1

Ion Information and Elemental Patterns

Chapter 6 (Hoffmann amp Stroobant)

Chapter 1 (Johnstone and Rose 1996)

2

Two Main Facets of Mass Spectrometry

bull Compared with most other common methods of physicochemical spectroscopic analysis some or all of the samples is consumed

bull MS does not deal with a well-defined property of a molecule The appearance of a mass spectrum depends on the compounds itself but also upon the interval of time between ionization and detection initial energy distribution in the molecule ionization method etchellip

3

MS Spectral Collections and Database

bull NISTEPANIH gt190000 spectra (over 163000 compounds)

bull Wiley Registry of Mass Spectral Data 380000 spectra (over 200000 compounds)

bull Eight-Peak Index of Mass Spectra 81000 spectra (over 65000 compounds)

4

5

RICUsed when

background and unwanted impurities

are removed

RA is affected by the error in

measuring base peak

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

2

Two Main Facets of Mass Spectrometry

bull Compared with most other common methods of physicochemical spectroscopic analysis some or all of the samples is consumed

bull MS does not deal with a well-defined property of a molecule The appearance of a mass spectrum depends on the compounds itself but also upon the interval of time between ionization and detection initial energy distribution in the molecule ionization method etchellip

3

MS Spectral Collections and Database

bull NISTEPANIH gt190000 spectra (over 163000 compounds)

bull Wiley Registry of Mass Spectral Data 380000 spectra (over 200000 compounds)

bull Eight-Peak Index of Mass Spectra 81000 spectra (over 65000 compounds)

4

5

RICUsed when

background and unwanted impurities

are removed

RA is affected by the error in

measuring base peak

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

3

MS Spectral Collections and Database

bull NISTEPANIH gt190000 spectra (over 163000 compounds)

bull Wiley Registry of Mass Spectral Data 380000 spectra (over 200000 compounds)

bull Eight-Peak Index of Mass Spectra 81000 spectra (over 65000 compounds)

4

5

RICUsed when

background and unwanted impurities

are removed

RA is affected by the error in

measuring base peak

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

4

5

RICUsed when

background and unwanted impurities

are removed

RA is affected by the error in

measuring base peak

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

5

RICUsed when

background and unwanted impurities

are removed

RA is affected by the error in

measuring base peak

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

6

Multiply Charged Ions

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

7

bull The ions in a mass spectrometer that have sufficient energy to fragment sometime after leaving the ion source but before arriving at the detector

bull M+ A+ + N

(m1z) (m2z) (m1-m2)

1 M+ with large amount of internal energy will fragment in the ionization source producing ldquonormalrdquo A+ ions These A+ ions will be seen as narrow peaks at mz values correct for the mass and charge on the ion A+

2 M+ having only a small excess of internal energy reach detector before decomposition can occur Narrow peaks for ldquonormalrdquo M+ appear

3 M+ which posses excesses of internal energy that are in between the those in above two cases may fragment after leaving the ion source and before reaching the detector The product ions A+ are seen in the mass spectrum as broad peaks centered at mz values that are nor correct for the mass and charge on the ion A+

Metastable ions

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

8

bull These broad peaks are called ldquometastable ion peaksrdquo

bull These ldquoldquometastable ion peaksrdquo do not represent metastable M+ ions but represent products of decomposition of metastable ions

bull The cause of A+ ions from metastable ion decomposition being detected differently form ldquonormalrdquo A+ ions is due to their different momenta

Metastable ions

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

9

Metastable Ions

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

10

93

66

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

11

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

12

Just for clarification

Atomic massamu atomic mass units (uma)ldquoDardquo or Dalton kD (kiloDalton) 1 amu = 16605610

-27

kg proton mp = 16726510

-27

kg neutron mn = 16749510

-27

kg

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

13

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

14

Exact Masses of Some Common Elements and Their Isotopes

Element Symbol Exact Mass (u) Rel Abundance

Hydrogen 1H 1007825037 1000

Deuterium 2H or D

2014101787 0015

Carbon 12 12C 1200000 1000

Carbon 13 13C 13003354 111223

Nitrogen 14 14N 14003074 1000

Nitrogen 15 15N 1500011 036734

Oxygen 16 16O 1599491464 1000

Oxygen 17 17O 169991306 003809

Oxygen 18 18O 1799915939 020048

Fluorine 19F 18998405 1000

Sodium 23Na 229897697 1000

Silicon 28 28Si 279769284 9223

Silicon 29 29Si 289764964 50634

Silicon 30 30Si 299737717 33612

Phosphorus 31P 309737634 1000

Sulfur 32 32S 31972074 1000

Sulfur 33 33S 329707 078931

Sulfur 34 34S 3396938 443065

Sulfur 36 36S 3596676 002105

Chlorine 35 35Cl 34968854 1000

Chlorine 37 37Cl 36965896 3197836

See Table 4A for more elements

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

15

Isotopic peaks

bull Mass spectrum of methane CH4

mz =16 (12CH4) and mz = 17 (13CH4)

