentation Video how MS works Video Mass spectrometer Video how MS works
Mg - 3 Isotopes
26 Mg - 11.3% - m/z highest – deflect LEAST25 Mg - 10.0% 24 Mg – 78.6% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (24Mg x % Ab) + (25Mg x % Ab) + (26Mg x % Ab)= (24 x 78.6/100) + (25 x 10.0/100) + (26 x 11.3/100) = 24.30
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOST Deflect LEAST
Mg - 3 Isotopes
26 Mg - 11.3% - m/z highest – deflect LEAST25 Mg - 10.0% 24 Mg – 78.6% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (24Mg x % Ab) + (25Mg x % Ab) + (26Mg x % Ab)= (24 x 78.6/100) + (25 x 10.0/100) + (26 x 11.3/100) = 24.30
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOST Deflect LEAST
Pb - 4 Isotopes
208Pb – 52% - m/z highest – deflect LEAST207Pb - 22% 206Pb - 24% 204Pb – 2% - m/z lowest – deflect MOST
Relative Isotopic Mass= (204Pb x % Ab) + (206Pb x % Ab) + (207Pb x % Ab) + (208Pb x % Ab)= (204 x 2/100) + (206 x 24/100) + (207 x 22/100) + (208 x 52/100) = 207.20
Deflect MOST Deflect LEAST
CI - 2 Isotopes
37 CI – 24.5% - m/z highest – deflect LEAST 35 CI – 75.5% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (35CI x % Ab) + (37CI x % Ab)= (35 x 75.5/100) + (37 x 24.5/100) = 35.5
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOSTDeflect LEAST
35CI 37CI
35CI 37CI
CI - 2 Isotopes
37 CI – 24.5% - m/z highest – deflect LEAST 35 CI – 75.5% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (35CI x % Ab) + (37CI x % Ab)= (35 x 75.5/100) + (37 x 24.5/100) = 35.5
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOSTDeflect LEAST
Br - 2 Isotopes
81Br – 49.3% - m/z highest – deflect LEAST79Br – 50.6% - m/z lowest – deflect MOST
Deflect MOSTDeflect LEAST
35CI 37CI
35CI 37CI
Relative Isotopic Mass:= (79Br x % Ab) + (81Br x % Ab)= (79 x 50.6/100) + (81 x 49.3/100) = 79.9
79Br 81Br
79Br 81Br
H - 3 Isotopes
3H – trace amt 2H – 0.015% - m/z highest – deflect LEAST 1H – 99.9% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (1H x % Ab) + (2H x % Ab)= (1 x 99.9/100) + (2 x 0.015/100) = 1.007
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOSTDeflect LEAST
1H 2H
1H 2H
3H
H - 3 Isotopes
3H – trace amt 2H – 0.015% - m/z highest – deflect LEAST 1H – 99.9% - m/z lowest – deflect MOST
Relative Isotopic Mass:= (1H x % Ab) + (2H x % Ab)= (1 x 99.9/100) + (2 x 0.015/100) = 1.007
Using Mass spectrometry to determine Relative Isotopic Mass
Deflect MOSTDeflect LEAST
C - 3 Isotopes
14C- trace amt13C – 1.1% - m/z highest – deflect LEAST12C – 98.9% - m/z lowest – deflect MOST
Deflect MOSTDeflect LEAST
1H 2H
1H 2H
Relative Isotopic Mass:= (12C x % Ab) + (813Cx % Ab)= (12 x 98.9/100) + (13 x 1.1/100) = 12.01
12C 13C
12C 13C
3H
14C
Ionization and Fragmentation Process- CH3CH2CH2CH3
Ionization Process - CH3CH2CH2CH3
• Bombarded by electron form cation• Molecular ion, M+ = 58• (CH3CH2CH2CH3)
+ = 58
H H | |CH3CH2CH2 C:H + e → CH3CH2CH2
C+.H + 2e | | H H
