What is MALDI and TOF?
MALDI, or Matrix-Assisted Laser Desorption Ionization, is a solid-phase ionization technique in which samples are dissolved in a solution containing a chromophoric matrix. The matrix-sample mixture is dried on a target plate and subjected to laser irradiation. As the matrix absorbs energy from the laser, it desorbs (vaporizes) and ionizes, and transfers charge to the sample that was desorbed with the matrix. TOF, or time-of-flight, is mass analysis technique in which ions are separated, based on the time it takes for them to travel over a given distance. In a TOF MS ions of like charge are simultaneously emitted from the source with the same initial kinetic energy. Those with a lower mass will have a higher velocity and reach the detector earlier than ions with a higher mass.
