Successfully reported this slideshow.
MEDICAL RESEARCH INSTITUTE– ALEXANDRIA UNIVERSITY

15 th conference (3 rd international)

ADVANCES IN MEDICAL RESEARCH

` ...
Mass Spectrometry
Mass spectrometry (MS)
Mass spectrometry is a powerful analytical
technique that is used to identify unknown
compounds, to...
Mass spectrometry
I. Sample Ionization
Simple Definition:
Ionization is a process of charging
a molecule.
Molecules must be charged in
order to
measure them usin...
Types
Of ionizing radiation
Important to determine the target
from analyte investigated
Hard ionization: the resulting unique fragmentation
patterns can be used as a fingerprint for the
identification of the sa...
Mass spectrometry
Chemical ionization
A proton is transferred to or abstracted
from ,a gas phase analyte by a reagent
gas molecule
 Little ...
Electrospray-2
(Ionization (ESI
Electro spray ionization
The 2002 Nobel Prize in
Chemistry was awarded to
two mass spectrometrists
(J. Fenn and K. Tanaka) for
their

development

...
3-Matrix Assisted
Laser Desorption
Ionization (MALDI)
SELDI
Modification of MALDI surface a type of affinitycapture property
Sample of interest is exposed to affinity surface ,...
II. Analysis and Separation of
Sample Ions
The mass analyzer separates the ions formed
in the ionization source according to their
mass-to-charge (m/z) ratios using ...
Time Of Flight Mass Analyzer
(TOF)
Quadrupole Mass Analyzer
. III. Detection of sample ions
• A tiny current is produced when the ion
reaches the detector.
• The detector amplifies the signals which are
then transm...
Mass spectruM

m/z
Mass spectrum of CO2
Mass spectrum
Questions needs to be asked??
1.Negative or positive mode
2.Types of ion source result in different
arrays o...
Interpretation of mass spectra

• compare its experimental mass spectrum against a
library of mass spectra
library of mass...
Mass spectrometry
Techniques
Of mass spectrometry
• GC –MS :
1.Definitive method to quantify
standard reference materials
2.Identifying trac...
Techniques
Of mass spectrometry
• HPLC –MS :
1.Screening & confirmation in
inborn errors of metabolism
2.Analysis of amino...
MALDI
SELDI-TOF
Tandem Mass Spectrometry
A tandem mass spectrometer is a mass
spectrometer that has more than one
analyser, usually two, w...
MS/MS uses 2 stages of mass analysis:
1. Selection of an ion
2. Analysis of ion fragments produced by collision with inert...
Phe

Subs B
APPLICATIONS OF mass spectrometry

Pharmacokinetics
New born screening

Proteomics and mass
spectrometry
applications of mass spectrometry
to study proteins

Best two techniques:

•ESI
•MALDI

Using two approaches:

•Top-Down
•...
Newborn screening (NBS)
MS/MS allows the screening of a numerous
array of metabolic disorders in a single
analytical run:
• Amino Acid Disorders
P...
intensity%
Advantages of MS/MS as a screening tool
in NBS
 Sensitive
 Specific
 Accurate Quantitation
 Internal standards: gold s...
applications of mass spectrometry
to study proteins

Best techniques:

•ESI - Quadrupole
•MALDI-TOF
•SELDI-TOF
TOP-DOWN approach

intact proteins are ionized
by either of the three
techniques described
above, and then introduced
to a...
BOTTOM-UP approach
Bottom-up proteomics is a common
method to identify proteins and
characterize their amino acid
sequence...
applications of mass spectrometry
to study proteins




Identifying unknown proteins

Protein sequencing ( peptides are
...
applications of mass spectrometry
to study proteins

Identification of chemical modification
( post-translational modific...
Mass spectrometry basic principles
Mass spectrometry basic principles
Mass spectrometry basic principles
Mass spectrometry basic principles
Upcoming SlideShare
Loading in …5
×

Mass spectrometry basic principles

18,888 views

Published on

(MS) is an analytical technique that produces spectra (singular spectrum) of the masses of the atoms or molecules comprising a sample of material. The spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical structures of molecules, such as peptides and other chemical compounds,so it is considered one f the very important diagnostic analytical techniques .

