Tutorial on Mass Spectrometry, Isotopes
Identification and Option A for SL/HL.

Prepared by
Lawrence Kok
http://lawrenceko...
Relative Atomic Mass

Isotopes are present

Why RAM is not a whole number?

12
Relative Abundance

98.9%

13
1.07%

RAM = ...
Relative Atomic Mass

Isotopes are present

Why RAM is not a whole number?

12
Relative Abundance

98.9%

13
1.07%

RAM = ...
Relative Isotopic Mass
Mg - 3 Isotopes

Relative Abundance

% Abundance
Convert relative abundance to % abundance

Mg – (1...
Relative Isotopic Mass
Mg - 3 Isotopes

Relative Abundance

% Abundance
Convert relative abundance to % abundance

Mg – (1...
Isotopes
Unstable Isotopes
Emit radiation form unstable isotope

Unstable Isotopes – emits radiation

RADIOISOTOPES

Stab...
Isotopes
Unstable Isotopes

Stable Isotopes

Emit radiation form unstable isotope

Unstable Isotopes – emits radiation

R...
Isotopes
Unstable Isotopes

Stable Isotopes

Simulation isotope 1H, 2H, 3H

Simulation isotope 12C, 13C, 14C

Emit radiati...
Radiocarbon/carbon dating
Carbon -14
Abundance – trace amt
(Unstable , radioactive)
• Half life C-14 = 5730 years
• Beta (...
How Radiocarbon dating works?

Radiocarbon/carbon dating
Carbon -14
Abundance – trace amt
(Unstable , radioactive)
• Half ...
How Radiocarbon dating works?

Radiocarbon/carbon dating
Carbon -14
Abundance – trace amt
(Unstable , radioactive)
• Half ...
Carbon – 3 Isotopes
Carbon -12
Abundance – 99% (Stable)

Carbon -13
Abundance – 1% (Stable)

Radiocarbon/carbon dating
Car...
Carbon – 3 Isotopes
Carbon -12
Abundance – 99% (Stable)

Carbon -13

Radiocarbon/carbon dating
Carbon -14

Abundance – 1% ...
Carbon – 3 Isotopes
Carbon -12

Carbon -13

Abundance – 99% (Stable)

Radiocarbon/carbon dating
Carbon -14

Abundance – 1%...
Mass Spectrometer
Uses mass spectrometer
Relative atomic mass
of an element

Relative Molecular mass
of a molecule

CO2
Mass Spectrometer
Uses mass spectrometer
Relative atomic mass
of an element

Relative Molecular mass
of a molecule

CO2

P...
Mass Spectrometer
Uses mass spectrometer
Relative atomic mass
of an element

Relative Molecular mass
of a molecule

Presen...
Mass Spectrometer
Parts of Mass Spectrometer
1

Vaporization

2

Ionization

Sample injection

3

Accelerator

4

Deflecto...
Mass Spectrometer
Parts of Mass Spectrometer
1

2

Vaporization

3

Ionization

Accelerator

4

5

Deflector

Detector

Sa...
Mass Spectrometer
Parts of Mass Spectrometer
1

2

Vaporization

3

Ionization

Accelerator

4

5

Deflector

Detector

Sa...
Mass Spectrometer
Parts of Mass Spectrometer
1

Vaporization

2

Ionization

3

Accelerator

Click here for simulation

4
...
Mass Spectrometer
Parts of Mass Spectrometer
1

1

Vaporization

2

3

Ionization

Vaporization
Injection/ vaporization of...
Mass Spectrometer
Parts of Mass Spectrometer
1

1

Vaporization

2

3

Ionization

Vaporization
Injection/ vaporization of...
Mass Spectra Online Database
Excellent Online Spectra Database. Click here to view

1

Search methane molecule, CH4

2

Fr...
Mass Spectra Online Database
Excellent Online Spectra Database. Click here to view

1

Search methane molecule, CH4

2

Fr...
Using Mass spectrometry to determine Relative Isotopic Mass
Mg - 3 Isotopes

Mg - 11.3% - m/z highest – deflect LEAST
Mg -...
Using Mass spectrometry to determine Relative Isotopic Mass
Mg - 3 Isotopes

Mg - 11.3% - m/z highest – deflect LEAST
Mg -...
Using Mass spectrometry to determine Relative Isotopic Mass
CI - 2 Isotopes

35

37
35

Relative Isotopic Mass:
= (35CI x ...
Using Mass spectrometry to determine Relative Isotopic Mass
CI - 2 Isotopes

