Matrix (mass spectrometry)


In mass spectrometry, a matrix is a compound that promotes the formation of ions. Matrix compounds are used in matrix-assisted laser desorption/ionization, matrix-assisted ionization, and fast atom bombardment.

Matrix-assisted laser desorption/ionization

MALDI is an ionization technique where laser energy is absorbed by a matrix to create ions from large molecules without fragmentation. The matrix, typically in excess, is mixed with the analyze molecule and deposited on a target. A table of matrix compounds, their structures, laser wavelengths typically used, and typical application is shown below.
CompoundAbbreviationStructureWavelength Applications
9-aminoacridine9AA337lipids, metabolites
α-cyano-4-hydroxycinnamic acidCHCA337, 355peptides, lipids, nucleotides
ferulic acidFA337, 355, 266proteins
DHB337, 355peptides, nucleotides, oligonucleotides, oligosaccharides
3-hydroxy picolinic acidHPA337, 355oligonucleotides
picolinic acidPA266oligonucleotides
sinapinic acidSA337, 355, 266peptides, proteins, lipids

Matrix-assisted ionization

Matrix-assisted ionization is an ionization method in mass spectrometry that creates ions via the creation of particles at atmospheric pressure and transfer to the vacuum of the mass analyzer.
CompoundAbbreviationStructure
2,5-dihydroxybenzoic acidDHB
2-aminobenzyl alcohol
anthranilic acid
2-hydroxyacetophenone

Fast atom bombardment

FAB uses a high energy beam of atoms directed at a surface to create ions. FAB matrix compounds are typically liquids.
CompoundAbbreviationStructure
glycerol
thioglycerol
3-nitrobenzyl alcoholNBA
18-crown-6 ether
2-nitrophenyloctyl etherNPOE
diethanolamine
triethanolamine