Mw. Duncan et al., QUANTITATIVE-ANALYSIS OF LOW-MOLECULAR-WEIGHT COMPOUNDS OF BIOLOGICALINTEREST BY MATRIX-ASSISTED LASER-DESORPTION IONIZATION, Rapid communications in mass spectrometry, 7(12), 1993, pp. 1090-1094
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., [C-13(6)]DO
PA) as an internal standard; [H-2(16)]-acetylcholine was employed as a
n internal standard for the quantification of acetylcholine; and in th
e 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) dem
onstrate that MALDI is a viable approach for the quantitative analysis
of low molecular weight analytes.