MALDI-MS
Matrix Assisted Desorption/Ionization
Mass Spectrometry
, Introduction
Mass Spectrometry (MS)
Vital tool used to characterize and analyze molecules
Limitations
Biomolecules and organic macromolecules are fragile
Molecular ions or meaningful fragments were limited to only 5-
10 kDa at the time
New technique
In 1987, Michael Karas and Franz Hillenkamp successfully
demonstrated the use of a matrix to ionize high molecular
weight compounds.
, MALDI
Matrix Assisted Laser Desorption/Ionization (MALDI)
Method where a laser is used to generate ions of high molecular
weight samples, such as proteins and polymers.
Analyte is embedded in to crystal matrix
The presence of an aromatic matrix causes the large molecules to
ionize instead of decomposing.
, MALDI
The mechanism remains
uncertain
It may involve absorption of
light by the matrix
Transfer of this energy to the
analyte
which then ionizes into the gas
phase as a result of the relatively
large amount of energy
absorbed.
To accelerate the resulting ions
into a flight-tube in the mass
spectrometer they are subjected
to a high electrical field.
Matrix Assisted Desorption/Ionization
Mass Spectrometry
, Introduction
Mass Spectrometry (MS)
Vital tool used to characterize and analyze molecules
Limitations
Biomolecules and organic macromolecules are fragile
Molecular ions or meaningful fragments were limited to only 5-
10 kDa at the time
New technique
In 1987, Michael Karas and Franz Hillenkamp successfully
demonstrated the use of a matrix to ionize high molecular
weight compounds.
, MALDI
Matrix Assisted Laser Desorption/Ionization (MALDI)
Method where a laser is used to generate ions of high molecular
weight samples, such as proteins and polymers.
Analyte is embedded in to crystal matrix
The presence of an aromatic matrix causes the large molecules to
ionize instead of decomposing.
, MALDI
The mechanism remains
uncertain
It may involve absorption of
light by the matrix
Transfer of this energy to the
analyte
which then ionizes into the gas
phase as a result of the relatively
large amount of energy
absorbed.
To accelerate the resulting ions
into a flight-tube in the mass
spectrometer they are subjected
to a high electrical field.