  • Be the first to comment

Mass spectrometry basic principles

  1. 1. MEDICAL RESEARCH INSTITUTE– ALEXANDRIA UNIVERSITY 15 th conference (3 rd international) ADVANCES IN MEDICAL RESEARCH ` From molecular medicine-to clinical application` Mass spectrometric techniques RANIA MOHAMED EL-SHARKAWY Lecturer of clinical chemistry , Medical Research Institute Alexandria University
  2. 2. Mass Spectrometry
  3. 3. Mass spectrometry (MS) Mass spectrometry is a powerful analytical technique that is used to identify unknown compounds, to quantify known materials, and to elucidate the structure and chemical properties of molecules A mass spectrometer is a device that measures the mass-to-charge (m/z) ratio of ions.
  4. 4. Mass spectrometry
  5. 5. I. Sample Ionization
  6. 6. Simple Definition: Ionization is a process of charging a molecule. Molecules must be charged in order to measure them using a mass spectrometer
  7. 7. Types Of ionizing radiation Important to determine the target from analyte investigated
  8. 8. Hard ionization: the resulting unique fragmentation patterns can be used as a fingerprint for the identification of the sample. Fragment ions also provide important information about the primary structure . (i.e. sequence) of the sample molecules Soft ionization is applied to a stable molecule, the exact m/z value of its stable molecular thus, allows for the compositional analysis of the sample of unknown structure under .study
  9. 9. Mass spectrometry
  10. 10. Chemical ionization A proton is transferred to or abstracted from ,a gas phase analyte by a reagent gas molecule  Little or no fragmentation as the protonated molecule is not highly excited in the chemical ionization Uses: analyte molecular mass determination & quantification
  11. 11. Electrospray-2 (Ionization (ESI
  12. 12. Electro spray ionization
  13. 13. The 2002 Nobel Prize in Chemistry was awarded to two mass spectrometrists (J. Fenn and K. Tanaka) for their development ionization of techniques, which include electrospray ionization
  14. 14. 3-Matrix Assisted Laser Desorption Ionization (MALDI)
  15. 15. SELDI Modification of MALDI surface a type of affinitycapture property Sample of interest is exposed to affinity surface ,certain analyte will preferentially bind Washing to remove excessMatrix is added to asset ionizationUses: analysis of protein mixture with low sample size (purification&analysis occur on the same surface
  16. 16. II. Analysis and Separation of Sample Ions
  17. 17. The mass analyzer separates the ions formed in the ionization source according to their mass-to-charge (m/z) ratios using some physical property e.g. electric or magnetic fields.
  18. 18. Time Of Flight Mass Analyzer (TOF)
  19. 19. Quadrupole Mass Analyzer
  20. 20. . III. Detection of sample ions
  21. 21. • A tiny current is produced when the ion reaches the detector. • The detector amplifies the signals which are then transmitted to the data system to be represented as peaks on a mass spectrum Mass spectrum: graphic representation of ions separated according to their m/z ratio
  22. 22. Mass spectruM m/z
  23. 23. Mass spectrum of CO2
  24. 24. Mass spectrum Questions needs to be asked?? 1.Negative or positive mode 2.Types of ion source result in different arrays of fragments produced from the original molecules. 3.origin of a sample 4. How the sample was prepared ??
  25. 25. Interpretation of mass spectra • compare its experimental mass spectrum against a library of mass spectra library of mass spectra • If the search comes up empty, then manual interpretation or software assisted interpretation of mass spectra are performed •A recent technique for structure elucidation in mass spectrometry, called precursor ion fingerprinting identifies individual pieces of structural information by conducting a search of the tandem spectra of the molecule under investigation against a library of the product-ion spectra of structurally characterized precursor
  26. 26. Mass spectrometry
  27. 27. Techniques Of mass spectrometry • GC –MS : 1.Definitive method to quantify standard reference materials 2.Identifying trace contaminants or toxins 3.Identification of drugs
  28. 28. Techniques Of mass spectrometry • HPLC –MS : 1.Screening & confirmation in inborn errors of metabolism 2.Analysis of amino acids
  29. 29. MALDI
  30. 30. SELDI-TOF
  31. 31. Tandem Mass Spectrometry A tandem mass spectrometer is a mass spectrometer that has more than one analyser, usually two, with a collision chamber in between.
  32. 32. MS/MS uses 2 stages of mass analysis: 1. Selection of an ion 2. Analysis of ion fragments produced by collision with inert gas.
  33. 33. Phe Subs B
  34. 34. APPLICATIONS OF mass spectrometry Pharmacokinetics New born screening Proteomics and mass spectrometry
  35. 35. applications of mass spectrometry to study proteins Best two techniques: •ESI •MALDI Using two approaches: •Top-Down •Bottom-Up
  36. 36. Newborn screening (NBS)
  37. 37. MS/MS allows the screening of a numerous array of metabolic disorders in a single analytical run: • Amino Acid Disorders PKU, MSUD, Tyr, Cit, etc • Fatty Acid Oxidation Disorders MCAD, VLCAD, LCHAD, etc. • Organic Acid Disorders PA, MMA, IVA, GA-1, etc
  38. 38. intensity%
  39. 39. Advantages of MS/MS as a screening tool in NBS  Sensitive  Specific  Accurate Quantitation  Internal standards: gold standard for accuracy  High impact  Multiple Metabolite, Multiple Disease Screening  cost effective  High throughput
  40. 40. applications of mass spectrometry to study proteins Best techniques: •ESI - Quadrupole •MALDI-TOF •SELDI-TOF
  41. 41. TOP-DOWN approach intact proteins are ionized by either of the three techniques described above, and then introduced to a mass analyzer
  42. 42. BOTTOM-UP approach Bottom-up proteomics is a common method to identify proteins and characterize their amino acid sequences and post-translational modifications by proteolytic digestion of proteins prior to analysis by mass spectrometry.
  43. 43. applications of mass spectrometry to study proteins   Identifying unknown proteins Protein sequencing ( peptides are sequenced by generating multiple sets of peptides)
  44. 44. applications of mass spectrometry to study proteins Identification of chemical modification ( post-translational modification in proteins after synthesis)  Identification of organisms (identifying bacteria by finger printing proteins)

×