title: Continuous flow atmospheric pressure laser desorption/ionization using a 6-7-µm-band mid-infrared tunable laser for biomolecular mass spectrometry.
abstract: A continuous flow atmospheric pressure laser desorption/ionization technique using a porous stainless steel probe and a 6-7-µm-band mid-infrared tunable laser was developed. This ion source is capable of direct ionization from a continuous flow with a high temporal stability. The 6-7-µm wavelength region corresponds to the characteristic absorption bands of various molecular vibration modes, including O-H, C=O, CH3 and C-N bonds. Consequently, many organic compounds and solvents, including water, have characteristic absorption peaks in this region. This ion source requires no additional matrix, and utilizes water or acetonitrile as the solvent matrix at several absorption peak wavelengths (6.05 and 7.27 µm, respectively). The distribution of multiply-charged peptide ions is extremely sensitive to the temperature of the heated capillary, which is the inlet of the mass spectrometer. This ionization technique has potential for the interface of liquid chromatography/mass spectrometry (LC/MS).
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. hiraguchi-r@mb.see.eng.osaka-u.ac.jp.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Hiraguchi
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. hazama-h@see.eng.osaka-u.ac.jp.
authors.forename: Hisanao
authors.initials: H
authors.lastname: Hazama
authors.affiliation: JEOL Ltd., 1156 Nakagamicho, Akishima, Tokyo 196-0022, Japan. ksenoo@jeol.co.jp.
authors.forename: Kenichirou
authors.initials: K
authors.lastname: Senoo
authors.affiliation: JEOL Ltd., 1156 Nakagamicho, Akishima, Tokyo 196-0022, Japan. yyahata@jeol.co.jp.
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Yahata
authors.affiliation: Suntory Institute for Bioorganic Research, Suntory Foundation for Life Sciences, 1-1-1 Wakayamadai, Shimamotocho, Mishimagun, Osaka 618-0024, Japan. katsuyoshimasuda@hotmail.co.jp.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Masuda
authors.affiliation: Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. awazu@see.eng.osaka-u.ac.jp.
authors.forename: Kunio
authors.initials: K
authors.lastname: Awazu
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid; D007477:Ions / Q000737:chemistry; D010455:Peptides / Q000032:analysis*; D016062:Porosity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D013193:Stainless Steel / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D007477:Ions; D010455:Peptides; D014867:Water; D013193:Stainless Steel; C032159:acetonitrile