Maldi-tof

Matrix-assisted laser ionization-time of flight:
Laser desorption: produces gaseous ions, Laser pulses yielding from 106 to 1010 Wcm−2 .

2 principles of MALDI-TOF

step 1. create the matrix:  the compound to be analysed is dissolved in
a solvent containing in solution small organic molecules, called the matrix.
These molecules must have a strong absorption at the laser wavelength. This mixture is dried before analysis and any liquid solvent used in the preparation of the solution is removed. The result is
a ‘solid solution’ deposit of analyte-doped matrix crystals. The analyte molecules are
embedded throughout the matrix so that they are completely isolated from one another .
Step 2: desorption and then ionization by radiation of laser.