35

37
35

Relative Isotopic Mass:
= (35CI x ...
Using Mass spectrometry to determine Relative Isotopic Mass
H - 3 Isotopes

H

1

2

H

H

3

H – trace amt
H – 0.015% - m...
Using Mass spectrometry to determine Relative Isotopic Mass
H - 3 Isotopes

H

1

2

H

H

3

H – trace amt
H – 0.015% - m...
Ionization and Fragmentation Process- CH3CH2CH2CH3

Ionization Process - CH3CH2CH2CH3

• Bombarded by electron form cation...
Ionization and Fragmentation Process- CH3CH2CH2CH3

Fragmentation Process CH3CH2CH2CH3
• Molecular ion, M+ undergo fragmen...
Ionization and Fragmentation Process- CH3CH2CH2CH3

Fragmentation Process CH3CH2CH2CH3
• Molecular ion, M+ undergo fragmen...
Mass spectrometry - Ionization/ Fragmentation pattern for CH 3CH2CH2CH3
CH3CH2CH2CH3

ionization
Fra
g

me
nta
tion

CH3CH...
Mass spectrometry - Ionization/ Fragmentation pattern for CH 3CH2CH2CH3
CH3CH2CH2CH3

ionization
Fra
g

me
nta
tion

CH3CH...
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH
CH3CH2CH2OH

Fra
g

ionization
me
nta

tion

CH3CH2C...
Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH
CH3CH2CH2OH

Fra
g

ionization
me
nta

tion

CH3CH2C...
Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3
Ionization

CH3CH(CH3)CH2CH3+
Fra
g

me
nta

tion

...
Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3
Ionization

CH3CH(CH3)CH2CH3+
Fra
g

me
nta

tion

...
Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4
(C(CH3)4)+

Ionization

(C(CH3)4)

Fragm
entatio

n

(C(CH3)...
Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4
(C(CH3)4)+

Ionization

(C(CH3)4)

Fragm
entatio

n

(C(CH3)...
Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI 2
CI2molecule

35

Ionization
Fra
gm
for enta
m a ti...
Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI 2
CI2molecule

35

Ionization
Fra
gm
for enta
m a ti...
Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br 2
Br2molecule

79

Ionization
Fra
gm
for enta
m a ti...
Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br 2
Br2molecule

79

Ionization
Fra
gm
for enta
m a ti...
Acknowledgements
Thanks to source of pictures and video used in this presentation
http://serc.carleton.edu/research_educat...
Upcoming SlideShare
Loading in...5
×

IB Chemistry on Mass Spectrometry and Isotopes for Option A SL/HL.

1,248

Published on

IB Chemistry on Mass Spectrometry and Isotopes for Option A SL/HL.

Published in: Education, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,248
On Slideshare
0
From Embeds
0
Number of Embeds
31
Actions
Shares
0
Downloads
58
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

IB Chemistry on Mass Spectrometry and Isotopes for Option A SL/HL.