Ionization M+, m/z = 58
CH3CH2CH2CH3 + e → CH3CH2CH2CH3
+ + 2e
m/z = 58
Ionization forming M+
CH3CH2CH2 : CH3 + e → CH3CH2CH2+.CH3 + 2e
• Fragmentation of M+ producing 43CH3CH2CH2
+·CH3 → CH3CH2CH2+ + ·CH3
• Fragmentation of M+ producing 15CH3CH2CH2
+·CH3 → CH3CH2CH2· + +CH3
Ionization and Fragmentation Process- CH3CH2CH2CH3
Ionization Process - CH3CH2CH2CH3
• Bombarded by electron form cation• Molecular ion, M+ = 58• (CH3CH2CH2CH3)
+ = 58
Fragmentation Process CH3CH2CH2CH3 • Molecular ion, M+ undergo fragmentation • Cation and Radical form• Cation - Detected• Radical –Not detected (No charged)
H H | |CH3CH2CH2 C:H + e → CH3CH2CH2
C+.H + 2e | | H H
Ionization forming M+
CH3CH2:CH2CH3 + e → CH3CH2+·CH2CH3
+ 2e
• Fragmentation of M+ producing 29CH3CH2
+·CH2CH3 → CH3CH2+
+ .CH2CH3
Ionization M+, m/z = 58
CH3CH2CH2CH3 + e → CH3CH2CH2CH3
+ + 2e
Ionization and Fragmentation of M+
• Form - m/z = 58, 43 and 15
m/z = 58
m/z = 43
m/z = 15
Ionization and Fragmentation of M+
• Form- m/z = 58 and 29
m/z = 58
m/z = 58
m/z = 29
Ionization forming M+
CH3CH2CH2 : CH3 + e → CH3CH2CH2+.CH3 + 2e
• Fragmentation of M+ producing 43CH3CH2CH2
+·CH3 → CH3CH2CH2+ + ·CH3
• Fragmentation of M+ producing 15CH3CH2CH2
+·CH3 → CH3CH2CH2· + +CH3
Ionization and Fragmentation Process- CH3CH2CH2CH3
Ionization Process - CH3CH2CH2CH3
• Bombarded by electron form cation• Molecular ion, M+ = 58• (CH3CH2CH2CH3)
+ = 58
Fragmentation Process CH3CH2CH2CH3 • Molecular ion, M+ undergo fragmentation • Cation and Radical form• Cation - Detected• Radical –Not detected (No charged)
H H | |CH3CH2CH2 C:H + e → CH3CH2CH2
C+.H + 2e | | H H
Ionization forming M+
CH3CH2:CH2CH3 + e → CH3CH2+·CH2CH3
+ 2e
• Fragmentation of M+ producing 29CH3CH2
+·CH2CH3 → CH3CH2+
+ .CH2CH3
Ionization M+, m/z = 58
CH3CH2CH2CH3 + e → CH3CH2CH2CH3
+ + 2e
Ionization and Fragmentation of M+
• Form - m/z = 58, 43 and 15
m/z = 58
m/z = 43
m/z = 15
Ionization and Fragmentation of M+
• Form- m/z = 58 and 29
m/z = 58
m/z = 58
m/z = 29
Ionization and Fragmentation
Unpair electronPositively charged
Will MOVE (ACCELARATED) NOT move
CH3CH2CH2CH3
CH3CH2CH2CH3+- 58 - m/z highest –deflect
LEAST CH3CH2CH2
+ – 43 CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2CH3
Deflect MOST Deflect LEAST
CH3CH2CH2CH3+
CH3CH2CH2+
Fragmentation
ionization
CH3+
CH3+
CH3CH2+
CH3CH2CH2CH3
+
CH3CH2CH2CH3
CH3CH2CH2CH3+- 58 - m/z highest –deflect
LEAST CH3CH2CH2
+ – 43 CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2CH3
Deflect MOST Deflect LEAST
CH3CH2CH2CH3+
CH3CH2CH2+
Fragmentation
ionization
CH3+
CH3+
Ionization and Fragmentation Process
Fragmentation
Ionization of CH3CH2CH2CH3 CH3CH2CH2CH3 + e → CH3CH2CH2CH
3+ + 2e → 58
or CH3CH2:CH2CH3 + e → CH3CH2
+·CH2CH3 + 2e → 58
Mass spectrum CH3CH2CH2CH3 IonizationCH3CH2CH2CH3
CH3CH2+
CH3CH2CH2CH3
+
Fragmentation of M+
CH3CH2CH2+·CH3 → CH3CH2CH2
+ - 43
CH3CH2+·CH2CH3 → CH3CH2
+ – 29 CH3CH2CH2
