What are the components of MALDI - TOP - MS? Write the function of any four components in brief.
Answers
MALDI is a soft ionization that involves a laser striking a matrix of small molecules to make the analyte molecules into the gas phase without fragmenting or decomposing them. Some biomolecules are too large and can decompose when heated, and traditional techniques will fragment or destroy macromolecules. MALDI is appropriate to analyze biomolecules like peptides, lipids, saccharides, or other organic macromolecules.
The principle of MALDI
the analyte is embedded in a very large excess of a matrix compound deposited on a solid surface called a target, usually made of a conducting metal and having spots for several different samples to be applied. After a very brief laser pulse, the irradiated spot is rapidly heated and becomes vibrationally excited. The matrix molecules energetically ablated from the surface of the sample, absorb the laser energy and carry the analyte molecules into the gas phase as well. During the ablation process, the analyte molecules are usually ionized by being protonated or deprotonated with the nearby matrix molecules. The most common MALDI ionization format is for analyte molecules to carry a single positive charge.