  1. 1. Tutorial on Mass Spectrometry, Isotopes Identification and Option A for SL/HL. Prepared by Lawrence Kok http://lawrencekok.blogspot.com
  2. 2. Relative Atomic Mass Isotopes are present Why RAM is not a whole number? 12 Relative Abundance 98.9% 13 1.07% RAM = 12.01 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 Relative Isotopic Mass: = (Mass 12C x % Abundance) + (Mass 13C x % Abundance) = (12 x 98.9/100) + (13 x 1.07/100) = 12.01
  3. 3. Relative Atomic Mass Isotopes are present Why RAM is not a whole number? 12 Relative Abundance 98.9% 13 1.07% RAM = 12.01 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 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 Isotopes Video on weighted average Video on Isotopes http://www.tutorvista.com/content/science/science-i/atoms-molecules/atom.php RAM calculation Weighted average calculation
  4. 4. Relative Isotopic Mass Mg - 3 Isotopes Relative Abundance % Abundance Convert relative abundance to % abundance Mg – (100/127.2) x 100% - 78.6% Mg – (12.8/127.2) x 100% - 10.0% 26 Mg – (14.4/127.2) x 100% - 11.3% 24 25 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
  5. 5. Relative Isotopic Mass Mg - 3 Isotopes Relative Abundance % Abundance Convert relative abundance to % abundance Mg – (100/127.2) x 100% - 78.6% Mg – (12.8/127.2) x 100% - 10.0% 26 Mg – (14.4/127.2) x 100% - 11.3% 24 25 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 Pb - 4 Isotopes Relative Abundance % Abundance Convert relative abundance to % abundance Pb – (0.2/10) x 100% - 2% Pb – (2.4/10) x 100% - 24% 207 Pb – (2.2/10) x 100% - 22% 208 Pb – (5.2/10) x 100% - 52% 204 206 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
  6. 6. Isotopes Unstable Isotopes Emit radiation form unstable isotope Unstable Isotopes – emits radiation  RADIOISOTOPES Stable Isotopes
  7. 7. Isotopes Unstable Isotopes Stable Isotopes Emit radiation form unstable isotope Unstable Isotopes – emits radiation  RADIOISOTOPES Half-life Radioisotopes •Half-life – time taken for conc/amt isotope to fall to half of its original value. •Half life decay – always constant Radioactive isotopes 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 www.sciencelearn.org.nz Half-life 1.5 x 10-4 Long half-life More stable, decay slowly Shorter half-life More unstable, decay fast
  8. 8. Isotopes Unstable Isotopes Stable Isotopes Simulation isotope 1H, 2H, 3H Simulation isotope 12C, 13C, 14C Emit radiation form unstable isotope Simulation half life C-14/uranuim Unstable Isotopes – emits radiation  RADIOISOTOPES Half-life Radioisotopes •Half-life – time taken for conc/amt isotope to fall to half of its original value. •Half life decay – always constant Radioactive isotopes 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 www.sciencelearn.org.nz Half-life 1.5 x 10-4 Long half-life More stable, decay slowly Video on Half life Shorter half-life More unstable, decay fast
  9. 9. Radiocarbon/carbon dating Carbon -14 Abundance – trace amt (Unstable , radioactive) • Half life C-14 = 5730 years • Beta (β/electron ) decay 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 • number) emit as β ray. (proton in nucleus – increase proton 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)
  10. 10. How Radiocarbon dating works? Radiocarbon/carbon dating Carbon -14 Abundance – trace amt (Unstable , radioactive) • Half life C-14 = 5730 years • Beta (β/electron ) decay Simulation C-14 (Half life) At 100% (Starting) Simulation C-14 (Half life) At 50% (Starting) 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 • number) emit as β ray. (proton in nucleus – increase proton emit as β ray. Click to view simulation •Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant) •Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant)
