title: Desorption/ionization of biomolecules from aqueous solutions at atmospheric pressure using an infrared laser at 3 microm.
abstract: A new atmospheric pressure (AP) infrared (IR) matrix-assisted laser desorption/ionization (MALDI) ion source was developed and interfaced with a Thermo Finnigan LCQ ion trap mass spectrometer. The source utilized a miniature all-solid-state optical parametric oscillator (OPO)-based IR laser system tunable in the lambda = 1.5-4 microm spectral range and a nitrogen ultraviolet (UV) laser (lambda = 337 nm) for use in comparative studies. The system demonstrated comparable performance at 3 microm and 337 nm wavelengths if UV matrices were used. However, AP IR-MALDI using a 3 microm wavelength showed good performance with a much broader choice of matrices including glycerol and liquid water. AP IR-MALDI mass spectra of peptides in the mass range up to 2000 Da were obtained directly from aqueous solutions at atmospheric conditions for the first time. A potential use of the new AP IR-MALDI ion source includes direct MS analysis of biological cells and tissues in a normal atmospheric environment as well as on-line coupling of mass spectrometers with liquid separation techniques.
authors.affiliation: MassTech Inc, Burtonsville, Maryland 20866, USA.
authors.forename: Victor V
authors.initials: VV
authors.lastname: Laiko
authors.forename: Nelli I
authors.initials: NI
authors.lastname: Taranenko
authors.forename: Vadym D
authors.initials: VD
authors.lastname: Berkout
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Yakshin
authors.forename: Coorg R
authors.initials: CR
authors.lastname: Prasad
authors.forename: H Sang
authors.initials: HS
authors.lastname: Lee
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Doroshenko
mesh_terms: D000399:Air Pressure; D007259:Infrared Rays; D007834:Lasers; D010455:Peptides / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D010455:Peptides; D012996:Solutions; D014867:Water