title: Quantitative analysis of low molecular weight compounds of biological interest by matrix-assisted laser desorption ionization.
abstract: Internal standards were used to demonstrate that matrix-assisted laser desorption/ionization (MALDI) mass spectrometry can be applied to the quantitative analysis of low molecular weight polar compounds. Three examples were tested: a standard curve for 3,4-dihydroxyphenylalanine (DOPA) was prepared using a stable isotope analogue (i.e., [13C6]DOPA) as an internal standard; [2H16]-acetylcholine was employed as an internal standard for the quantification of acetylcholine; and in the final example, the peptide Ac-Ser-Ile-Arg-His-Tyr-NH2 was used as an internal standard for the quantification of the peptide H-Ser-Ala-Leu-Arg-His-Tyr-NH2. In each instance, straight line fits (r2 > 0.95) demonstrate that MALDI is a viable approach for the quantitative analysis of low molecular weight analytes.
authors.affiliation: Biomedical Mass Spectrometry Unit, University of New South Wales, Kensington, Australia.
authors.forename: M W
authors.initials: MW
authors.lastname: Duncan
authors.forename: G
authors.initials: G
authors.lastname: Matanovic
authors.forename: A
authors.initials: A
authors.lastname: Cerpa-Poljak
mesh_terms: D000109:Acetylcholine / Q000032:analysis*; D003373:Coumaric Acids / Q000032:analysis*; D004295:Dihydroxyphenylalanine / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods
chemical_list: D003373:Coumaric Acids; C007175:alpha-cyano-4-hydroxycinnamate; D004295:Dihydroxyphenylalanine; D000109:Acetylcholine