  11. 11. How Radiocarbon dating works? Radiocarbon/carbon dating Carbon -14 Abundance – trace amt (Unstable , radioactive) • Half life C-14 = 5730 years • Beta (β/electron ) decay Simulation C-14 (Half life) At 100% (Starting) Simulation C-14 (Half life) At 50% (Starting) 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 • number) emit as β ray. (proton in nucleus – increase proton emit as β ray. Click to view simulation •Ratio C14/C12- constant if alive – TAKE in C14 (C12 constant) •Ratio C14/C12- drop if dead - NOT taking C14. (C12 constant) Video on Radiocarbon dating Video on C-14 Carbon Dating Video on C-14 Carbon Dating/Fossil Video on C-14 Half life Carbon Dating
  12. 12. Carbon – 3 Isotopes Carbon -12 Abundance – 99% (Stable) Carbon -13 Abundance – 1% (Stable) Radiocarbon/carbon dating Carbon -14 Abundance – trace amt (Unstable , radioactive) • Half life C-14 = 5730 years • Beta (β/electron ) decay
  13. 13. Carbon – 3 Isotopes Carbon -12 Abundance – 99% (Stable) Carbon -13 Radiocarbon/carbon dating Carbon -14 Abundance – 1% (Stable) Abundance – trace amt (Unstable , radioactive) • Half life C-14 = 5730 years • Beta (β/electron ) decay 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) Uses •Age dead organic material/fossil contain Carbon element •Max age limit is 60,000 years old. Conclusion Ratio C14/C12 is constant is organism alive Ratio C14/C12 drop  organism die
  14. 14. Carbon – 3 Isotopes Carbon -12 Carbon -13 Abundance – 99% (Stable) Radiocarbon/carbon dating Carbon -14 Abundance – 1% (Stable) Abundance – trace amt (Unstable , radioactive) How it is form? • Half life C-14 = 5730 years • Beta (β/electron ) decay 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) Uses •Age dead organic material/fossil contain Carbon element •Max age limit is 60,000 years old. Conclusion Ratio C14/C12 is constant is organism alive Ratio C14/C12 drop  organism die
  15. 15. Mass Spectrometer Uses mass spectrometer Relative atomic mass of an element Relative Molecular mass of a molecule CO2
  16. 16. Mass Spectrometer Uses mass spectrometer Relative atomic mass of an element Relative Molecular mass of a molecule CO2 Presence of isotopes and its abundance
  17. 17. Mass Spectrometer Uses mass spectrometer Relative atomic mass of an element Relative Molecular mass of a molecule Presence of isotopes and its abundance CO2 Organic structure determination Distinguish between structural isomers CH3CH2CH2OH Structure of organic compound OH | CH3CHCH3 CH3 | CH3C-CH3 | CH3 structural formula
  18. 18. Mass Spectrometer Parts of Mass Spectrometer 1 Vaporization 2 Ionization Sample injection 3 Accelerator 4 Deflector 5 Detector
  19. 19. Mass Spectrometer Parts of Mass Spectrometer 1 2 Vaporization 3 Ionization Accelerator 4 5 Deflector Detector Sample injection 5 Detector 1 • 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 Chamber • Sample heat to vapour state 2 Ionization Chamber • Molecule bombard with electrons form positive ions Accelerator Chamber • M+ ions accelerated by Electric field 4 Deflector • M+ ions deflected by magnetic field
  20. 20. Mass Spectrometer Parts of Mass Spectrometer 1 2 Vaporization 3 Ionization Accelerator 4 5 Deflector Detector Sample injection 5 Detector 1 • 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 Chamber • Sample heat to vapour state 2 Ionization Chamber • Molecule bombard with electrons form positive ions 3 Accelerator Chamber • M+ ions accelerated by Electric field 4 Deflector • M+ ions deflected by magnetic field Sample X bombarded by electron • Form positive M+ ion • Accelerated (Electric Field) • Deflected (Magnetic Field) and Detected X + e- → X+ + 2e- Click here notes from chemguide Detail notes from chem msu