+·CH3 → +CH3 - 15
CH3CH2CH2CH3+- 58 - m/z highest –deflect
LEAST CH3CH2CH2
+ – 43 CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
CH3CH2CH2OH
CH3CH2CH2OH+- 60 - m/z highest –deflect LEAST CH2CH2OH+ – 45CH2OH+ - 31CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH
Deflect MOST Deflect LEAST
CH3CH2CH2OH+
Fragmentation
ionization
CH3 +
CH3+
CH3CH2+
CH3CH2CH2OH+
CH2CH2OH+ CH2OH+
15 60
CH3CH2CH2OH
CH3CH2CH2OH+- 60 - m/z highest –deflect LEAST CH2CH2OH+ – 45CH2OH+ - 31CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH
Deflect MOST Deflect LEAST
CH3CH2CH2OH+
Fragmentation
ionization
CH3 +
CH3+
Ionization and Fragmentation Process
Fragmentation
Ionization of CH3CH2CH2OHCH3CH2CH2OH + e → CH3CH2CH2OH+ + 2e → 60 orCH3CH2CH2OH + e → CH3CH2
+. CH2OH + 2e → 60
Mass spectrum CH3CH2CH2CH3 IonizationCH3CH2CH2OH
CH3CH2+
CH3CH2CH2OH+
Fragmentation of M+
CH3+.CH2CH2OH→ +CH2CH2OH
- 45
CH3CH2+·CH2OH→ +CH2OH
– 31 CH3CH2
+·CH2OH→ CH3CH2+
– 29
CH3+.CH2CH2OH→ +CH3
- 15
CH2CH2OH+ CH2OH+
15 60
CH3CH2CH2OH+- 60 - m/z highest – deflect LEAST CH2CH2OH+ – 45CH2OH+ - 31CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
15 60
CH3CH(CH3)CH2CH3+- 72 - m/z highest –
deflect LEAST CH3CH(CH3)CH2
+ – 57CH3CH(CH3)+ - 43CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3
Deflect MOST Deflect LEAST
CH3CH(CH3)CH2CH3+
Fragmentation
Ionization
CH3+
CH3+
CH3CH(CH3)+
15
CH3CH(CH3)CH2+
CH3CH(CH3)CH2CH3+
CH3CH2+
CH3CH(CH3)CH2CH3+
CH3CH(CH3)CH2CH3+- 72 - m/z highest –
deflect LEAST CH3CH(CH3)CH2
+ – 57CH3CH(CH3)+ - 43CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3
Deflect MOST Deflect LEAST
CH3CH(CH3)CH2CH3+
Fragmentation
Ionization
CH3+
CH3+
Ionization and Fragmentation Process
Fragmentation
Ionization of CH3CH(CH3)CH2CH3 CH3CH(CH3)CH2CH3 + e → CH3CH(CH3)CH2CH3
+ + 2e → 72 orCH3CH(CH3)CH2CH3 + e → CH3CH(CH3)CH2
+.CH3+ 2e → 72 orCH3CH(CH3)CH2CH3 + e → CH3CH(CH3)+.CH2CH3 + 2e → 72
Mass spectrum CH3CH(CH3)CH2CH3 IonizationCH3CH(CH3)CH2CH3
Fragmentation of M+
CH3CH(CH3)CH2+ -
57CH3CH(CH3)+ – 43 CH3CH2
+
– 29CH3
+ - 15
CH3CH(CH3)+
15
CH3CH(CH3)CH2+
CH3CH(CH3)CH2CH3+
CH3CH2+
CH3CH(CH3)CH2CH3+
CH3CH(CH3)CH2CH3+- 72 - m/z highest –
deflect LEAST CH3CH(CH3)CH2
+ – 57CH3CH(CH3)+ - 43CH3CH2
+ – 29 CH3
+ –15 - m/z lowest– deflect MOST
(C(CH3)4)+ - 72 - m/z highest –
deflect LEAST (C(CH3)3)
+ – 57(C(CH3)2)
+ - 42(C(CH3))
+ – 27CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4
Deflect MOST Deflect LEAST
(C(CH3)4)+
Fragmentation
Ionization
CH3+
CH3+
(C(CH3)3)+
(C(CH3)4)
(C(CH3)2)+
(C(CH3))+
(C(CH3)4)+
(C(CH3)4)+ - 72 - m/z highest –
deflect LEAST (C(CH3)3)
+ – 57(C(CH3)2)
+ - 42(C(CH3))
+ – 27CH3
+ –15 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4
Deflect MOST Deflect LEAST
(C(CH3)4)+
Fragmentation
Ionization
CH3+
CH3+
Ionization and Fragmentation Process
Fragmentation
Ionization of C(CH3)4
C(CH3)4 + e → (C(CH3)4)+ + 2e
→ 72
Mass spectrum C(CH3)4 IonizationC(CH3)4
