title: Matrix-assisted laser desorption/ionization mass spectrometry using a visible laser.
abstract: Visible matrix-assisted laser desorption/ionization (VIS-MALDI) was performed using 2-amino-3-nitrophenol as matrix. The matrix is of near-neutral pH, and has an optical absorption band in the near-UV and visible region. A frequency-doubled Nd:YAG laser operated at 532 nm wavelength was used for matrix excitation and comparisons were made with a frequency-tripled Nd:YAG laser (355 nm). Visible and ultraviolet (UV)-MALDI produce similar mass spectra for peptides, polymers, and small proteins with comparable sensitivities. Due to the smaller optical absorption coefficient of the matrix at 532 nm wavelength, the optical penetration depth is larger, and the sample consumption per laser shot in VIS-MALDI is higher than that of UV-MALDI. Nevertheless, VIS-MALDI using 2-amino-3-nitrophenol as matrix may offer a complementary technique to the conventional UV-MALDI method in applications where deeper laser penetration is required.
authors.affiliation: Interdisciplinary Graduate School of Medical and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511, Japan.
authors.forename: Lee Chuin
authors.initials: LC
authors.lastname: Chen
authors.forename: Daiki
authors.initials: D
authors.lastname: Asakawa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hori
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hiraoka
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000737:chemistry; D000803:Angiotensin I / Q000737:chemistry; D009596:Nitrophenols / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D009596:Nitrophenols; D000324:Adrenocorticotropic Hormone; D000803:Angiotensin I; C036645:2-amino-4-nitrophenol