  21. 21. Mass Spectrometer Parts of Mass Spectrometer 1 Vaporization 2 Ionization 3 Accelerator Click here for simulation 4 Deflector 5 Detector
  22. 22. Mass Spectrometer Parts of Mass Spectrometer 1 1 Vaporization 2 3 Ionization Vaporization Injection/ vaporization of sample liquid state  gaseous Click here for simulation 2 Ionization •Form radical cations, M+ 3 Acceleration • M+ ions accelerated by Electric field Accelerator 4 Deflection • M+ ion deflected by magnetic field 4 5 Deflector 5 Detector 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
  23. 23. Mass Spectrometer Parts of Mass Spectrometer 1 1 Vaporization 2 3 Ionization Vaporization Injection/ vaporization of sample liquid state  gaseous Accelerator Click here for simulation 4 5 Deflector 5 Detector 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 2 Ionization •Form radical cations, M+ Deflection depend: •mass/charge (m/z) ratio: (m/z) ratio HIGH↑ - Deflection LOW↓ 37 CI+ 35 CI+ CI2+ 35 3 Acceleration • M+ ions accelerated by Electric field 4 Deflection • M+ ion deflected by magnetic field Deflection depend: • mass/charge (m/z) ratio: (m/z) ratio LOW↓- Deflection HIGH ↑
  24. 24. Mass Spectra Online Database Excellent Online Spectra Database. Click here to view 1 Search methane molecule, CH4 2 Fragmentation pattern CH4 3 Mass Spectrum CH4 Mass/charge m/z Relative abundance Molecular ion peak, M+ Isotopic peak M+ + 1
  25. 25. Mass Spectra Online Database Excellent Online Spectra Database. Click here to view 1 Search methane molecule, CH4 2 Fragmentation pattern CH4 3 Mass Spectrum CH4 Mass/charge m/z Relative abundance Molecular ion peak, M+ Isotopic peak M+ + 1 Video on mass spectrometer Video Ionization/fragmentation Video how MS works Video how MS works Video Mass spectrometer
  26. 26. Using Mass spectrometry to determine Relative Isotopic Mass Mg - 3 Isotopes Mg - 11.3% - m/z highest – deflect LEAST Mg - 10.0% 24 Mg – 78.6% - m/z lowest – deflect MOST 26 25 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 Deflect MOST Deflect LEAST
  27. 27. Using Mass spectrometry to determine Relative Isotopic Mass Mg - 3 Isotopes Mg - 11.3% - m/z highest – deflect LEAST Mg - 10.0% 24 Mg – 78.6% - m/z lowest – deflect MOST 26 25 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 Deflect MOST Deflect LEAST Pb - 4 Isotopes Pb – 52% - m/z highest – deflect LEAST Pb - 22% 206 Pb - 24% 204 Pb – 2% - m/z lowest – deflect MOST 208 207 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
  28. 28. Using Mass spectrometry to determine Relative Isotopic Mass CI - 2 Isotopes 35 37 35 Relative Isotopic Mass: = (35CI x % Ab) + (37CI x % Ab) = (35 x 75.5/100) + (37 x 24.5/100) = 35.5 35 CI Deflect MOST CI 37 CI CI – 24.5% - m/z highest – deflect LEAST CI – 75.5% - m/z lowest – deflect MOST CI 37 Deflect LEAST
  29. 29. Using Mass spectrometry to determine Relative Isotopic Mass CI - 2 Isotopes 35 37 35 Relative Isotopic Mass: = (35CI x % Ab) + (37CI x % Ab) = (35 x 75.5/100) + (37 x 24.5/100) = 35.5 35 CI CI 37 CI CI – 24.5% - m/z highest – deflect LEAST CI – 75.5% - m/z lowest – deflect MOST CI 37 Deflect MOST Deflect LEAST Br - 2 Isotopes 79 Br 81 Br Br – 49.3% - m/z highest – deflect LEAST Br – 50.6% - m/z lowest – deflect MOST 81 79 Relative Isotopic Mass: = (79Br x % Ab) + (81Br x % Ab) = (79 x 50.6/100) + (81 x 49.3/100) = 79.9 79 Br 81 Br Deflect MOST Deflect LEAST
