Matrix (mass spectrometry) explained

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

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 analyte molecule and deposited on a target. A table of matrix compounds, their structures, laser wavelengths typically used, and typical application is shown below.

MALDI Matrix List! Compound !! Abbreviation !! Structure !! Wavelength (nm) !! Applications

9-aminoacridine^[1]	9AA		337	lipids, metabolites
α-cyano-4-hydroxycinnamic acid^[2]	CHCA		337, 355	peptides, lipids, nucleotides
ferulic acid	FA		337, 355, 266	proteins
2,5-dihydroxy benzoic acid	^[3]	DHB		337, 355	peptides, nucleotides, oligonucleotides, oligosaccharides
3-hydroxy picolinic acid^[4]	HPA		337, 355	oligonucleotides
picolinic acid^[5]	PA		266	oligonucleotides
sinapinic acid^[6] ^[7]	SA		337, 355, 266	peptides, 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.^[8]

List of Matrix-assisted Ionization Compounds^[9] ! Compound !! Abbreviation !! Structure

2,5-dihydroxybenzoic acid	DHB
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.^[10] FAB matrix compounds are typically liquids.

FAB Matrix List! Compound !! Abbreviation !! Structure

glycerol
thioglycerol
3-nitrobenzyl alcohol	NBA
18-crown-6 ether
2-nitrophenyloctyl ether	NPOE
diethanolamine
triethanolamine

See also

• Desorption/ionization on silicon

Notes and References

1. Vermillion-Salsbury. Rachal L.. Hercules. David M.. 9-Aminoacridine as a matrix for negative mode matrix-assisted laser desorption/ionization. Rapid Communications in Mass Spectrometry. 16. 16. 2002. 1575–1581. 0951-4198. 10.1002/rcm.750.
2. Beavis . R. C. . Chaudhary . T. . Chait . B. T. . 1992 . α-Cyano-4-hydroxycinnamic acid as a matrix for matrix-assisted laser desorption mass spectrometry . . 27 . 2 . 156–8 . 10.1002/oms.1210270217 .
3. Strupat . K. . Karas . M. . Hillenkamp . F. . 1991 . 2,5-Dihidroxybenzoic acid: A new matrix for laser desorption—ionization mass spectrometry . . 72 . 111 . 89–102 . 1991IJMSI.111...89S . 10.1016/0168-1176(91)85050-V .
4. Wu . K. J. . Steding . A. . Becker . C. H. . 1993 . Matrix-assisted laser desorption time-of-flight mass spectrometry of oligonucleotides using 3-hydroxypicolinic acid as an ultraviolet-sensitive matrix . . 7 . 2 . 142–6 . 10.1002/rcm.1290070206 . 8457722 . 1993RCMS....7..142W .
5. Tang . K. . Taranenko . N. I. . Allman . S. L. . Cháng . L. Y. . Chen . C. H. . Lubman . D. M. . 1994 . Detection of 500-nucleotide DNA by laser desorption mass spectrometry . . 8 . 9 . 727–30 . 10.1002/rcm.1290080913 . 7949335 . 1994RCMS....8..727T .
6. Beavis . R. C. . Chait . B. T. . Standing . K. G. . 1989 . Matrix-assisted laser-desorption mass spectrometry using 355 nm radiation . . 3 . 12 . 436–9 . 10.1002/rcm.1290031208 . 2520224 . 1989RCMS....3..436B .
7. Beavis . R. C. . Chait . B. T. . Fales . H. M. . 1989 . Cinnamic acid derivatives as matrices for ultraviolet laser desorption mass spectrometry of proteins . . 3 . 12 . 432–5 . 10.1002/rcm.1290031207 . 2520223 . 1989RCMS....3..432B .
8. Peacock. Patricia M.. Zhang. Wen-Jing. Trimpin. Sarah. Advances in Ionization for Mass Spectrometry. Analytical Chemistry. 89. 1. 2017. 372–388. 0003-2700. 10.1021/acs.analchem.6b04348.
9. Li. Jing. Inutan. Ellen D.. Wang. Beixi. Lietz. Christopher B.. Green. Daniel R.. Manly. Cory D.. Richards. Alicia L.. Marshall. Darrell D.. Lingenfelter. Steven. Ren. Yue. Trimpin. Sarah. Matrix Assisted Ionization: New Aromatic and Nonaromatic Matrix Compounds Producing Multiply Charged Lipid, Peptide, and Protein Ions in the Positive and Negative Mode Observed Directly from Surfaces. Journal of the American Society for Mass Spectrometry. 23. 10. 2012. 1625–1643. 1044-0305. 10.1007/s13361-012-0413-z. 2012JASMS..23.1625L. free.
10. 1981. Fast atom bombardment: a new mass spectrometric method for peptide sequence analysis. Biochem. Biophys. Res. Commun.. 101. 2. 623–31. 10.1016/0006-291X(81)91304-8. 7306100. Morris HR, Panico M, Barber M, Bordoli RS, Sedgwick RD, Tyler A.