Matrix Assisted Laser Desorption Ionisation Time Of Flight MS (MALDI-TOF MS)

MALDI-TOF MS, Matrix Assisted Laser Desorption Ionisation-Time Of Flight MS, involves mixing the sample with a matrix, which is then coated on to a plate or probe, and subjected to a collimated focused laser beam, causing ionisation and desorption. MALDI enables analysis of molecules up to approximately 500kDa and has the advantage of producing large mass ions, with high sensitivity and little fragmentation. MALDI is now commonly coupled with Delayed Extraction (DE-MALDI), causing the produced ions to enter the Time Of Flight analyser at the same time.

MALDI-TOF MS is used to determine molecular weight and may be employed in a large number of biochemical applications:

MALDI-TOF is used extensively for the determination of average molecular weight and polydispersity of certain polymers such as polystyrene, PMMA, PEG and a wide range of alkoxylated products, including non-ionic detergents such as alkylphenol ethoxylates, alcohol propoxylates and gasoline dispersants. The molecular weight range of intact triglycerides and other lipids can also be identified by MALDI-TOF.