relative abundance = 991

bull For a compound with 10 carbons (C10H18)

The chance of incorporating one 13C into the molecule will be 10 times more Therefore [M+1]+ would be 10 x108 = 108 percent of the abundance of [M]+ (see slide 5)

bull For a compound with 10 carbons the approximate relative heights of the [M]+ [M+1]+ [M+2]+ and [M+3]+ peaks are 10010045001

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

16

Isotopic Peaks

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

17

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

18

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

19

(a) only one chlorine atom (b) only one bromine atom

c) one chlorine and one bromine atom

31 11

341

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

20

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

21

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

22

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

23

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

24

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

25

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

26

Molecular ions

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

27

Normalized Mass Spectra

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

28

Normalized Mass Spectra

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

29

Directly Recorded Mass Spectra

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

30

Computerized Mass Spectra

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

31

Accurate mass determination to several decimal places using a doublendashfocusing mass spectrometer enables the determination of molecular formulae and elemental compositions

High Resolution Accurate Mass Measurement Elemental Compositions

For an ion of NH3 the measured integer mass would be 17 viz mz = 171 = 17 for z = 1

In theory this process can be reversed in that any measured mass leads to an elemental composition

bull For example a measured value of 17 would imply the composition NH3

bull In practice there are other elemental compositions which could add up to 17 For example OH (oxygen = 16 hydrogen = 1) CD2H (carbon = 12 deuterium = 22 hydrogen = 1)

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

32

High Resolution Accurate Mass Measurement Elemental Compositions

For larger masses the possibilities increase enormously

ndash At mass 100 there would be literally thousands of possible elemental compositions unit mass is not enough

bull In fact atomic masses are not integers

ndash C = 120000 ndash O = 159949 ndash N = 140031 ndash H = 10078 and so onhellip

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265 The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are potentially separable

A mass spectrometer which can measure mass correct to several decimal places rather than just integer mass can be used to measure such differences RESOLUTION IS IMPORTANT ELEMENTAL ANALYSIS

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

33

mz measured5804189

C3H6O

Accurate Mass Determination

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

34

Exact masses and corresponding formulae for various possible ions of mz 180 containing only carbon hydrogen nitrogen and oxygen atoms in

limited number (C6-15 H0-24 N0-4 and O0-4)

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

35

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

36

What is mass resolution

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

37

The accurate mass for ammonia (NH3 ) is 140031 + 3 x 10078 = 170265

The accurate mass of OH is 159949 + 10078 = 170027

giving a mass difference of 00238 units between NH3 and OH which are

potentially separable

m = 00238 amu

m= 170265 amu for NH3

Minimum resolution required

R = 17026500238 = 7154

Lets go back to resolution what do I need to separate them

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

38

How good is good

5000 resolution separate mz 50000 from mz 50010

mz 10000 from mz 10002

mz 10000 from mz 10002

mz 10000 from mz 10002

Unit resolution mz 50 from mz 51

mz 100 from mz 101

mz 1000 from mz 1001

H

h

(hH)x100 le 10

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

39

500 10000

Clenbuterol mz 355

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

40

Sensitivity vs selectivity

When resolution is not a good thing

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41

41

• Ion Information and Elemental Patterns
• Two Main Facets of Mass Spectrometry
• MS Spectral Collections and Database
• Slide 4
• Slide 5
• Multiply Charged Ions
• Metastable ions
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Just for clarification
• Slide 13
• Slide 14
• Isotopic peaks
• Isotopic Peaks
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Normalized Mass Spectra
• Slide 28
• Slide 29
• Computerized Mass Spectra
• High Resolution Accurate Mass Measurement Elemental Compositions
• Slide 32
• Slide 33
• Slide 34
• Slide 35
• Slide 36
• Slide 37
• How good is good
• Slide 39
• Slide 40
• Slide 41