  30. 30. Using Mass spectrometry to determine Relative Isotopic Mass H - 3 Isotopes H 1 2 H H 3 H – trace amt H – 0.015% - m/z highest – deflect LEAST 1 H – 99.9% - m/z lowest – deflect MOST 3 2 Relative Isotopic Mass: = (1H x % Ab) + (2H x % Ab) = (1 x 99.9/100) + (2 x 0.015/100) = 1.007 1 H 2 H Deflect MOST Deflect LEAST
  31. 31. Using Mass spectrometry to determine Relative Isotopic Mass H - 3 Isotopes H 1 2 H H 3 H – trace amt H – 0.015% - m/z highest – deflect LEAST 1 H – 99.9% - m/z lowest – deflect MOST 3 2 Relative Isotopic Mass: = (1H x % Ab) + (2H x % Ab) = (1 x 99.9/100) + (2 x 0.015/100) = 1.007 1 H 2 H Deflect MOST Deflect LEAST C - 3 Isotopes 12 C C 13 14 C C- trace amt C – 1.1% - m/z highest – deflect LEAST 12 C – 98.9% - m/z lowest – deflect MOST 14 13 Relative Isotopic Mass: = (12C x % Ab) + (813Cx % Ab) = (12 x 98.9/100) + (13 x 1.1/100) = 12.01 12 C Deflect MOST 13 C Deflect LEAST
  32. 32. Ionization and Fragmentation Process- CH3CH2CH2CH3 Ionization Process - CH3CH2CH2CH3 • Bombarded by electron form cation • Molecular ion, M+ = 58 • (CH3CH2CH2CH3)+ = 58 Ionization M+, m/z = 58 CH3CH2CH2CH3 + e → CH3CH2CH2CH3+ + 2e H H | | CH3CH2CH2 C:H + e → CH3CH2CH2 C+.H + 2e m/z = 58 | | H H
  33. 33. Ionization and Fragmentation Process- CH3CH2CH2CH3 Fragmentation Process CH3CH2CH2CH3 • Molecular ion, M+ undergo fragmentation • Cation and Radical form • Cation - Detected • Radical –Not detected (No charged) Ionization Process - CH3CH2CH2CH3 • Bombarded by electron form cation • Molecular ion, M+ = 58 • (CH3CH2CH2CH3)+ = 58 Ionization M+, m/z = 58 Ionization and Fragmentation of M+ • Form - m/z = 58, 43 and 15 Ionization and Fragmentation of M+ • Form- m/z = 58 and 29 CH3CH2CH2CH3 + e → CH3CH2CH2CH3+ + 2e H H | | CH3CH2CH2 C:H + e → CH3CH2CH2 C+.H + 2e m/z = 58 | | H H Ionization forming M+ CH3CH2CH2 : CH3 + e → CH3CH2CH2+.CH3 + 2e m/z = 58 • Fragmentation of M producing 43 CH3CH2CH2+·CH3 → CH3CH2CH2+ + ·CH3 + m/z = 43 • Fragmentation of M producing 15 CH3CH2CH2+·CH3 → CH3CH2CH2· + +CH3 + m/z = 15 Ionization forming M+ CH3CH2:CH2CH3 + e → CH3CH2+·CH2CH3 + 2e m/z = 58 • Fragmentation of M producing 29 CH3CH2+·CH2CH3 → CH3CH2+ + .CH2CH3 + m/z = 29
  34. 34. Ionization and Fragmentation Process- CH3CH2CH2CH3 Fragmentation Process CH3CH2CH2CH3 • Molecular ion, M+ undergo fragmentation • Cation and Radical form • Cation - Detected • Radical –Not detected (No charged) Ionization Process - CH3CH2CH2CH3 • Bombarded by electron form cation • Molecular ion, M+ = 58 • (CH3CH2CH2CH3)+ = 58 Ionization M+, m/z = 58 Ionization and Fragmentation of M+ • Form - m/z = 58, 43 and 15 Ionization and Fragmentation of M+ • Form- m/z = 58 and 29 CH3CH2CH2CH3 + e → CH3CH2CH2CH3+ + 2e H H | | CH3CH2CH2 C:H + e → CH3CH2CH2 C+.H + 2e m/z = 58 | | H H Ionization forming M+ CH3CH2CH2 : CH3 + e → CH3CH2CH2+.CH3 + 2e m/z = 58 • Fragmentation of M producing 43 CH3CH2CH2+·CH3 → CH3CH2CH2+ + ·CH3 + m/z = 43 • Fragmentation of M producing 15 CH3CH2CH2+·CH3 → CH3CH2CH2· + +CH3 + m/z = 15 Ionization and Fragmentation Positively charged Unpair electron Will MOVE (ACCELARATED) NOT move Ionization forming M+ CH3CH2:CH2CH3 + e → CH3CH2+·CH2CH3 + 2e m/z = 58 • Fragmentation of M producing 29 CH3CH2+·CH2CH3 → CH3CH2+ + .CH2CH3 + m/z = 29
  35. 35. Mass spectrometry - Ionization/ Fragmentation pattern for CH 3CH2CH2CH3 CH3CH2CH2CH3 ionization Fra g me nta tion CH3CH2CH2CH3+ CH3CH2CH2+ CH3+ CH3CH2+ CH3CH2CH2CH3+- 58 - m/z highest –deflect LEAST CH3CH2CH2+ – 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST CH3+ Deflect MOST CH3CH2CH2CH3+ Deflect LEAST