(C(CH3)3)+
(C(CH3)4)
(C(CH3)2)+
(C(CH3))+
(C(CH3)4)+ - 72 - m/z highest –
deflect LEAST (C(CH3)3)
+ – 57(C(CH3)2)
+ - 42(C(CH3))
+ – 27CH3
+ –15 - m/z lowest– deflect MOST
Fragmentation of M+
(C(CH3)3)+ – 57
(C(CH3)2)+ - 42
(C(CH3))+ – 27
CH3+ –15
(C(CH3)4)+
CI2molecule
37CI-37CI - 74 - m/z highest – deflect LEAST 35CI-37CI –72 35CI-35CI –70 37CI –37 35CI –35 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI2
Deflect MOST Deflect LEAST
35CI-35CI+
35CI+
35CI-37CI+
37CI-37CI+
Fragmentation
form atoms
Ionization
37CI+
35CI+
37CI-37CI+
CI2molecule
37CI-37CI - 74 - m/z highest – deflect LEAST 35CI-37CI –72 35CI-35CI –70 37CI –37 35CI –35 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI2
Deflect MOST Deflect LEAST
35CI-35CI+
35CI+
35CI-37CI+
37CI-37CI+
Fragmentation
form atoms
Ionization
37CI+
35CI+
37CI-37CI+
Ionization and Fragmentation Process
Fragmentation
Fragmentation of CI2+ into CI+
CI+.CI → [35CI+ + 35CI·] + 2e –35
CI+.CI → [37CI+ + 37CI·] + 2e –37
Ionization of CI2 to CI2+
CI:CI + e- →[35CI+.35CI] + 2e – 70CI:CI + e- →[35CI+.37CI] + 2e – 72CI:CI + e- →[37CI+.37CI] + 2e – 74
m/z = 37
m/z = 35
Ratio (35CI : 37CI) - 3:1
Mass spectrum CI2 / CI atoms
Ratio (35CI35CI: 35CI37CI: 37CI37CI) - 9:6:1
IonizationCI2 molecule
37CI-37CI - 74 - m/z highest – deflect LEAST 35CI-37CI –72 35CI-35CI –70 37CI –37 35CI –35 - m/z lowest– deflect MOST
Br2molecule
81Br-81Br - 162 - m/z highest – deflect LEAST 79Br-81Br –160 79Br-79Br –158 81Br –81 79Br –79 - m/z lowest– deflect MOST
Deflect MOST Deflect LEAST
79Br-79Br+
79Br+
79Br-81Br+
81Br-81Br+
Fragmentation
form atoms
Ionization
81Br+
79Br+
81Br-81Br+
Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br2
Br2molecule
81Br-81Br - 162 - m/z highest – deflect LEAST 79Br-81Br –160 79Br-79Br –158 81Br –81 79Br –79 - m/z lowest– deflect MOST
Deflect MOST Deflect LEAST
79Br-79Br+
79Br+
79Br-81Br+
81Br-81Br+
Fragmentation
form atoms
Ionization
81Br+
79Br+
81Br-81Br+
Ionization and Fragmentation Process
Fragmentation
Fragmentation of Br2+
to Br+
Br+.Br → [81Br+ + 81Br·] – 81
Br+.Br →[79Br+ + 79Br·] – 79
Ionization of Br2 to Br2
+
Br:Br + e- →[81Br+.81Br] + 2e – 162Br:Br + e- →[79Br+.81Br] + 2e – 160Br:Br + e- →[79Br+.79Br] + 2e– 158
m/z = 79
m/z = 81
Ratio (79Br : 81Br) - 1:1
Mass spectrum Br2 / Br atoms
Ratio (79Br79Br: 79Br81Br: 81Br81Br) – 1:2:1
IonizationBr2 molecule
81Br-81Br - 162 - m/z highest – deflect LEAST 79Br-81Br –160 79Br-79Br –158 81Br – 81 79Br – 79 - m/z lowest– deflect MOST
Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br2
Acknowledgements
Thanks to source of pictures and video used in this presentationhttp://serc.carleton.edu/research_education/geochemsheets/techniques/gassourcemassspec.htmlhttp://www.mhhe.com/physsci/chemistry/carey/student/olc/ch13ms.htmlhttp://science.howstuffworks.com/mass-spectrometry3.htm
Thanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com