  36. 36. Mass spectrometry - Ionization/ Fragmentation pattern for CH 3CH2CH2CH3 CH3CH2CH2CH3 ionization Fra g me nta tion CH3CH2CH2CH3+ CH3CH2CH2+ CH3+ CH3CH2+ CH3CH2CH2CH3+- 58 - m/z highest –deflect LEAST CH3CH2CH2+ – 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST CH3+ Ionization and Fragmentation Process CH3CH2CH2CH3 Ionization Ionization of CH3CH2CH2CH3 CH3CH2CH2CH3 + e → CH3CH2CH2CH3+ + 2e → 58 or CH3CH2:CH2CH3 + e → CH3CH2+·CH2CH3 + 2e → 58 CH3CH2CH2CH3+ Deflect MOST Fragmentation Mass spectrum CH3CH2CH2CH3 Fragmentation of M+ CH3CH2CH2+·CH3 → CH3CH2CH2+ - 43 CH3CH2+·CH2CH3 → CH3CH2+ CH3CH2CH2+·CH3 → +CH3 Deflect LEAST – 29 - 15 CH3CH2CH2CH3+- 58 - m/z highest –deflect LEAST CH3CH2CH2+ – 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST
  37. 37. Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH CH3CH2CH2OH Fra g ionization me nta tion CH3CH2CH2OH+ CH2CH2OH+ CH3CH2+ CH2OH+ CH3 + CH3CH2CH2OH+- 60 - m/z highest –deflect LEAST CH2CH2OH+ – 45 CH2OH+ - 31 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST 15 CH3+ Deflect MOST 60 CH3CH2CH2OH+ Deflect LEAST
  38. 38. Mass spectrometry - Ionization/ Fragmentation pattern for CH3CH2CH2OH CH3CH2CH2OH Fra g ionization me nta tion CH3CH2CH2OH+ CH2CH2OH+ CH3CH2+ CH2OH+ CH3 + CH3CH2CH2OH+- 60 - m/z highest –deflect LEAST CH2CH2OH+ – 45 CH2OH+ - 31 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST 15 CH3+ Deflect MOST Ionization and Fragmentation Process CH3CH2CH2OH Ionization Ionization of CH3CH2CH2OH CH3CH2CH2OH + e → CH3CH2CH2OH+ + 2e → 60 or CH3CH2CH2OH + e → CH3CH2+. CH2OH + 2e → 60 Fragmentation 60 CH3CH2CH2OH+ Deflect LEAST Mass spectrum CH3CH2CH2CH3 Fragmentation of M+ CH3 .CH2CH2OH→ +CH2CH2OH - 45 + CH3CH2+·CH2OH→ +CH2OH – 31 CH3CH2+·CH2OH→ CH3CH2+ – 29 CH3+.CH2CH2OH→ +CH3 CH3CH2CH2OH+- 60 - m/z highest – deflect LEAST CH2CH2OH+ – 45 CH2OH+ - 31 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST - 15 15 60
  39. 39. Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3 Ionization CH3CH(CH3)CH2CH3+ Fra g me nta tion CH3CH(CH3)CH2CH3+ CH3CH(CH3)CH2+ CH3CH2+ CH3CH(CH3)+ CH3+ CH3CH(CH3)CH2CH3+- 72 - m/z highest –deflect LEAST CH3CH(CH3)CH2+ – 57 CH3CH(CH3)+ - 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST 15 CH3+ Deflect MOST CH3CH(CH3)CH2CH3+ Deflect LEAST
  40. 40. Mass spectrometry - Ionization/ Fragmentation pattern CH3CH(CH3)CH2CH3 Ionization CH3CH(CH3)CH2CH3+ Fra g me nta tion CH3CH(CH3)CH2CH3+ CH3CH(CH3)CH2+ CH3CH2+ CH3CH(CH3)+ CH3+ CH3CH(CH3)CH2CH3+- 72 - m/z highest –deflect LEAST CH3CH(CH3)CH2+ – 57 CH3CH(CH3)+ - 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST 15 CH3+ Deflect MOST Ionization and Fragmentation Process CH3CH(CH3)CH2CH3 Ionization Fragmentation Ionization of CH3CH(CH3)CH2CH3 CH3CH(CH3)CH2CH3 + e → CH3CH(CH3)CH2CH3 + 2e → 72 or CH3CH(CH3)CH2CH3 + e → CH3CH(CH3)CH2+.CH3+ 2e → 72 or CH3CH(CH3)CH2CH3 + e → CH3CH(CH3)+.CH2CH3 + 2e → 72 + Fragmentation of M+ CH3CH(CH3)CH2+ - 57 CH3CH(CH3)+ – 43 CH3CH2+ – 29 CH3+ - 15 CH3CH(CH3)CH2CH3+ Deflect LEAST Mass spectrum CH3CH(CH3)CH2CH3 CH3CH(CH3)CH2CH3+- 72 - m/z highest –deflect LEAST CH3CH(CH3)CH2+ – 57 CH3CH(CH3)+ - 43 CH3CH2+ – 29 CH3+ –15 - m/z lowest– deflect MOST
  41. 41. Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4 (C(CH3)4)+ Ionization (C(CH3)4) Fragm entatio n (C(CH3)3)+ (C(CH3)2)+ (C(CH3))+ CH3+ (C(CH3)4)+ (C(CH3)3)+ (C(CH3)2)+ (C(CH3))+ CH3+ CH3+ Deflect MOST - 72 - m/z highest –deflect LEAST – 57 - 42 – 27 –15 - m/z lowest– deflect MOST (C(CH3)4)+ Deflect LEAST
  42. 42. Mass spectrometry - Ionization/ Fragmentation pattern C(CH3)4 (C(CH3)4)+ Ionization (C(CH3)4) Fragm entatio n (C(CH3)3)+ (C(CH3)2)+ (C(CH3))+ CH3+ (C(CH3)4)+ (C(CH3)3)+ (C(CH3)2)+ (C(CH3))+ CH3+ CH3+ Ionization and Fragmentation Process C(CH3)4 Ionization Ionization of C(CH3)4 C(CH3)4 + e → (C(CH3)4)+ + 2e → 72 (C(CH3)4)+ Deflect MOST Fragmentation Fragmentation of M+ (C(CH3)3)+ – 57 (C(CH3)2)+ - 42 (C(CH3))+ – 27 CH3+ –15 - 72 - m/z highest –deflect LEAST – 57 - 42 – 27 –15 - m/z lowest– deflect MOST Deflect LEAST Mass spectrum C(CH3)4 (C(CH3)4)+ (C(CH3)3)+ (C(CH3)2)+ (C(CH3))+ CH3+ - 72 - m/z highest –deflect LEAST – 57 - 42 – 27 –15 - m/z lowest– deflect MOST
  43. 43. Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI 2 CI2molecule 35 Ionization Fra gm for enta m a tio tom n s 35 CI-35CI+ CI+ 35 37 CI-37CI+ 37 CI-37CI+ CI+ CI-37CI - 74 - m/z highest – deflect LEAST CI-37CI –72 35 CI-35CI –70 37 CI –37 35 CI –35 - m/z lowest– deflect MOST 37 35 35 CI+ Deflect MOST 37 CI-37CI+ Deflect LEAST
  44. 44. Mass spectrometry - Ionization/ Fragmentation pattern for molecule CI 2 CI2molecule 35 Ionization Fra gm for enta m a tio tom n s 35 CI-35CI+ CI+ 35 37 CI-37CI+ 37 CI-37CI+ CI+ CI-37CI - 74 - m/z highest – deflect LEAST CI-37CI –72 35 CI-35CI –70 37 CI –37 35 CI –35 - m/z lowest– deflect MOST 37 35 35 CI+ 37 Deflect MOST CI-37CI+ Deflect LEAST Ionization and Fragmentation Process CI2 molecule Ionization Fragmentation Ionization of CI2 to CI2+ CI:CI + e- → [35CI+.35CI] + 2e – 70 CI:CI + e- → [35CI+.37CI] + 2e – 72 CI:CI + e- → [37CI+.37CI] + 2e – 74 Fragmentation of CI2+ into CI+ CI+.CI → [35CI+ + 35CI·] + 2e –35 Ratio (35CI35CI: 35CI37CI: 37CI37CI) - 9:6:1 Ratio (35CI : 37CI) - 3:1 m/z = 35 CI+.CI → [37CI+ + m/z = 37 CI·] + 2e –37 37 Mass spectrum CI2 / CI atoms CI-37CI - 74 - m/z highest – deflect LEAST CI-37CI –72 35 CI-35CI –70 37 CI –37 35 CI –35 - m/z lowest– deflect MOST 37 35
  45. 45. Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br 2 Br2molecule 79 Ionization Fra gm for enta m a tio tom n s 79 Br-79Br+ Br+ 79 Br-81Br+ Br-81Br+ 81 Br+ 81 Br-81Br - 162 - m/z highest – deflect LEAST Br-81Br –160 79 Br-79Br –158 81 Br –81 79 Br –79 - m/z lowest– deflect MOST 81 79 Br+ 79 Deflect MOST Br-81Br+ 81 Deflect LEAST
  46. 46. Mass spectrometry - Ionization/ Fragmentation pattern for molecule Br 2 Br2molecule 79 Ionization Fra gm for enta m a tio tom n s 79 Br-79Br+ Br+ 79 Br-81Br+ Br-81Br+ 81 Br+ 81 Br-81Br - 162 - m/z highest – deflect LEAST Br-81Br –160 79 Br-79Br –158 81 Br –81 79 Br –79 - m/z lowest– deflect MOST 81 79 Br+ Br-81Br+ 79 Deflect MOST Ionization and Fragmentation Process Br2 molecule Ionization Ionization of Br2 to Br2+ Br:Br + e- → [81Br+.81Br] + 2e – 162 Br:Br + e- → [79Br+.81Br] + 2e – 160 Br:Br + e- → [79Br+.79Br] + 2e– 158 Deflect LEAST Fragmentation Fragmentation of Br2+ to Br+ Br+.Br → [81Br+ + 81Br·] – 81 m/z = 81 Br+.Br → [79Br+ + 79Br·] – 79 m/z = 79 Ratio (79Br79Br: 79Br81Br: 81Br81Br) – 1:2:1 81 Ratio (79Br : 81Br) - 1:1 Mass spectrum Br2 / Br atoms Br-81Br Br-81Br 79 Br-79Br 81 Br 79 Br 81 79 - 162 - m/z highest – deflect LEAST –160 –158 – 81 – 79 - m/z lowest– deflect MOST
  47. 47. Acknowledgements Thanks to source of pictures and video used in this presentation http://serc.carleton.edu/research_education/geochemsheets/techniques/gassourcemassspec.html http://www.mhhe.com/physsci/chemistry/carey/student/olc/ch13ms.html http://science.howstuffworks.com/mass-spectrometry3.htm Thanks to Creative Commons for excellent contribution on licenses http://creativecommons.org/licenses/ Prepared by Lawrence Kok Check out more video tutorials from my site and hope you enjoy this tutorial http://lawrencekok.blogspot.com
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×